 You know, let's, let's begin with excellent good. I think the broadcast is, I'm just checking if the YouTube is really started or not. Yes, beautiful. I think the YouTube is just started as you can see on the screen. Anyone who wants to have a look at the screen can also go in there. Good. Okay. Yeah. Now, so let's understand what are the important aspects of general organic chemistry. You know, so the very first things is actually how to draw a bond line structure, a condensed structure. So bond line structure is, for example, you know, when you only are drawing sticks. So this is your propane, you know, sorry, this is the one, two, three, four. Yeah. So this is dimethyl propane in, you know, two, two dimethyl propane, right? So this is a, this is our typical bond line structure that we, we have. Now, apart from this, you also have condensed formula. Condensed formula is when you are, for example, writing something like C2H6. So this is called as a bond line structure. Sometimes, you know, it's also very commonly colloquially called as the stick method. The second is C2H6 where you do not write it as CH3, CH3, but you just write C2H6. This is a condensed structural formula. It's called as a condensed structural formula. These are very basic things, but I guess it's good to really look at them once. The third way to really write molecular formulas is when you are writing structural formula. And the structural formula, you basically are noting some bonds. For example, when you write this as CH3 and CH3, you, you know, this is how you write the structural formula. And then there is a fourth one, which is an expanded form. In the expanded form, you write, you know, all the hydrogens, all the everything that that is basically worth writing, you write that. Okay. So this is an expanded form of writing molecular formulas, a formulae in the organics. And the last one is when you actually draw a 3D structure, you know, this is a three dimensional representation. In three dimensional representation, we actually show, for example, the same same methane can be shown with a wedge and dash. Okay, so this is a wedge. And then there is a dash. Okay, so this dash basically means that something is going inside the plane of paper, something is outside. This is a hydrogen when, when you are simply drawing a line, it means it is in the plane of paper. This is coming out of the plane of paper. And this is actually going inside the plane of paper. So this is a, yeah, yes, Akshath. Yeah, Akshath, if you want. No, Akshath, you're not audible. I think it's the internet problem at your end. All the others, are you able to hear me pretty well? Yes, sir. Clearly, sir. Okay, so I think Akshath, is the internet problem at your end. You can switch to the YouTube if you want, but at the same time, keep logged on to this also, whichever suits you. No, I'm sorry, Akshath, nothing is audible, actually. Okay, what I'm going to do is, Akshath, I'm just messaging you. Okay, now, another 3D representation can also happen in terms of projections. And there are three types of projections. Okay. The very first projection is called as a Seahorse projection. Okay, Seahorse projection. This projection basically means that you're drawing something like this. Okay, so this is how a methane would look like. Okay, so you're drawing as if, you know, you are looking at it as a model from some distance. You'll have this carbon, carbon, carbon here, all of these. So the carbons are not represented in the Seahorse section. Sorry, these would be the hydrogens. Okay, not the carbons. So I'm drawing a structure for basically ethane. So you have all the hydrogens coming up. These are the carbons at the center. These are again the hydrogens that are there. This is a typical Seahorse structure. And the second type of representation that you have for three dimensional structures is what we call as the Newman projection, Newman projection. In the Newman projection, what you have is basically you have a circle which represents the carbon from the center of the circle. You'll have three hydrogens coming out. Okay, sorry. And you have one more getting out. Akshad, you'll need to mute your phone. Okay, then you have another hydrogens coming out and there is a hydrogen here and a hydrogen here. So basically the carbon, the second carbon that is there is behind the first carbon. And therefore this circle is basically eclipsing the circle behind it, which is another carbon. And you can see the six hydrogens. What are the points to note? The lines that are coming from the center of the circle basically denote as if the hydrogens are on this circle. And the lines that are coming from behind the circle are the hydrogens that are attached to the carbon that is at the back. So these both are both ethanes that I've drawn in two different structures. One is the Seahorse projection. Second is a Newman projection, three dimensional projection. The last thing that we have is what we call as the Fisher projection. Now, Fisher projection is basically like pluses. Now in the pluses, please note that the ones that are on the right and the left are considered to come out of the page and the ones that are at the top and the bottom are considered to go inside the page. So if I have to draw this molecule, let me write this as ABCD for your recognition, then this molecule is actually going to look something like this. So this is the carbon at the center. The B is going to come out of the page. So it is going to be, okay, this is going to be B. D is going to go inside of the page. This is going to be D. A will be the one that will be in this and B. So this is how the molecule looks like. Please note that this kind of a structure is as if we are seeing it from this angle. So this is our eye and we are looking at it like this. So if I'm looking at it like this, I'm going to realize this as B, then this will be B. I'm sorry, this is going to be A and C. This is going to be C. Okay, this is going to be A and this is going to be C. So if I'm looking from this angle, so remember the right and left one, the ones that are horizontal actually come out of the paper. So these are both coming towards you on your face. It's like from here, it's going to come out of the screen onto your face and these two are going to go away from you. So this is basically going to bend something like this going inside and these two are going to come out as if they are coming towards us. So this is how they are going to come towards us. So that's the way Fisher projections are represented. This understanding of the three dimensional way is very, very important. I hope you guys are getting it. If you don't get it, please stop me at that very moment and I'll explain you the same. So three dimensional representations are done in three types of projections. So what do you mean by projection is basically something that is used to represent three dimensional objects. Now, so once we've understood this, the next important thing to understand is what are basically primary, secondary, ISO and all this. Few people still have a confusion as to what is a new, what is a third, etc. Now let's understand what are the first primary alkyls. So when a carbon is one degree, it is one degree carbon, it is called as the primary carbon. And it's generally represented by the symbol N. N means straight chain. There is no normal, no extension. So for example, when you have something like this, it is called as an N-propyl group. And if you have a, if you just close this with a hydrogen, for example, you say this is a CH3, CH3, then this is going to be N-propane, nothing else, N-propane with a CH2 here, of course. Now the same thing, when you have one branching, the minute you get one two degree carbon, you end up calling it an ISO. So for example, this is an isopropyl. So the iso word comes from one two degree, minimum one two degree carbon. So if you have minimum one two degree carbon inside the group, it is called as an iso group. Now please note, here it is directly attached to the two degree carbon, but this is basically isopropyl. But sometimes you might have that it is not attached to two degree carbon like this. So here the other group, R group is attached to a group which has one two degree carbon, but is not attached directly, the R group is not attached directly to the two degree carbon, it is attached to the one degree carbon. This still is called as an isobutyl. So what is the condition? The condition to write ISO is having minimum one butyl. See these are very fundamental concepts, but a lot of people go wrong with this. Generally they feel that this is not an isobutyl or they call it a turd or something else. So the only condition to have an iso group is when you have a two degree carbon involved inside the group. No three degrees, so the highest amount of degree that is two degree. The moment you get a three degree carbon, it will not be an iso group. The next is for example, I can also show you one which is going so long and then you have this. Now this entire thing is called as isopental. Now please note that although this group is called as isopental because there are five carbons, if we switch this to a common nomenclature, the common nomenclature is going to recognize this as butane or butyl group, not a pentyl group, please note. In common nomenclature you will have this as pentyl. In IUPSC it is going to be butyl. In IUPSC there are four carbons and therefore this is going to be considered as a main chain and into the bracket we will be putting this as a complex substituent and this will be a methyl on the butyl group. But in common nomenclature we are going to say this is isopental, IUPSC only butyl and common nomenclature isopental. So that's the isocompounds for us. Let's look at the next group which is called as the secondary group, secondary butyl. Now in secondary butyl group you still have a 2 degree carbon but the most important thing is the R group is attached to this. So the R group is attached to the 2 degree carbon. So when this R is attached to 2 degree carbon it is called as a sec butyl. So what is the difference between isobutyl and sec butyl? Sec butyl is also a component very similar to isobutyl. The only difference is the attachment is to the 2 degree carbon but it is not to the 1 degree carbon as is an isobutyl. So isobutyl I am just going to write besides this for you so that you have a clear idea. So this is isobutyl. This group is isobutyl whereas this is sec butyl. Now let's look at third butyl. Now the third the first group that can happen with the third formula is only butyl. You cannot have a propyl or anything with a third. Similarly you cannot have a sec propyl. It will always be isopropyl. So propyl is the first one where isopropyl begins. You cannot have an iso in ethyl. The propyl will have only isopropyl. In butyl you will have second isobutyl and in third butyl you will have a carbon which is 3. So this is a 3 degree carbon. The moment you get a 3 degree carbon this is the first one which can have a third and there is only one possibility. The moment you attach it here it's going to be isobutyl. So therefore you know the only possibility that you can have with the 3 degree one is the third butyl possibility. Now let's understand what will be a third pentyl. Now in the third pentyl also you will need to have the carbon attached to the carbon attached to a 3 degree carbon. So this is a third pentyl okay third pentyl okay and this is a third butyl okay. So that's that's that's one. Now what happens if if I draw a structure like this okay carbon carbon and this is attached right. So these two carbons I simply shifted from the end carbon to the central carbon and then now I'm questioning this is called as neo pentyl neo pentyl okay. So pentyl is the first group. So look third was the first group which happened in butyl now pentyl is the first group which will happen with a neo thing there cannot be a neo butyl it's not a possibility right. So these are so I think this clarifies you know if you if you ever go back to this lecture and listen to it one more time you'll realize that you know the differences between all of these groups okay going forward. Now okay now we all know about you know how alky alkynyl and all of these groups are considered. Now what we want to talk about is basically different types of nomenclature of functional groups. I think nomenclature is something that most of you still you know want to have kind of a quick overview on. Now there is actually a scheme where so for example you know before before we go to nomenclature I'm also going to talk about one degree two degree amines or for example you know thiols right as such group. So when you have nitrogen attached to two carbons okay our dash then it is a two degree if it is attached to one it is one degree we all know this right. Similarly it is also with sulfur when sulfur is attached to you know two carbon atoms it becomes a thio ether okay this is a thio ether because it very much looks like ether but when sulfur is actually attached to only one this becomes a hydrogen sulfide you know so alkyl hydrogen sulfide or say thiols this can also be sometimes called as thiols okay. So basically it is just an alcohol without an oxygen but with a with a sulfur in it okay. Now let's let's look at what are homologous series so every you know if you remember homologous series are homologous series are the ones which has the same general formula okay but different structures okay different molecular formula also in fact okay molecular formula. Now what do you mean by general formula for example alkenes are cn h2n plus 2 right these are alkenes now similarly amides for example you know amines not amides but amines would be cn h2n plus 1 n h2 or you can just add that here and you can say cn h2n plus 3 n okay so this is a formula for amines one degree amines in fact okay so having a common formula is what is called as a series and why is it see it's not called as a group please note it's called as a series because it is sequential one after the other as you keep on increasing the value of n from 1 to 2 to 3 to 4 to 5 and so on so forth you'll find that different amount of alkenes and alkenes can also be realized so that's that's that's that's one thing that we have okay now now majorly you know there are three different types of name nomenclatures you you must have heard about common and iupsc definitely but there is something also called as you know derived system now what is it derived so common nomenclature is where you know you have some names which you know which which basically are used from iso and neo and simply using it right from alkyl groups and you can name them and but and iupsc are a very set set rules which have been defined and every day as we speak you are able to actually you know name them but what is a derived system okay so according to this system any compound is given its name based on its homologous series okay for example if you have alkene then you know naming it as ethylene or alkenol carbonyl based on that you will name so it's it's kind of in between you know iupsc and you know the common names for example in common names you know i would prefer symmetrical saying so I'll draw a molecule for you okay now in this system this system according to iupsc would be basically two butene okay but if you really look at common name the common name for this would be simply ethyne you know ethyne ethyne in terms of dimethyl ethyne or something of that sort but then derived name is where this name is derived from this functional group and it is actually written as dimethyl ethylene okay dimethyl ethylene here it is written also sometimes you also write as unsymmetrical dimethyl ethylene in now why does that sorry this is a symmetrical one because cs3 is on both the sides so this is a symmetrical dimethyl ethylene symmetrical yeah but sometimes you also have this as unsymmetrical dimethyl ethylene where the double bond is here and hh and a ch3 ch3 okay so this is an unsymmetrical dimethyl ethylene so what is what is basically a derived system derived system is we consider this molecule as a derivative of the family that it comes from and the family here is an ethyne family so we are saying boss it is an ethylene simply but you know there are two mythiles therefore this is dimethyl ethylene there might not necessarily be a common name for this but definitely there will always exist an iopc name okay so so that's yeah so that's that's the derived systems now let's look at I have also given you an entire list of you know hierarchy that of all the compounds in nomenclature that you might have just for having a copy handy with us for the timing i'm just going to put out an image priority it's called as the priority of functional groups in nomenclature okay yeah and you'll realize that this is something that you can always you'll you'll need to remember and you'll you'll have to memorize this so carboxylic acid is the top one top most one and then there is ester and then you go to amide now i'll tell you a trick how to really remember this if you see all of these actually start from the oxidation states of carbon so for example the most important is carboxylic acid it has the highest number of oxygens the second is actually ester because you know ester has the same thing but hydrogen is missing so you have r here then actually you will find that you will come to amides you know which is c double bond o n h2 so you this is where you are for the first time actually removed oxygen but having removed oxygen oxygen you still are having another functional group inside it so after amides you will realize that the next that you can actually go to is ketones you know so between amides and this you can also have acid halides you know or what we call as okay so this you can have here as c double bond o and x okay so acid halides then you have amides and then you can actually end up going to acid anhydrides okay this is for the first time that you're actually now partially taking out you know the other oxygen also so now you are still half the oxygen is shared and therefore you can come in here and then comes actually your acetyl dehyde okay where you have cOH so I'm still having something here it is not still not going and after aldehydes you have CN which is nitrides right and then comes your c double bond o okay so if you really look at carboxy acid it's double o double o you're also amides cON you know nitrile CN then comes your aldehyde and then comes ketone finally alcohol right so CN aldehyde then ketone so how we are going from top to bottom is we are slowly trying to remove the involvement of oxygen as much as possible here there are two oxygen here there are two oxygen finally there is half of oxygen here generally acid anhydrides are also used at the top you know before acid halides but having said that as soon as halides come in the entire oxygen is gone so between check between acid halides acid amides and acetyl dehydes you know of course the X is the top priority then nitrogen and then hydrogen this is going from the biggest non-metal to the nitrogen family to the hydrogen family so that's how the priority decreases after this is entirely removed actually you know nitrogen is giving the oxidation state of almost minus 3 to this sorry plus 3 to carbon so that's where we come in here and then we have COH and of course then it will end up going to alkene alkynes and alkenes but please note that alkene the double bond is given larger priority than triple bonds okay this is something that we definitely have to remember most of the times this is the matter of confusion generally they are considered similarly similar if there is a large difference in numbering but if there is a small difference in numbering alkenes are preferred than alkynes and then comes your alkenes and if you if you see ethers and halides halides are actually given the last position so Rx in fact do you know we in IUPC nomenclature we never write it as ethyl chloride this is wrong writing in IUPC this is a common name so in IUPC in fact we say this as chloroethane whereas if you have to write carboxylic acid we will say it as ethanoic acid so in IUPC a lot of importance is given to the suffix if it is a functional group but acid it is just the halogen group which is absolutely not even considered even for for example ethoxy ethers so ethers actually come here ROR dash so both for ethers and this we do not even consider a suffix a suffix is not written at all a prefix is written for this we call this as alkoxy alkane alkoxy alkane so this will be for example methoxy propane or ethoxy butane so there is this is actually considered as a prefix and this also is basically a halo alkane a halo alkane okay so what I'm trying to say is that in the nomenclature the ether group the oxygen group and the chlorate this halo group both of them are not even given a priority to to be named as the suffix you know because they are lowest in the priority order so what you see on the screen is the priority order of nomenclature now let's look at the rules the rules of nomenclature that we have the first rule is the longest chain rule okay so can you just go back to the previous game for two minutes yeah go on anything that you want to ask no so I just wanted to actually copy it down yeah you know you will have this on the youtube so you can always take it down from there yeah so yes sir yeah okay now let's go to the rules of nomenclature the first rule is the longest chain now there are three problems with this longest chain rule okay or three what you can say not a problem exactly but three conflicts that might happen the first conflict is a conflict of only substituents okay so the rule here is have maximum substituents maximum substituents plus the longest chain so you have to choose that longest chain so if there is a problem with two longest chains saying that look both of these longest chains are possible both of them have the same number of carbons let's say eight and eight carbons then choose that longest chain which has maximum substituents okay so let's say there are two branches one like this and the second like this right and on on this two brand on two two trunks I would say trunks and on these two trunks there are there are three branches so these are the three branches that you have and on this trunk you have two branches right so if even if at this there are eight carbons and eight carbons here I will be choosing this and not this the reason is the number of substituents here are lesser please note that the number of substituents on this branch is one two and the three one there is a number of substituents on this branch is one two three and the fourth one so there are four substituents here and there are three substituents here and therefore I will be choosing the one with the four substituents the reason for this rule is that the moment you choose maximum number of substituents your nomenclature becomes simple why because look when you're taking all of these this is your complex branch and if you go through this path let me name them a b and c if you have chosen an ab path then you are let's say your ec path is a complex substituent on the ab trunk the ab is your trunk and your ec is the branch on this trunk which is a complex substituent why complex because the substituent itself also has its own branches right now in that scenario naming this complex substituent is going to be difficult so the lesser difficult it is the easier to name and therefore the complexity of the branch has to be reduced and the complexity of the branch can only be reduced if you are able to take maximum branching on the trunk so on bc we are taking maximum branching so that this becomes a less complicated substituent and therefore your naming is easy so the first rule is substituent rule which is if you have two branches which have the same longest chain then choose that branch which has maximum substituents now the functional group rule if there is a conflict between longest chain and functional group choose the functional group as the longest chain for example you have this as the longest chain and let's say this is the smallest smaller chain okay so this is b this is c and this is a so ac has let's say six carbons and bc has eight carbons but the problem is here there is an OH and here there is an X okay not X let's say there is a CHO okay now you will have to choose if it is a terminal carbon if it is a terminal carbon functional group you have to start from the terminal carbon functional group only but please remember in case of multiple functional groups the priority will proceed which means if there is for example OH and CHO of course CHO is better than this I will have to start from here only and go this side and what do I have to start from here the numbering the numbering that I'm talking about right so what is the rule the rule is even if there is a longer chain in the longer chain if I'm not able to take both the functional groups keep the chain smaller yet take both the functional groups okay so functional groups with priority functional groups with priority is precedes over being a longer chain having said this you have to choose the chain such that you can go to the maximum amount of carbons taking in considering maximum amount of functional groups I repeat you have to take maximum amount of carbons taking in consideration maximum number of functional groups that are there okay now in this scenario there might there is only one exception and that exception is for again ethers the exception is for ethers and for halides okay now if you are seeing the previous equation in the previous equation we have seen that alkanes are preferred over ethers and halides which means if there is a longer chain of alkanes possible you can simply take ethers and halo alkanes as a substituent and move on you don't have to really consider them in the priority you have to choose the longest chain and which is which is what alkanes are defined about so you have to change choose the longest chain you don't have to choose these two as being a priority and take the chain with them in in in world you have if there is an eight so I'll give you an example exactly so look this is an eight chain carbon and let's say there is an ether here instead of alcohol okay and you're also let's say there is a halide okay instead of this there is an halide okay X now I will not choose this chain I will choose BC this is not relevant for me I will choose BC and move on why because alkanes is preferred over ethers and halides right so these are the two exceptions for the functional group rule now what happens when you have functional groups and substituents both of them together the rule is simple take maximum functional groups with priority so take maximal functional groups in the functional groups I'm writing in rocket priority has to be retained okay and then go for maximum branching maximum branching okay so take maximum functional groups on the trunk plus C to it that if you're able to take maximum branching take that also and then go for the longest chain which can have both of these taken care of is everybody connecting to this give me a quick shout is that is that good yeah so yes good excellent so this is these are very important rules you know for for you to really remember you know it cannot be more clearer than this you know I think most of the textbooks also do not say with that clarity but you know now what happens when you encounter so this is the first rule let me finish all the three rules and then I will come to complex substituents now what happens to your numbering okay now numbering also has the same rules just slightly modified the first numbering rule is first start numbering so that you get smallest sum smallest sum so if you are simply an alkane okay you are simply an alkane and then you have these kind of stuff start from this side so that your sum is smallest okay the second kind of a rule that you will always encounter is start numbering says that the first difference is smaller the first difference is smaller okay now what does this mean if I'm going from this and I'm going down let's say I have two tracks okay and here I have let's say at the fourth carbon and here I'm getting at the fifth carbon okay the branching this this is the fifth carbon branching and this is the fourth carbon branching then when I'm going through these two tracks both of these tracks have to be 88 numbered if they would have not been 88 numbered then of course the previous rule will follow in the numbering you go where is the first difference happening after the common thing this is one two maybe a third carbon here this is common for both because this is a branched carbon right the difference is at the fourth and fifth so the first difference is followed and lowest first difference is taken so this is the lowest first difference for this is preferred and bent forward okay so smallest sum if you have direct summability okay of all the groups if not at least go for the first small difference that's the numbering rule then what if there is a functional group go for that functional group which is higher in priority higher priority functional group gets this smaller number higher priority functional group gets the smaller number okay so that's the functional group priority right and if there are multiple functional groups then you go for the smallest sum smallest sum for multiple similar small smallest sum for multiple similar functional groups okay functional groups for example you have a branch in this branch you have an OH and you have an OH okay now in this scenario let's say this OH is at one and six okay and from the other side it is at two and two and probably seven okay right now one and six gives you a shooting gives you a sum of seven two and seven gives you a sum of nine so I will go for this okay not this simple as that okay so smallest sum so this is smaller the smallest sum here is for branching okay then I have mentioned that the first difference has to be smaller wherever the difference occurs then the third one is that the functional group the higher priority functional group has to get smaller number for example if there would have been a COOH here I do not even have to count I have to start from here that's it nothing doing I have to start from here period even if it will go to a smaller chain or everything else collapses doesn't matter if the functional group has a higher priority then just start from that functional group and move on if it is a terminal carbon you don't even have to think you have to just start from the terminal carbon and reach the maximum possibility that's one now if that is not done in the when you have multiple such functional groups then you'll have to look at the sum and the sum has to be smaller okay so so that's those are the couple of rules that we we can look at right the third rule is whenever you have a group a branch or a functional group whatever you have let's say you have this you have this you have this you have this the number of branches that are there all of them should receive a number for example it can be 2 comma 2 dimethyl okay each each of the branch has to be reported each branch has to be reported okay so 2 2 dimethyl sometimes you will get 3 5 di alcoxy group okay so this is where OROR is written or you'll get 2 3 4 8 tetramethyl tetramethyl okay all of this is also allowed okay but remember I have written four there are four methyl groups so I have numbered given number for each one of them here there are two methyl groups they are on the same carbon so I've written 2 2 twice it doesn't matter you write it twice right and then after that you write dimethyl okay so it can also be for example 2 2 4 8 tetramethyl so which means that 2 2 are here this is a 4 and this is an 8 but this was the second carbon so at the second carbon there are two methyl at the third carbon there is a 4 at the fourth carbon there is a methyl and at the 8 carbon there is a methyl so this is 2 2 4 8 tetramethyl okay Kevin are you there are you connecting okay all this you're able to comprehend you're able to get it right well excellent please ask if you if you get stuck anywhere sundar all well sundar okay good now now again so I think I have covered most of these rules now the last rule is when you are writing these these all of these molecules you have to start writing with you know in the alphabetical order okay so in the alphabetical order you will consider you know all the group parent group name for example in dimethyl you do not consider d you consider m please note everyone gets confused in this so if there is dimethyl dimethyl tetra ethyl okay dimethyl tetra ethyl okay in this scenario dimethyl tetra ethyl is the wrong way to write the right way to write is tetra ethyl tetra ethyl dimethyl okay why because this e and m is what is considered as the alphabetical order not d and t so d and t is wrong this dion tetra are not considered e and m are considered this is this is rule number one in alphabetical order the second rule in the alphabetical order is isopropyl isopropyl neopropyl okay are directly taken as it is from the common nomenclature in alphabetical order so you can write isopropyl and here i and n are considered as the alphabetical order okay not the other way round okay just give me one second guys i'm just going to be back in a minute yeah okay i'm back so yeah so i think we have seen the rules of alphabetical order as well and you know this this actually more or less completes nomenclature okay now yeah perfect now let's go to nomenclatures of probably you know cyclic compounds now there are two types of cyclic compounds okay or i don't know if we should we can take the nomenclature of cyclic let me check okay so let's let's do it you know it doesn't matter you know let's continue with this now the second group of nomenclatures this is all for you know straight chain compounds that is aliphatic compounds now whenever you have alicyclic compounds nomenclature for alicyclic ones so there the rules are slightly different for alicyclic okay now obviously you know when you in an alicyclic whenever there is a cycle you will start naming with the compound of the cycle itself you know so if there is a competition between straight chain and cycle you know you always prefer the cycles over over the straight chain okay but you know if there are no single or double bonds it is still probably a cycloalkane or a cycloxene if there is a double bond and a cycloxine if there is a triple bond okay now how does this really work so let's let's take an example you have this molecule okay and you have a ch3 year and you have let's say another c2h5 year now all you need to do is you will start naming from the molecule which is alphabetical in order because if I name from here this becomes one so you basically number it around and you need to get to the lowest sum so if you number this becomes one two three four from this side but from this side it becomes one two and three and since this is the lowest number I can go from here but then I have two choices right I can number this as one three or I can start one from here and I can come three year as well right so the the idea here is that whatever are the rules for aliphatic all of them are more or less followed very similar to alicyclic as well and therefore this is not one methyl three ethyl but it is one ethyl three methyl okay so this is one ethyl and three methyl okay so here what we have done is we have we have maintained the alphabetical order and we this cycle this will be cyclopentane okay and that's how that's how we have written it right now if there are multiple bonds then obviously you know you go with the bonding first so let me give another example let's say you have a molecule like this okay and you have a c2h5 and you have a ch3 now in this scenario I will give preference to alkenes and and then the alkyl groups and I cannot help but I have to start numbering from here because that's the way that you know the double bond can be encountered right fastest now this will be second and this will be third so this actually becomes a two ethyl two ethyl and three methyl three methyl cyclopentene and that pentene I will have to write pent slash one ene okay so that will give me a cyclopentene group oh so I have a doubt yeah tell me so why can't we take one at the position of two don't we come across the double bond as well as ethyl at the same time look now wherever we put one so let's say if I put here at two how would I differentiate this okay for example c2h5 and ch3 how do you name this compound so if you if you take one at c2h5 wouldn't the sum be much lower that's what I'm saying so let's say I take one at c2h5 how would you name this compound if I take one here so in this compound if I would have taken one here and two here you would have named this compound like one ethyl okay that would be two methyl and cyclopentone ene okay this is how you would name this had I taken it at c2h5 yeah now let's try and do this for this this compound okay let's try and do it for this compound now in this compound you will name this compound as one ethyl okay because it is one here it will be two okay and that would be two methyl okay and cyclopent two ene but cyclopent one ene correct now if you go on in the first one when you when you've written one ethyl two methyl cyclopent one ene wouldn't it be cyclopent one two three four five five ene oh then then your lowest sum rule is getting violated any which ways yeah yeah so that's what I thought you were trying to explain so I'm confused as to how you have c2h5 at one and the double bond at one like good so see I can keep one here and two and three the other way is that I can start with see anyways I have to give priority to alkene okay if I keep one alkene year if I say one alkene year then I actually end up getting this compound okay I end up getting this compound so I cannot keep one alkene year the only way that I can have lowest sum as well as alkene being represented is by keeping the one year you're starting the alkene year if I start one alkene year then this becomes you know one ethyl two methyl and one cyclopentene which is nothing but this compound itself yeah learn by comparison are you able to compare and differentiate yes sir yes sir yeah Akshath if you still having a doubt please ask no no no it's okay it's okay you got it right now so just to show you the difference so what we're basically doing is just to have a difference in alkenes I will give the al you know the starting point of alkene sometimes a precedence and say that as one okay now sometimes you know if you are still very doubtful you can actually say one two cyclopentene that is also possible okay one two cyclopentene is very much you know accepted okay so here I can write one two cyclopentene that's also okay so that will actually you know help give in more clarity that the double bond was between one and two carbons as I'm numbering this functional group okay so that's a quick nomenclature for you know I'm just going to do one example so that you really realize okay now there is one more rule here which I I would like you to know for example let's say the the side chain contains a functional group you know something like this and you have a cyclopentene attached or a cyclic compound attached to it now only when the long this chain actually contains a functional group which is more in priority or which has probably a higher order functional group then this entire thing this cyclopropyl will become a branch to this now how will we name this is this so I start from here this will be one this is two and this is three right so this is actually three cyclopropyl three cyclopropyl prop one in prop one in okay three cyclopropyl prop one in now please note that you know we we will not write this we'll not start numbering from here because alkene being a functional group which whichever carbon the double bond starts that carbon is named as the first for example if I have a carbon chain like this C C C and COOH this carbon is going to be my first carbon I don't start from this carbon okay and I don't say this is as a propanoic acid I say this as butanoic acid because I need to start from COOH similarly alkene if it is at the terminal carbon you'll always start numbering from the terminal carbon itself okay that's that's one important thing now the other point that I'm trying to make is that you will have if the if the side chain is longer longer than the one that you actually have in the ring so that's rule number one that the side chain is longer okay side chain is longer and the second rule that we have is when when there is a functional group you know which is a high priority functional group or any functional group for that matter then this side chain is considered as the main chain or the root and the entire cyclo thing will become a substituent let me give you one more example okay let's say I have pentene and I have it attached to let's say a carbon like this okay so two three four five six so I have a six carbon here of course all the hydrogens are filled I'm just not writing them this will be actually one and two so this will be named as two cyclo cyclo pentyl okay hexane two cyclo pentyl hexane okay so the the functional groups and the length of the chain actually has a precedence over over the ring there is another exception to this also is that when you have multiple such rules right where for example you have cs3 and cl now then you cannot use this chain as this right so this entire thing will become you know isohexyl or isohexyl or you can simply say that this is one methyl so in the bracket you can write complex like one methyl one methyl pentyl okay because there are three carbons one two three one methyl pentyl and this entire thing can be written into bracket I'm just going to speak about this if you if you don't get it just the point that you want I want you to may understand right now is if there are multiple groups on this ring then the ring will take a precedence over the longer chain itself why because naming it through the ring is easy now this being a complex branch in itself there are rules to name the complex branch the first rule to name let me write it here complex branch rules and this is therefore aliphatic as well the rules for complex branches whichever is the carbon attached to the main trunk okay in this scenario our cycle is the trunk so the carbon attached to the main trunk that is given as the first number okay no doubt whether there is a functional group is whether there is not whatever it is this carbon is given as the first number and from here longest chain is sought so from here longest chain will be this so this will be 1 2 3 4 5 so this one now because will become the root so the root is now pentyl and on this longest chain there is one methyl on the first carbon so this is written as one methyl pentyl and this entire group is now this entire group is now one functional group and at what what where it is so if I have to name here I think the first nomenclature will go to this is a pentyl so that is P this is a methyl so M so M will get first so this will be 1 now if I go to chloro chloro will be 2 alkene yeah after so after alkene if this will be 2 actually because this is also an alkyl group so this will be 1 2 and 3 please note how I've done the numbering alkanes have a precedence over halide so I'm keeping halide at the last between alkanes methyl and pentyl these are the two that I have to give precedence so I will give it to methyl and then I will come to pentyl because this is a pentyl derivative it is no more an Hexyl derivative please note now this entire group this entire branch is written in the bracket this branch is at the second slot so I'm writing this as 2 dash pentyl and then I will write one methyl so one methyl will come first one methyl right after that I go to 2 pentyl after that I will go to sorry it's not 1 2 3 sorry I'm sorry that would be 3 5 no one pointed out are you guys there yeah so this will be 1 2 3 now how can it be 2 1 2 3 the ranking is third yeah and this is then fourth and this will be fifth okay so this is going to be 1 methyl 2 dash 1 methyl pentyl why because this entire group is at the third carbon not 2 at the third carbon okay so this is 1 methyl which is at the first carbon 3 1 3 dash 1 methyl pentyl this entire branch being a complex branch I've written after that it will be 5 chloro 5 chloro and then I will write this as cyclopentane yeah I just want to pause here have you got an entire thing how I did this do you want me to revise or repeat one more time yes sir you got you got can you repeat one okay okay so I'll repeat look now if earlier we were saying that the branch was longest and therefore the ring was a substituent to it and we said it is 2 cyclopentyl hexane okay because this is cyclopentane so it is 2 cyclopentyl hexane very easy to understand because the ring was larger now what happened is the ring had two more substituents so naming it through the larger one is difficult so what did we say look we are going to take the ring as the primary source and we will put all of these branches on the ring the ring will be our trunk or the root and these will be our branches fine agreed now if these are branches how do I name alkanes are more than highlights so I have to give alkanes the higher priority now between alkanes I have one methyl and second as a as a pentyl derivative not hexane pentyl derivative right so between methyl and pentyl who is alphabetically higher m is alphabetically higher so I'm going to write one methyl so while writing I'm going to write one methyl now how did this become a pentyl derivative at the third carbon the carbon that is attached to the trunk is given as the first number and no matter how many carbons are there attached to this it doesn't matter the carbon that is attached to the trunk is given the first number from there we start seeking the longest chain rule after this you know it simply is that you have to you have to forget whatever is below and then you have to really name this compound so then from here if I start numbering it becomes one two three four five this is the longest it is a pentane by its root and therefore since it is a pentane I will call this group as a pentyl group okay and on this pentane group there is a methyl that is attached to the first carbon because it came here so it is one methyl pentyl and I put a bracket the bracket denotes that it was a complex branch and this entire complex branch was attached to the main trunk at the third position okay why third because I had to start from methyl this was pentyl so methyl was given priority over pentyl so this becomes one two and three so the third carbon the complex branch is attached so it is three one methyl why one methyl because this is the methyl group that is attached to the pentane three so and it is attached at the first position okay so it is one methyl pentyl even if there would have been three other carbon here it would have been propyl one propyl pentyl please note it would not have been uh nonane it would or nonile it would have been propyl there would have been two carbon here it would have been one propyl pentyl only in spite of that so it will be one propyl pentyl okay and then this entire group is at third so three and then fourth and fifth carbon here so this is five chloro cyclopentene got this is everyone clear anyone who has any doubt or any other things or why it is not this and why it is not that no so perfect good so you you I think can now have understood complex branching also in complex branching all you have to do is put a bracket and inside the bracket you name like any other aliphatic rules and go on moving further right now after this then we are going to see how bicyclic compounds are named okay bicyclic what do you mean by bicyclic there are two types of compounds one a compounds which are between two carbons okay so you have bridges between carbons something like this okay so these are called as bicyclic compound there can be two three any number of bridges generally there are not more than three bridges sorry and then there is there are there are compounds which has you know just one carbon and from this one carbon there are you know branches coming out something like this and you know you know so this is a cyclo butane which is coming out of this carbon and then there is a cyclo propene coming out of this carbon right so any car any compound which is like this is called as a bicyclic compound bicyclic okay so when they are between two carbons these bicyclic compounds can also be like this for example i'm going to show you one more bicyclic this is a carbon this is a carbon and you have a a butane coming out of this okay or whatever coming out of this this is also a bicyclic compound because between two carbon there is a bridge okay between two carbons there is a bridge here there is no bridge you know it everything is just originating all the circles and angles are originating from one carbon here there are two circles originating from two carbons and therefore it is called as a bicyclo so this is a bicyclo this is actually a spiral compound this is such kind of compounds are called as pyro once again i'm saying this whenever everything all the circles and everything are originating from one carbon it is called as by spiral and whenever they originated from two carbons for example here there is a branching between two carbons these are the bridges they call and here there is also one bridge between two carbons so this is also both of these are bicyclo compounds now how are the bicyclo compounds named you identify yeah go on uh spiral compounds are bicyclic compounds so uh look this bicyclo is not in the terms of how many cycles are there or how many how many rings are there okay if you if you take from the normal english then this should actually be a tricyclo compound because there are three rings one is this ring that is the second ring and you know uh one two and third third this ring right there are three rings here but we don't call it as tricyclo okay so this bicyclo word in ibc comes from two carbons holding the bridges spiral comes from one carbon holding the rings this is two carbons holding the bridge and the ring so this is a bicyclo and this is a spiral getting me okay yeah okay now how do we name the uh firstly we look at how do we name bicyclo and then we'll go to the nomenclature of uh spiral compounds so in bicyclo what do you do is you take the carbons that are a bridge okay so let's say we have this kind of a compound okay let's say ch2 this and i will put maybe another ch2 here okay now in this scenario these two are called as the bridge carbons bridge head atoms okay so i'm making them a start so these are called as the bridge head atoms and these are called as this this one the one that are i'm i'm marking in in in in pink is basically all the bridges okay these are these are all the bridges okay so how do you start naming this the nomenclature of this carbon is that you firstly count how many number of total carbons are there okay so how many carbons are there one two three and four there are four carbons in this uh molecule and therefore the name of this molecule is going to be butane you know bicyclo butane okay now uh uh one second yeah so it's a bicyclo butane bicyclo butane okay now in bicyclo butane all that you have to measure is how many how many carbons are there right so here there are zero carbon here there is a one carbon here there is another one carbon so you start you start uh uh naming naming these carbons uh from as a number and you put these numbers into square brackets okay so you will write this as bicyclo okay you'll write this as bicyclo okay and you put a square bracket and you name them as one one zero okay so how many carbons are there between the bridge is mentioned and they are mentioned in a descending order this is very important one one zero and zero is also mentioned okay because there is one more bridge which has actually has zero carbons on the bridge so that is mentioned and then you will write this as butane okay so bicyclo one one zero butane that's that's how uh you would do it okay now uh let's do one more example and you I think that would be much more clearer so let's say we have a molecule like this okay and let's say like this okay now these two are the bridge carbons there are two carbons here two carbons here and one carbon here okay and uh the total number of carbons are one two three four five six seven so this is an heptane okay so is there seven one and two three three or yeah this is a heptane okay so this is bicyclo why bicyclo because two carbons are holding the bridge so bicyclo two two one two comma two comma one okay heptane okay bicyclo two two one heptane okay so that's uh that's a bicyclo uh neem okay now let's look at spiro uh okay now what happens if uh there is uh you know if uh if there is a double bond here for example the simple thing is you know you start numbering from the bridge carbon okay and you start going towards the the one the ring that is actually the uh having the functional group so one two three so you simply say here this would be hept two in okay bicyclo two two one hept two in okay but this kind of complexity I don't I don't see that you know you guys would be asked uh you know knowing till naming the alkanes is more than sufficient uh you know if required that's that's something a special case we might take later on let's look at spiro how are spiro defined okay in spiro for example this compound you know what we have let's say we have two triangles you know having uh meeting at one carbon this also is named in a very similar way so this is called a spiro which means that one carbon is holding stuff and how many carbons it is holding in both the rings there are two and two carbons here so it is written as two comma two again in the descending order and then total number of carbons is mentioned that is pentane okay let's do one more okay for example uh I'll I'll do one with a functional group for you so let's say we have a cyclohexane here and then we have a pentene here okay that this carbon okay we have a pentene and let's say there is a chlorine here okay so always start from this bridge carbon okay nomenclature or or you sorry not the bridge carbon the one that is next to the bridge carbon always start the one that is next to the bridge carbon not the bridge carbon you end it at bridge carbon I am repeating you end it at bridge carbon you start one from the next to so I have four choices I can start from here I can start from here I can start from here and I can start from here the the where you start is actually decided depending on what functional groups are you going to meet right so here this is the first and since there is a functional group I'll have to go in this direction only so this becomes spiro this becomes spiro in the bracket you will write this as how many carbon are there one two three four and here there are one two three four five so you'll write this into bracket as uh uh okay of yeah four five so you will say this as uh five and four and you will mention this as two chloro two chloro why because the chloro is at the second position so two chloro spiro three five sorry five four decain five four decain okay so that's that's how uh we would we would come in yeah now okay good so now that this is settled uh let's go to uh uh the next uh piece of so we are done with nomenclature anyone who has to who wants to ask anything on this all well no but yeah okay now let's go to isomerism right uh I think we have we have this itself has taken too much of time but we can do a couple of other things isomerism now there are multiple types of isomerism you know chain isomerism I'm not going to go into details I hope you guys remember chain isomerism means you know let's say this is a compound so this is how many four and uh so two plus three five and one this is six carbons right now the six carbons I can also write like this one two three four five and six okay so these both are basically what are isomers isomers I have the same molecular formula but different structures please note isomers are different from homologues in homologues you have the same general formula and you have different molecular formula itself these are different compounds that you have in isomerism also these are different compounds but the structure is different the molecular formula is the same okay so in this these two we will find that uh there is a chain structure that has changed and therefore these are chain isomers okay now what is a position isomer a position isomer is something which has difference in position so let's say in the same molecule I have a methyl group here CH3 group here now instead of that I am keeping the CH3 group here okay now please note if I keep the CH3 group here it's not going to create a different compound because they both are the second positions so that's why I'm putting it in the middle and therefore these two are position isomerisms which simply is this is the second position that it was and this is the third position that it has been so what changes positions substituents change position functional groups change position double bond change positions halide change positions anyone who is changing position but not changing the molecular formula is called as a position isomerism okay so that's second now let's let's talk about functional isomerism so functional isomerism means again the molecular formula remains same but the function itself differs let's look at an example so this is a CH3 C double bond OH CH3 okay and you have CH3 you know C OH and you have a double bond CH3 here so in this both the scenarios you know the molecular formula is going to remain the same but what has changed is the functional group see this is a ketone and this is alcohol now this functional group change between ketone and alcohol is also called as a special kind of isomerism which is a keto enol isomerism but it's called as tautomerism tautomerism okay so whenever it it simply happens whenever there is a there is a double bond that shifts that is a tautomerism okay double bond that shifts and you get a compound which is ketone and enol as well and we have seen these reactions right you know this tautomerism you know aldol condensations and all you know how you know similar but yeah it's CH2 right where it will be CH2 you're right okay so this will be a keto enol tautomerism now please note a function this is I've also explained this as the as a functional isomerism but there can be multiple types of functional isomerism I'll give you another example for example you can have CH3 CH2 and CH2 COOH but and you can also have CH3 CH sorry CH2 double bond CH then you get into an oxygen and then you have CH2 and then you have CH2 OH okay so look what is the formula for this the formula for this is C4 and how many hydrogens are there 3 plus 2 5 plus 2 7 plus 1 8 so H8 and O2 this is its molecular formula and this you have C there are four hydrocarbons again how many are hydrogen 2 plus 1 3 3 plus 2 5 5 plus 3 8 so this is again C4 H8 and O2 right so you have two different compounds having the same molecular formula but completely different functional groups here there is only carboxylic acid here there is an alkene and ether and then alcohol and these two are functional isomers right so these are all isomerisms that are possible in straight chain compounds okay now there is one more that you can actually remember which is called as metamerism okay now what is metamerism metamerism means in the same ether or wherever you have you know both sided functional groups for example you have CH3 OH CH2 CH2 CH3 okay so this is methyl propyl ether and you have CH3 CH2 OH CH2 CH3 so what has happened is nothing has changed except that the ether has has changed the arms that it has and it's not just ether it also is two degree amines it also is also is three degree amines so three degree amines it can change all the three arms that it have I hope you understand what what do I mean by arms it is the branching that originates from the oxygen and when the molecular formula remains the same but the branching changes so for example here we have ethyl here we have ethyl and ethyl here we have ethyl and propyl but the molecular formula remains the same this is called as metamerism okay right so so we have seen all so these are all the you know straight chain isomers that we actually do understand now let's understand stereo isomerism okay stereo now this this very word stereo comes from you know what it means is that the connectivity okay so isomerism right now when we when we had other isomerisms the connectivities were changing for example here the oxygen was connected to a methyl group and it was connected to a CS2 so the connectivities were changing but stereo isomerism where it means that the connectivity remains the same now let's understand what does it mean to have a connectivity being same now look we had I had shown you a seahorse projection where these are the carbons that we have okay now this carbon and this carbon has both three tier this is basically an ethane and this is this is a single sigma bond in which it can rotate right so this is one way to have a seahorse position but the other way is also where you can have it like this right so what has happened is this entire thing has rotated now if you really see because of this rotation the structure has changed three-dimensional structure has changed does it mean that the molecule has become different in this scenario no but I will show you structures where just simple change in the connectivity no not the connectivity is the simple change in orientation actually can lead to a completely different molecule here the molecule is incidentally not changed but what has happened is that this still are isomers because three-dimensionally at this point of time in space they are completely differently oriented so what are these isomers called in stereo isomerism the connectivity remains the same for example I have not changed any bonds I have not changed in any manner how both the carbons are connected to each other so all stereo isomers are those isomers where the molecule does not change I'm going to give you one more example for example I have carbon here I have a hydrogen I have CH3 and I have a double bond and I have a hydrogen and a CH3 in this scenario and this scenario where CS3 is here and hydrogen is here or hydrogen is here and a CS3 is again there is no change in the connectivity okay this car this CS3 attached to a carbon CS3 is also attached to a carbon the only change is in the orientation because there is no rotation between the double bonds these two molecules cannot be same at all okay they cannot be one and the same you know they are completely different molecules and in fact they give different kind of reactions as well the chemical reactivity is now you know mattered it is hampered okay so whenever you encounter same connectivity but different orientations is stereo isomerism okay now what are the different types of stereo isomerism so let's say this is all the branching of stereo isomerism sorry then then you will have two different types of stereo isomers one is what we call as conformational okay and the second is what we call as configurational okay configuration sorry let's understand from their words confirmation means that simply the you know the the bonds are rotating and their orientations have changed because of such rotations if they are allowed to align they will align okay so I can bring them back to then alignment if if if allowed rotation okay in configurational no matter of rotation or no matter of alignment will bring them back it's not possible okay they are bound to be different structurally although connectivity is still same okay now configure I'll explain what it really means okay configurational of two types one is geometric and second is optical optical okay now confirm conformational means that you know let's let's draw a Newman projection where I have I'm drawing not ethane this time but I will draw butane okay the CH3 hydrogen hydrogen and there is another hydrogen coming out here and maybe I'll put CH3 here okay and hydrogen so this is actually a butane where the the carbon at the back can rotate along the double along the single bond that it has with the first carbon this is the first carbon and there is a second carbon at the back okay carbon number two now the both of them can rotate and I can have multiple types of structure so as it rotates different structures are possible now I'm going to draw one more configuration which is a conformer where I have CH3 here and at the back the CH3 at the back also has come in here these are the hydrogens these are the hydrogens again and hydrogen and again and hydrogen here now please note both the CS3s are so close to each other that the repulsion in this scenario is going to be maximum and this is going to be the most unstable conformer that is possible this kind of unstable conformers are called as eclipsed eclipsed okay whenever you have conformers that are furthest apart okay so for example in this scenario I will have okay a methyl group here a hydrogen group here a hydrogen here and the furthest is going to be here okay the methyl group is exactly opposite and it is at the center of the 120 degrees that we have here right this is the most stable conformer conformer possible and this is called as staggered conformers okay staggered and anything in between anything in between for example methyl is here and methyl is is any at any other place it is called as Gaussian conformers okay Gaussian conformers now the point is that this methyl can also be eclipsed with hydrogen for example in this scenario this is very close to eclipse but not exactly eclipsed but let's say just behind the hydrogen there was a methyl then it was called as partially eclipsed conformers partially eclipsed okay because in that scenario also the repulsion is going to be maximum and the repulsion is going to be the least in this scenario even if methyl would have been here which is a staggered position the repulsion is going to be higher than the state okay so you will always be able to understand that where the repulsions lie and how strong the repulsion is in such manner okay now these are all geometrical conformers let's look at oh sorry these are all conformational isomers now let's look at configurational now remember I said that in conformational isomers you are able to get back any conformer from any any other conformer right because you simply need to turn the bonds but in configurational your structure is fixed you cannot turn the bonds anymore right but your connectivity still remains the same now let's look at an example for example in geometrical conformers you have these molecules like alkenes right I have a methyl and I have a hydrogen I have a methyl and I have a hydrogen now we all know that this is actually called as cis 2 butene right now why is the cis 2 butene is because remember this is the first type of geometrical isomerism is cis trans cis trans okay the next type of geometrical isomerism is what we call as ez isomerism now let's understand now look no matter what I do if I want to get this kind of a structure where here there is a hydrogen and here there is a methyl you know a ch3 group hey me means methyl group huh so don't get confused what am I writing me me all the time me me simply means ch3 okay so no matter how much I turn this I am never going to get this kind of sorry it has to be on the opposite side so this will be followed but this will not be okay yeah this will not be okay so they both are not possible now please note that when you have same at a same molecule or group of molecules then we use cis trans configuration but when you have different groups for example I have carbon double bond carbon and I have chlorine and I have bromine and let's say I have ch3 and I have hydrogen and this can also be related to let's say I have a hydrogen here and I have a bromine and I have a chlorine and I have a ch3 these two are isomers because both of them are one two sorry this is two three so these are two comma three two chloro sorry I'll write it completely once again yeah so this will be three bromo two chloro but two in okay both of these molecules are this please note if I draw a molecule which is something like this where I have cl and br okay and ch3 and edge they both are not even they are absolutely not configurational isomers they are basically position isomers is it oh wait it's not but it's prop it's prop my bad sorry it's prop okay so they are not even they are not even stereo isomers they are not stereo isomers now you are in the category of chain isomers because the bromine has shifted its position this molecule is in fact called as you know this will be one two three it will be three chloro three bromo okay uh uh two prop two in prop two in okay so it is a completely different molecule than this one so yeah tell me now if the ch3 was replaced by h then would it be a geometrical isomers if this ch3 was replaced by h yes would it be a geometrical isomers then of whom of whom uh like lower compounds yeah the lower compounds no because the lower compounds are all propenes the upper one will like all the lower compounds the ch3 was replaced by an edge if all the lower compounds the ch3 was replaced by h uh it will still not be because you're the chlorine and bromine are on two different carbons you're the chlorine and bromine are on the same carbon so if all the ch3's would have been replaced this would have been three chloro three bromo uh one uh three chloro three bromo ethene okay and this would have been one chloro not three sorry one chloro one bromo ethene and this would have been one chloro two bromo ethene one chloro two bromo ethene so they would still not have been uh you know stereoisomers forget about being geometrical isomers they will not even have been stereoisomers what about the ones below like only the two compounds below yes these two are because if you name both of these compounds both of these compounds have the same name so how do i differentiate between these two compounds and that is where geometrical isomerism nomenclature comes in get my point yes sir yeah so yes this is not yeah perfect so this is not even a isomer okay this is not even an isomer these two are isomers of each other now let's understand in cis and trans i had both of them methyl now how do we deal with uh the the uh groups which are unsymmetric in this scenario priority of the groups is considered and how is priority considered it is considered with atomic number okay now in atomic number carbon is the first priority okay after that you will have chlorine chlorine sorry hydrogen will be the first priority i'm sorry hydrogen will be the first priority because it's the smallest i mean you have to start with descending you have to start with descending so bromine is first in fact this will be chlorine second then you will have carbon third and hydrogen fourth okay now in this scenario on this side the higher priority is given to chlorine so this is the group you just mark a dot in this scenario higher probability is going to bromine so you make a dot here in this scenario higher is chlorine and higher is bromine if both the hires if both the hires are on the same side if both the hires are on the same side it is called as z isomer okay so this will be a z dash 3 bromo 2 chloro prop 2 in if both are them are on the opposite side it is called as the e please remember that z looks as if they are on the opposite side you know because z looks as if they are on the opposite side but that is not the case z is said to be for the same side and e is said to be for the opposite side so how did we name this cis and trans naming is very very easy because you know if you have both of them on the opposite side it is a trans and if you have both of them similar ones on this same side it is a cis please note in cis and trans the functional group or the the substituent groups are are the same you know where you are comparing here the substituent groups are different there might be two similar and one different that is also will be an easy configuration that will not be a cis trans whenever you have different you simply name them by the priority how is the priority decided the priority is decided by increasing atomic number so higher the atomic number higher the priority so bromine is higher than chlorine now on this side on the house on the house on this side bromine is more important than hydrogen and your chlorine is more important than methyl and both the important are on the same side so if they are on the same side we call it as z and if they are on the opposite side we call it as e is everyone clear with this are you clear yes sir Sundar did you get it yes sir perfect okay good now this is the third now let's let's try and see one more example let's see how many of you are able to do this let me do this okay c double bond c c o o h c h o hydrogen not hydrogen let me have this as chlorine and chlorine okay this and okay you name this let's just name this compound let's see just give me the en z you don't need to take the carbonic acid and the c h o name because then you know it will take time for you guys just tell me whether it is an en z it's a z no it's a z sure yes sir yes sir okay now tell me between c o h and c h o who will have the larger priority right now please note in this scenario the first carbon both of them are carbon carbon and therefore their atomic number is same in the scenario that you have their atomic number same you go to the next connectivity okay o h and here you have c double bond o h now since both of these carbons have the same connectivity or same order i go and check its next oxygen so both of them are having oxygen so doesn't matter now here i go and i have another oxygen now this oxygen has a higher atomic number than hydrogen here carbon is connected to hydrogen here so this will have a larger priority so the priorities go like this this is one this is two this is three and then this is four okay so the priority now in this scenario between these two the priority is maximum here now someone might say can this be one and this be two fine no problem both of them are acceptable okay so in this scenario both of them are actually on the same side and therefore this is a z at z molecule okay now the last one is what we call as anti and sin anti and sin configurations okay one second now okay now now the anti and sin are referred to when you do not have you know all the four groups matched okay you have only two or even one okay for example let's say we have a diazo molecule okay something like this you have diazo and you have a c6h5 and you have a c6h5 okay now please note that the nitrogen here is still sp2 hybridized because its lone pair is sitting here and here it will have a lone pair okay but as a molecule will not be able to see the lone pair we'll simply see one molecule like this and the same molecule can also exist like this okay where you have c6h5 on one side and c6h5 on the other side okay now in this scenario the bond strain this will be much larger this will be a much comfortable molecule because c6h5 are much farther apart right now in this in this case of course the c6h5 are given a larger priority now since these two are on the same side this is called as a sin this is called as a sin diazo molecule and this will be an anti diazo molecule okay so a sin and anti are used when you don't have all the functional groups but some somewhat something has taken out taken away by lone pairs and therefore there is a problem okay and and this such scenarios you will find that your sin and anti is the nomenclature that you'll use okay so that's that's one okay now so that that closes geometrical isomerisms so there are three types of geometrical isomerisms and let's go to optical okay optical isomerism now for optical isomerism the most important thing is to have what we call as a chiral center okay or a chiral carbon atom what do you mean by chiral carbon atom chiral carbon atom means something that is attached to three different sorry four different groups okay anyone any carbon atom that is attached to four different groups is called as a chiral carbon atom now what does the chiral carbon atom do basically you know there is a plane of polarized light everyone knows that the you know plane polarized right so whenever light moves it has vibrations in all the directions okay now if you make this light go through a polarizer which is nothing but like a slit it actually obstructs all the vibrations in these directions and only one vibration comes out after it okay so this is a vibration or this is the plane in which the vibrations are happening of the you know of the light now if this plane is suppose the plane is we are looking at the plane then this is how the plane will look like for us if this plane is passed through molecules this plane this light rotates either to the right or it rotates to the left if it rotates to the right then we call it as an r compound or what we call it as a dextro rotatory dextro means right and if it is rotating to the left we call it as a l you know a d compound or what we call it as a levio rotatory okay levio i think it is lea levio rotatory and this is a dextro rotatory okay so levio and dextro so these are the you know these are the properties shown by this one and how do we decide whether it is a dextro or levio rotatory basically what you do is you know you again do the same priority with atomic numbers right you say this is one this is two this is three okay and let's say the molecule was given to us like this okay that b is coming out and c is going in okay and this is fourth then what do you do whomsoever is the least priority that is the fourth priority you take it back and you look from the side opposite to it if you look from the side opposite to it and if i turn this d at the back you will realize that a will come at the top first b will go to this side okay that is second and c will come at the bottom this is third and d will be here at the center okay because it has gone back now what do you do you go from one to three in the you know you go from one to three now if you go in the anti-clockwise if you go in anti-clockwise direction then it is called as s s configuration okay and it is actually a levio rotatory okay s configuration or levio rotatory if you're going in the right direction you will you will call it as an r configuration or it will be a dextro rotatory okay now whether r always is extra and s always is levio not necessary how they rotate depends on the molecules but r means that the priority definitely is in the right is in the clockwise direction and s means that the priority definitely is in the anti-clockwise direction so these two are definitely very important right so this is a quick thing on optical activity there are three more definitions that i'll quickly run through one is what we what are inanchomers okay inanchomers now inanchomers are those compounds that are mirror images of each other mirror images but they are non super imposible non super imposible okay so which means that if you put those molecules on each other then you will not be able to match them let me give you a example of inanchomers as you know as some inanchomer inanchomer examples okay now apart from molecules i'll show you some some inanchomers which are inanchomer cars example cars maybe uh no so inanchomers i'm not non super imposible mirror images no one second some example hand is a very good example but i want to show you something else maybe a screw or something okay forget it okay let's look at this okay but look at this object you know if this and its mirror image if you put they can be super imposed but if you look at the right hand if you try to super impose them your thumbs will not match okay so this is the mirror image of your left hand which is the right hand and if you try to super impose them your thumbs will not match so whenever you have a non super imposible mirror images with with turning or without turning them uh you know you will realize that they are called as inanchomers now uh compounds which have the same configuration everything is same but they are not mirror images at all are called as diastereomers so mirror images but non super imposible inanchomers mirror images which are super imposible are nothing but mirror images okay super imposible mirror image there is no name for that diastereomers are those steve steveomers okay i might be mad this might not be there diastereomers are those compounds which are they are not mirror images itself okay they are not mirror images at all of each other okay and what is a racemixer a racemixer means that both the you know inanchomers are present in 50 50 percent okay now what happens in uh inanchomers one image is rotating it to the right the second one is rotating it to the left okay when you take 50 50 percent of them although the light gets rotated the end effect of the rotation of the light is zero okay there is nothing that will come out as a rotation okay so that's a racemixer and what is a mesocompound a mesocompound is when the you know both the inanchomers are present in the same molecule now when does the mesocompound happen whenever you have a plane of symmetry that can go through a molecule okay let's say this is a molecule and there is another molecule so a plane of symmetry means that the mirror image is happening within the molecule itself okay so for example i have a a b c here okay some groups and here again i have a a b c so there is a plane of symmetry that goes through the molecule itself although if you look at this carbon for this carbon a b and c and this carbon are completely different groups because this carbon is actually d for for for the carbon here okay this carbon is a chiral carbon but at the same point of time all of these groups have a mirror image at the bottom so although being a chiral chiral carbon this molecule will not show any optical activity because the upper portion if it is rotating to the left the lower one will rotate it to the right and it will nullify so mesocompounds are those compounds which have chiral centers but at the same time there is at least one plane of symmetry that can pass through the molecule which will actually neutralize all the optical property that the molecule can show okay now i'm just gonna pause here for a minute okay and i want you guys also to really take some breath firstly you know let's talk for a minute yeah are you all guys connecting yes optical activity too much to taken no so not really sir yeah are you able to recall all your 11 standard stuff whenever we're doing this yes okay there are three very major topics that i want to do in organic chemistry which are pending which is all the uh you know uh inductive uh electromagnetic effects on all of this the second is sn1 sn2 and the third is acidity and basicity of all the reagents but these three topics are going to take another probably one and a half hour okay so uh what i also feel is that maybe i can actually uh do amines and uh you know the uh what is it called the the second one uh coordination compounds a bit maybe in the next hour or so if that's okay with you guys what do you guys think so you can continue with the chapter are you sure sundar do you are you okay with that okay with that yes sir uh i just had few doubts i'll clarify later okay uh what do you uh kevin what do you think do you want amines i am okay yeah but this is not uh relevant to you uh for the upcoming exam so are you okay with that i'm against it yes okay so it's exactly 621 in the watch that i see here let's have a quick five minute break and be back at 625 you know or 626 is it okay oh yes sir yeah have a quick five minute break and we'll be we'll i'll see you again here keep keep i am keeping all of this on and even the youtube on we'll meet at 626 yeah this perfect see you bye yeah hi guys you're all there sorry got a bit late so so sundar is there yes sir oh good delay is also here akshath yes sir akshath is also very nice kevin kevin has run out it seems kevin um so uh tell me is it possible for you to leave early i have a pre-bored exam in tomorrow so that's why do you want to do till 7 15 or 7 or 7 akshath if i ask you 645 you'll say 645 no no sir i haven't done anything no i understand we can do it by 7 don't worry yeah we'll finish by 7 is it okay other guys anyways these online classes are very concentrated so what we actually cover in probably two hours we'll never cover so much in three hours and in the physical ones so you know the amount of content that we are doing is is is well enough yeah but i'll also do something that is going to help you directly in your exam so akshath we'll we'll do it in 7 is it okay yes sir so okay other guys is it okay yes sir and see now most of our classes now are oriented towards uh individual growth yeah see we have finished the syllabus now it's the month of no December that's gonna come up December is like you have your first exam in j e last time i gave you all the inputs as to how you can approach your j e right and what are the skills necessary etc so most of these classes that that we will be having from your on is going to be more focused on individual growths you know so don't don't depend at the same time don't mess out also get as much as possible if you see the amount of content that we do is quite deep and concentrated these will refresh a lot of things that you might have missed out last year and will help you you know have clarity in your concepts okay good so now let's go to uh firstly i'll talk about the effects different type of effects uh you know so let me see yeah now uh there uh basically you know all of these uh uh there are there are multiple types of thing uh you know that we have to understand firstly let's understand how many types of bond rickages are there okay so types of uh bond what is called as cleavage bond cleavage so basically you have two two different types one is uh homolytic and second is uh heterolytic okay now homolytic means uh that heterolytic or heterolysis okay uh basically now uh homolysis means that uh basically you have let's say an atom A and A which is hearing two electrons the electrons are given out as A dot and A dot A dot plus A dot right now in your school days or now though you guys are at the end of the exam so you must be knowing these are called as radicals in in the school days we used to call even ions as radicals like A minus as a radical but the the true definition of radical is when you have nascent the items that are not completely filled electro updates in the outermost shell and so these are radicals that you get by a homolytic cleavage okay a heterolytic cleavage is when you have A and B and both these electrons are taken by one guy and the other guy is left alone so you end up getting A plus plus B minus okay now when the when is the possibility for heterolytic cleavage when the electrolytic difference is very high okay and when they are of the same difference or exactly the same atoms uh then you will have a uh homolytic yeah so in electro negative difference is very high uh so an example would be HCL right correct HCL uh you know even H2O for that matter uh if I have to give any other example I might also give MGCL to NACL to all of that right now if you look at CO2 which are very close C C double bond O uh you know double bond O okay when you have CO2 uh now in this scenario you will find that uh the having a heterolytic cleavage is also going to be difficult and having a homolytic cleavage is also going to be difficult why because the electronic difference is not that high okay so uh but but if we have to have a heterolytic cleavage it will obviously be C4 plus and O2 minus and O2 minus okay so that's that's the one but uh very rare very rare now so that is homolytic heterolytic these are types of bond cleavage uh homolytic cleavage leads to radicals and therefore radical mechanism is preferred if you know chlorination is basically a radical mechanism now the second type of uh the second type of uh you know reagents are what we call as electrophiles and nucleophiles okay so these are types of reagents so what do you mean by uh let's let's see yeah so one second you have a electrophile and you have a nucleophile okay now electrophile means electron loving okay so obviously it has to have a positive charge or it it has to have an electron deficiency okay deficiency now what does have what what has a positive charge let's say NA plus okay CA2 plus all of these have positive charge what is an electron deficient molecule for example ALCl3 okay BF3 these are all electron deficient molecules ideally aluminum being a metal should give three electrons and form a uh ionic bond with chlorine and if it gives three electrons ideally it should be able to reach uh some kind of stability in octates or half half orbitals in boron boron for for example boron definitely is a three uh there are three electrons in the outer most shell it should give these three electrons and form an octate which is which is similar to helium's configuration but boron does not form an ionic bond it actually forms a covalent bond with chlorine and since it forms chlorine bonds there are three atoms from boron that actually are being shared with three sorry three electrons from boron that are actually shared with three electrons from chlorine and you will realize that it has no more electrons left for forming any more bonds and yet its octate is not completed that's six electrons in the outer most shell and therefore it is an electron deficient hungry molecule that keeps on digging for electrons all the while now there is a nucleophile nucleophile basically means nucleus loving okay and nucleus loving means basically positive charge loving so you will have these as negative ions or negative molecule negative uh multi atom ions okay or you will have an electron rich molecule okay so what do you mean by negative ions you have cl minus you have i minus you have OH minus all of those and what is a negative rich molecule basically NH3 where you have a lone pair H2O where you have two lone pairs okay so and so forth so electrophile and nucleophile are two types of reagents that are involved in mechanisms had homolytic and hydrolytic are the different types of bond fission that happens then there are four types of effects okay that happen okay now what are those effects the first effect that happens is uh inductive effect okay so what is an inductive effect inductive effect are the effects that are transferred through sigma bonds so let's say I have carbon chlorine uh and I have a let's say uh let me take this as uh magnesium okay and chlorine here now now chlorine being more electronective than carbon the sigma but this these are all sigma bonds okay so this is mostly a ionic bond so but if you the covalency character if we have to consider it would be a sigma bond then uh the chlorine is the one who is going to pull the electrons towards itself okay and therefore there is going to be a delta minus here and delta plus here whereas magnesium is going to give the electrons and therefore there is going to be a delta plus here and delta minus given to delta plus okay so carbon will have some kind of polarity which is in between plus and minus but mostly it will be a delta plus why because chlorine will take out electrons uh so much more than what magnesium can give okay so it is the carbon is net going to have a charge that is delta plus maybe delta delta plus two deltas means smaller positive charge this pulling of electrons within the sigma bond is called as inductive effect pulling is called as negative inductive effect and giving is called as a positive inductive effect so chlorine here is showing a negative inductive effect whereas magnesium is showing a positive inductive effect please note inductive effects are permanent in nature why it means that as the bond is formed this pull is going to remain in the bond forever you know till the bond is not broken okay so they are permanent effects the second type of effect is what we call as electromagnetic effects now electromagnetic effect is something that happens because of pi electrons so in yeah go on sir in the inductive effect uh example which you've given wouldn't the chlorine which is attached to magnesium also take electron yes the chlorine that's right so the chlorine is also going to take electrons but at the same time we are only looking at the uh different um uh you know uh effect that is happening on the carbon okay so if you if you want to look at so firstly you see magnesium and chlorine is going to be a highly ionic bond so if you if you extend the same logic of positive and negative inductive effect these two electrons will be completely taken by the chlorine and magnesium will be completely giving out the electrons so there is no there is there is basically uh no more uh uh availability of a sigma bond itself okay because there is a complete transfer of electrons so sigma bonds itself will not lie so we do not talk about negative and positive inductive effects in ionic bonds we talk about negative and positive effect in covalent bonds so instead in fact even talking between mg and cl is slightly less relevant than talking it between chlorine and uh and carbon because chlorine carbon is a perfectly covalent bond magnesium and carbon still has less number of covalency and more number of ionic character getting me uh yes sir okay now electromagnetic effect is when pi electrons are involved and uh uh you know uh that is that is the one that actually is for example let's say we have an alkene okay now in this alkene uh you have uh uh uh you know a hydrogen coming up okay so these two pi electrons are going to attack the hydrogen and take them with themselves to give you a carbon okay which has this structure and a carbon which has this plus a hydrogen here and with this carbon getting a plus now since the pi electrons are the ones who attacked the h plus uh this is going to be uh uh you know this is a positive electromagnetic effect okay so the pi electrons were given so this is a positive electromagnetic effect okay uh now please note that this electromagnetic effect is actually a temporary effect why because this happens only in the presence of uh an external reagent it is not happening in the presence of uh you know it doesn't happen by itself okay uh so therefore it is um uh it is only under the influence of uh external guys okay now now uh let's talk about the the same kind of effect but uh in a negative sense so let's say I have carbon and now I have a cn minus okay so this cn minus actually goes and attacks this carbon uh to give uh electrons so what is going to happen is you end up getting the same structure uh okay but instead of h you got here cn and this will be a minus now since the double bond the pi electrons move to carbon here the pi electrons moved here uh this is called as a negative electromagnetic effect because the pi electrons were withdrawn the pi electrons were not given the pi electrons were withdrawn by the carbon so this is a negative electromagnetic effect shown in the presence of cn minus electrons so electromagnetic effect is pi electrons moving they are temporary they are only under the influence of external reagents and uh and there is positive and negative electromagnetic effect the third one is what we call as mesomeric effect okay now mesomeric effect is an extension of electromagnetic effect but it happens in in the presence of conjugated pairs only so for example you have a carbon you have another carbon you have another carbon you have another carbon you have a double bond here you have a double bond here and let's say you have a configuration like this okay and hydrogen and hydrogen here now under the influence of an external guy or otherwise okay uh you will realize that these two are these electrons can be shifted okay to give you something that is carbon c double bond c so this will be a plus and carbon this will be a minus okay so since the electrons were shown thrown off by the uh by this carbon this carbon is actually showing a positive mesomeric effect and this is the one that is showing a negative mesomeric effect okay now please know what is the difference between electromagnetic and mesomeric electromagnetic for any so mesomeric you can see is composed of multiple electromagnetic effects okay having said this electromagnetic is generally under the external uh the reagent but mesomeric can happen even without an external reagent it's it's like within the molecule itself okay by itself now mesomeric is very close to what we call as resonance in fact mesomeric sometimes is alternatively also called as resonance for example let's look at benzene okay now in benzene you have all of these uh bonds and let's say you have a chlorine attached okay now chlorine has three lone pairs now this can go in here and then the bonds can start shifting okay so you end up getting a molecule which is something like this this is a cl plus with a double bond here and this double bond is now going to shift here minus okay and you will have this molecule now this minus sign is going to come to this bond and this is going to get into the carbon okay so you end up getting the next structure which is something like this a double bond cl plus and you have a double bond here and this is now going to get a minus and a double bond here and so and so forth you can keep on writing right so now we all know that these are the resonance structures that we have drawn all these are actually mesomeric effects uh why they are mesomeric effects because they are in a conjugated system and multiple pi bonds are moving also the pi bonds are not moving under an external influence of a reagent and therefore these are mesomeric effects and mesomeric effects also is sometimes called as resonance please note that resonance means that the permanent delocalization is already present which means that in for example in benzene the benzene thing we draw it like this is because that there is a permanent delocalization within the molecule okay and therefore benzene is a resonated thing mesomeric effects there is a permanence okay in mesomeric effect there is a permanence so in electromagnetic effect there is no kind of permanence resonance also are permanent effects okay so these are all the four types of mechanisms so we have seen two types of bond breakage we have seen three uh we have seen uh two types of reagents we have also seen uh you know four types of effects now now we are going to see what are uh different types of reactions okay there is one more that I will actually speak about which is hyper conjugation which is also important okay so hyper conjugation means uh you know the neighboring hydrogen is uh given out so it's it's very much like let me write this fifth one hyper conjugation okay now let's say you have a carbon carbon and you have a double bond of carbon and now you have a hydrogen and then hydrogen okay now sometimes this double bond moves to this carbon and it actually takes out the sigma bond so this was a sigma bond this is also a sigma bond there this can be another sigma bond and this is a pi electron so the pi electron is taken uh under the influence of an external reagent or otherwise taking out a sigma bond in conjugation okay taking out a sigma one earlier we were taking out only pi bonds so this actually leaves us to form a double bond here this carbon this is a c minus and you end up getting an h plus here okay now this h plus that is taken out if there is a possibility it will go and attach to the next carbon atom possible okay to the next carbon atom possible here and you you end up getting a shift you end up getting a shift okay c h so the carbon that was let's say this was a star the star carbon has now got a double bond everything else remaining the same okay it has all this hydrogen etcetera remaining the same and the one that was hashed is now getting a hydrogen okay now attachment of the hydrogen is not considered as a hyper hyper conjugation but this removal of hydrogen only this time this is hyper conjugation okay and this is not one so that's uh so what is hyper conjugation hyper conjugation is taking out an alpha carbon okay so from this if this is a double bond this is the functional group this is the alpha carbon so taking out the hydrogen from the alpha carbon because of movement of pi electrons and the breakage of sigma bond of the molecule hyper conjugation exists now you can you know do all kinds of logic you know for example if there would be cs3 cs3 molecules here cs3 here cs3 here then there will be never a hyper conjugation why because it is very difficult to break a cs3c sigma bond but if there are hydrogens hyper conjugation will be very prominent right now there are multiple factors that are necessary for hyper conjugation you know if you get time I would recommend that you quickly go through one of your 11 standard chapters where all of these effects have been very clearly defined okay now now having said this this is the number of effects that are possible now how many types of carbon atoms are formed in reactions there are three types types of carbon atoms carbon ions actually okay the first one is carbocation okay now carbocation means c plus okay now if c plus has let's say another cs3 cs3 and cs3 attached to it then all of these will show positive inductive effect and c plus will be very stabilized okay so therefore carbocation's three degrees are more stable than two degrees more stable than one degree always remember the second type of molecules that is ions that is formed is carbo carbanion which is nothing but c minus okay now in c minus if you have three degree then all of them will be giving okay and c minus will get even more comfortable so in c minus you have one degree less than two degree sorry you have one degree more greater than two degree greater than three degrees I'm talking about the stabilities okay guys stabilities three degrees so this is the order of stability stability order and this is the order of stability okay right so this is the order of stability for carbanion now the third thing is what we call as radicals okay so radicals means you have c dot okay now remember whenever you have a radical generally the inner tendency of the atoms is shown now the inner tendency of the atom is carbocation that is that is moving pushing and since it is an electropositive which is showing a positive inductive effect radicals have the same kind of an order that is there of carbo cation okay so because the inner tendencies are more revealed so therefore you get three degree greater than two degree greater than one degree so three degree carbo carban radical is more stable than two degree and one degree having said this carbon radicals of three degree will be much more stable than carbon radical carbo cation why because this does not have any electrons this at least has one electron here both the electrons are lost here only one electron is lost here both the electrons are present therefore it becomes very highly unstable right so between radicals and carbo cation radicals are more stable than carbo cation okay so that's that's another example now these are these are all types of different types of carbon molecules formed so we have seen looks so many things firstly we saw what are the different types of bond breakage then we saw what are the different types of reagents third we saw what are the different types of effects fourth we saw what are the different types of carbon ions that are formed carbon and all of them and then we saw what are their stability is okay now the next thing that yeah there is one more that we I'll just quickly look at you know tell you and this is just very special kind and therefore we don't speak about them much but they are called as carbines you know and what are carbines they are carbon atoms with two atoms okay and only two bonds so there are two two electrons and two two bonds okay so there you'll have a RR here and this is actually an sp2 hybridized you know carbon atom and most of these carbines are generally in diazo compounds okay for example you have CH2N2 okay so this is diazomethane if you really make you know light pass through it that is HMO you'll realize that this actually gives you a carbine and a carbine radical you know you can call it as a you can just say simply carbine okay carbine plus you will get N2 so these carbines are mostly you know found when they are attached to nitrogen especially like a diazo molecule okay these carbines are very very reactive very unstable very reactive because now you have taken out both the electrons from this if you look at CO now CO actually has a double bond this carbon also can exhibit a carbine property very well generally the CO structure is with a double bond and a coordinate covalent bond given by oxygen to carbon that is our CO molecule is stabilized but the breaking of carbon coordinate covalent bond is very easy and therefore you can also get a carbine carbon yield which can actually go and attach okay that's carbines now like carbines you have nitrenes also so nitrenes is nothing but you know nitrogen with just a nitrogen atom you know basically with two lone pairs with it okay now it can be attached to so in here we have broken two bonds here nitrogen also two bonds are broken and therefore there are two lone pairs on nitrogen okay so this is also a nitrene molecule okay another type of reagent that is very well used okay for example Hoffman bromamide reaction HBR if you remember HBR reaction it is the nitrene molecule atom that is used carbines are used in Riemann and Hoffman carbamide reaction or yeah Riemann I think you would remember if you remember then you know carbines are very well used there okay and the last one would be arines arines actually and arines means nothing but you know benzene like molecule with a triple bond okay with a triple bond these are arines again these arines have this this portion of the arines is extremely reactive you know very very highly active shows electromagnetic effect extremely fast and reactions are possible okay so these are these are the different types of reactions the last thing that will come up is what are the different types of reactions that will happen okay now obviously there are three types of reactions addition second elimination and third substitution guys are you all there a quick hi yes sir yes sir yeah it's all on good now addition elimination and substitution now look all these addition reactions all of these in fact you know I'm going to say for everyone together okay because I don't want to do it for all of them all of them actually happen through either a nucleophile or an electrophile I am going to give only a couple of examples and you can extrapolate the same what is a nucleophilic addition for example look I have a C double bond C hydrogen hydrogen this and there is an H plus coming on right so H no H plus is a not H plus there is a C and minus coming in CN minus no CN minus needs is a nucleophile because it is negatively charged loves nucleus it goes and attacks carbon this bond shifts in the end you will end up getting a compound which is CN year and C double bond and then hydrogen year okay this is a nucleophilic addition because a CN and H was added but CN was the one who attacked and it was a nucleophile so it is a nucleophilic addition what is an electrophilic addition an electrophilic addition would be a hydrogen hydrogen H plus and H attack adding right H plus will attack the lone pair not H plus will not attack the lone pairs will attack the H plus other way around it's see whenever we draw these arrows always only electron movement is shown at a moment is not shown so these electrons are gone to H plus and you will end up getting an hydrogen hydrogen added on the alkene so this is a different reaction this is a different reaction so these are electrophilic and nucleophilic additions now both electrophilic and nucleophilic additions can happen in two ways okay one it can happen it its reactivity is proportional to only one molecule in which you call this as first order and it can be proportional to two molecules and you will call it as second order if it is the first order we generally call it as N1 if it is the second order you call it as N2 I'm just going to tell you how the first order reaction looks like if it is only proportional to the first order let me talk about an addition reaction okay so in this addition reaction let's say CN was the one who is going to attack the C double bond C okay now the breakage of this bond is very important and therefore the reactivity let's say is only dependent on this guy okay if it is dependent on this guy the reaction this bond will firstly break and you will end up getting CC and you'll end up having a C minus and and CN here okay here since the reactivity is only dependent on this reagent therefore it is a first order reaction but after this has formed H plus will come and you know attached to this carbon so it happens in two stages two stages so remember the first order reaction happens in two stages so whether it is AN1 or it is an EN1 or it is an SN1 SN1 all of them will happen in two stages whereas when it is an SN2 it means it is now if the CN minus is reacting with this so both of them are forming same so there is an H that will come from the other side so CN minus attacking this carbon and H attacking this carbon attaching to form CN and H both of them are going to happen in the same phase in the same manner in the same tempo in the same rate and therefore it is a second order reaction but it will be a one stage reaction one stage means only one step only one step required here there are two steps required okay so SN2 EN2 etc will all be a one step process okay so this is a nutshell of all how addition elimination substitution happens right now having said this the last type of property that I am going to talk about is the types of solvents okay now solvents are sometimes polar and they are non-polar okay now polar solvents implies they are basically water okay you can also have you know water is one then you can have maybe HCl liquid or you can have HF liquid all of those right all of those are polar solvents if you want to use any of those in fact these are acids you never use them as solvents but what can I think of another polar solvent maybe I should not mention this but polar solvent so H2O is a polar solvent you know just as simple as that okay now non-polar solvents could be like benzene okay any long chain alkene okay long chain alkene you can also have ethers okay ethers are highly reactive non-polar okay now whenever you have solvent which are polar then these solvents will obviously stabilize ions they will stabilize ions and since they will stabilize ions formation of ions is very easy since formation of ions is very easy it will undergo a two step process that firstly one ion will form and secondly the second ion will form and bring it therefore a higher polar one actually you know favors SN1 E1 A1 all of those you know they favor all of these mechanisms mechanisms okay there is a non-polar one which cannot stabilize ions everything has to happen simultaneously if ion is formed it will not be very happy so everything has to happen simultaneously therefore the reactivity is proportional to two molecules and therefore it is a one-stage process because everything is happening at the same time and you will end up getting most of the mechanisms as SN2 E2 you know A2 all of this when I say E2 it is elimination 2 whether nucleophilic or electrophilic all of those right now there is always a competition whether SN1 will happen or E2 will happen or even will happen right all of that depends on three things first how good is the leaving group how good is the leaving group if the leaving group is very good leaving group means what if for example in CH3 Cl I want to make this as CH3 OH okay so is Cl a good leaving group yes so if it is a good leaving group it will leave form Cl minus and CH3 plus then OH will come and attack since it is a good leaving group if I put this in water it will definitely leave and since it definitely leaves it will go through an SN1 reaction right so what is how good is the leaving group if the leaving group is bad then someone will have to kick it out and if someone is going to kick it out then there will be two molecules who will be involved in the reaction of kicking it out and it will be a one-stage process and it will go through SN2 so the first one is leaving group the second one is solvent what solvent are you in if you are in obviously polar solvents then ions are preferred and therefore two-stage process and it will happen okay the third thing is how how strong is the base okay base means am I using OH minus to take it out or am I using some other you know for example F minus or I minus I am using to kick it out so how strong is the base for example between HF and HI HI is a very strong base but stronger than HF so HI will be able to kick out chlorine much faster than F minus right so these are the three different categories that will define whether a particular mechanism will happen leaving group solvent and base these three will also define whether it will be a homolytic heterolytic or not for example if you are using a sunlight it will be a homolytic fission and you will go through a radical mechanism none of these SN1 SN2 E1 will happen it will all be a radical mechanism okay so maybe the fourth one that I can add here is a radical mechanism okay so a radical can happen it will never happen through a nucleophile an electrophile only these three will happen nucleophile a radical will happen through radicals okay so now this is a very very long topic you know I think and I could go on non but there is you know there's lots to take in yeah are you guys able to connect do you guys remember what we had done earlier in 11th etc do you guys remember all of that yes sir yes sir okay is this helping you home yes sir yes sir okay now okay now so you know because we are just at the end of the time we have almost finished 30 odd pages of writing today just a quick thing what is the syllabus that you have for your tests coming up so I'm going to stop the transmission here you know yeah