 Hello students who have known who are there please type in your name in the comment box please join the link guys I have shared on the group mark your attendance in the comment box all of you please hello Shreya, Samyukta, Ardra where are others guys please join fast solve the assignment that I have shared on solution chapter all of you have done that okay let join so guys today we are going to start a new chapter of inorganic chemistry and the chapter is coordination compound we are going to discuss this chapter today first of all you see what is the coordination compound like we know about the normal compounds we have that is NaCl, MgCl2 etc these are simple compounds okay and we have only one kind of bonding in this kind of compounds right the major difference between coordination compound and the simple compound is the type of bonding which is present in coordination compound okay coordination compound mainly there are two types of valency we have two types of bonding we can explain by different different theory but in the coordination compound we have two types of valencies okay so don't write it just now just just let me you know explain let me give you a brief idea of this chapter and what is this compound is all about in coordination compound there are two types of bond present or valency we have the first is primary valency and the second one the first one is primary valency and the second one is secondary valency right generally in this compounds we have one only one type of valency present okay hello Paras correct but in coordination compound we have two types of valency these coordination compounds have different properties also right properties in the term when we dissolve this into any solvent like water correct so what happens when we dissolve a coordination compound into water the way of dissolving these compounds into any solvent that is also different from the various simple compounds that we have okay and we have a huge application of this coordination compound in our day-to-day life first of all if I give you some examples like chlorophyll okay chlorophyll pound in plants this chlorophyll is a complex of magnesium okay mg complex complex of magnesium okay if you talk about hemoglobin right h a e hemoglobin these are the complex of iron iron complex which is very useful right blood hemoglobin is observing this found in blood chlorophyll is found in plants magnesium complex so with all these examples you can see this has a huge application in our day-to-day life also okay now the main thing is what here you have to understand before going into the classification of compounds suppose if I take one example of coordination compound which is k4 fe cn6 complex of iron k4 fe cn6 okay this is a coordination compound and we also call it as complex compound coordination compound or complex compound are same thing both are same thing correct okay now there are various terms involved in this particular type of compound that term we'll see okay but the major difference is what suppose if you have any simple compound like I said like I say we have NaCl one example I'm taking of simple compound NaCl when you dissolve this into water H2O it dissolves into two iron that is Na plus and Cl minus and those ions we call it as Na plus aqueous and Cl minus aqueous okay and what we say since this iron or this molecule dissolves completely into its ions so what we say that these simple compounds loses its identity into solution identity in solution losing identity means what it dissolves completely into its ions okay the ions from which they have formed it dissolves completely into those ions so NaCl is no longer exist is not existing in the solution it exists in the form of Na plus and Cl minus hence we say that they loses their identity completely I'm talking about normal compounds okay but these coordination compound if you dissolve this into water this also dissociates into its ion form but the dissociation is not complete okay like suppose this molecule dissociates in the form of this we'll get 4k plus and that another ion will be FeCN6 4 minus these are the two ions we get understood these are the two ions we get so what we observe here that this ion it won't dissociate in the form of k plus Fe plus CN6 CN minus this kind of dissociation won't be there but it dissociates in the forms of k plus and this complete thing negative charge of it okay so what happens here you see this part which is the complex part the you know the part or the you know which is written in this square bracket we call it as the complex part of this compound okay this is what this is the complex part so when you look at this ion complex part when you look at this ion the complex part does not dissolve it retains its identity in the solution okay because there is no Fe plus and Fe minus and Fe plus and CN minus present but this whole ion is present in which Fe CN bonding still exists in the solution okay so what we say the complex part retains its identity retain its identity even in the solution retains its identity even in the solution so this we call it as this is the major difference between a simple compound this is a simple compound and a complex compound or coordination compound this is the major difference simple compound dissociates completely loses its identity completely in the solution here the dissolution is not complete the complex part retains its identity even in the solution do you understand the basic difference between the coordination compound and this the simple compound if you understood these types CL are in the comment box quickly now coming back to the next point to understand this coordination compound we must require the concept that we already studied which is the concept of chemical bonding chemical bonding concept you must have concept of chemical bonding you should have you should have the concept of no orbital overlapping orbital overlapping or you should have the concept of hybridization these three things you must know to understand the bonding in complex compound or coordination compound okay so if you have any doubt into this please go through it after this class okay because today we are not going to use this but in the coming class obviously we'll use this concept to understand the bonding okay but again we'll discuss this into the class also okay now if I write down the classification of compounds like the basic understanding I have given you like what is the complex compound what is the coordination compound two types of bonding I said this k plus an fe this we call it as metals right this is this is metal and we also call it as the central metal atom cma is the abbreviation we are going to use for this term central metal atom okay that this term will use very frequently in this chapter central metal atom so whenever I say central metal atom write down cma okay this is metal and this cn minus it as attached with this metal and k plus also attached with this metal this cn minus will have a different kind of bonding with this metal k plus will have different kind of bonding with this metal that's why we say the bonding of k plus and fe is different cn minus and fe is different and hence we say two types of bonding we have which is nothing but the two types of valency we are seeing primary and secondary so we'll discuss this later okay we'll go into detail all these things later okay now you see the next thing we have to understand is the classification of compounds classification of compounds how the compounds are classified see there are mainly two types of compounds means the compounds are classified mainly into two categories first of all which is the first one is we call it as additional compound copy this down additional compound or we also call it as molecular compound additional or molecular compound the next one is simple compound simple compound simple simple compound like I already told you the examples of simple compounds are like NaCl, MgCl2 etc which dissociates completely these are simple compounds okay additional compound or molecular compound again this is also classified into two categories into two categories and these are the first one is double salt double salt and the second one is the coordination compound the coordination compound okay so double salt the example is what we'll see that examples of double salt additional or molecular compounds are those compounds which contains a high water molecule as in in the hydrated form for example you see the additional compounds examples of this you write down suppose if I write down the molecule like carnellite kcl.mgCl2.6H2 this is additional or molecular compound hydro water presents in the hydrated form the name of this compound is carnellite name is also important you must keep this in mind another example of additional compound we have morse salt which is nothing but FeSO4.nh42SO4.6H2O the name of this compound is morse salt right they won't ask this name in JEE but in the other you know state level exams like CT and all they ask these things also what is morse salt like that okay so name is also you must keep in mind okay one more compound we have which is not that much important but we also call it as potash alum or simply alum the formula is K2SO4 dot al2SO4 whole thrice dot 24H2O all these when water molecule present in hydrated form we call it as alum right these are additional compound got it additional compound like I said it is classified into two categories double salt and coordination compound double salts are what just point wise you write down these are the compounds which are stable in solid form stable in solid state actually stable in solid state but in water but in but in water it dissociates completely dissociates completely like for example you see if I am using this only one example I will write down KCl dot MgCl2 dot 6H2O if you dissolve this in water it dissociates completely and it forms various types of cations and anions K plus it forms it forms Mg2 plus it also forms 3Cl minus plus will have H2O as it is 6H2O you see all these dissociates completely into its iron we call it as double salt similar kind of nature of simple compounds also we have but it is not the hydrated form there is not a dot kind of structure we have any C-MgCl2 like that okay coordination compounds like I already discussed these are the compounds which does not dissociates completely one example you see K4 FeCN6 FeCN6 and when it dissolves in water it converts into 4K plus plus FeCN6 4 minus okay does not dissolve completely understood so for this chapter our more our you know more focus will be on this coordination compound that is what we are going to study in this chapter this is the brief idea of what all different different types of compounds we have our focus will be on coordination compound coordination compound and complex compound are the same thing did you write this can we move on let me know guys if you are done okay next page the definition of coordination compound write down the definition first write down to this these are the compounds these are the compounds which forms by these are the compounds forms by two or more two or more simplistic by sorry by the combination of by the combination of combination of two or more simple stable compounds simple stable compounds that retains their identity retains their identity in solid in solid as well as as in dissolved state in solid as well as in dissolved state now you see in this chapter we are going to use various different terms to understand this coordination compound okay so first of all we will see what all those terms we have that term we are going to understand with like one simple example and the example is say why I am taking k4 fe cn6 k4 fe cn6 now you see here the you know the part which is written the in the square bracket we call it as the complex part right this is the complex part and we also call it as complex part or coordination is fear okay this is the complex part and we also call it as coordination is fear is fear instead of sphere we also write it as coordination entity that is also same thing right so coordination is here coordination entity is the complex part and what is the nature of complex part complex part does not dissolve in solution means it retains identity in the dissolved state that we have already discussed retains identity in the dissolved state this is first term right the central metal atom is this okay this iron is the central metal atom this is central metal atom cma is the central metal atom this thing cn here we call it as ligands what is what is ligands that also we will see these are ligands okay and the iron which is present outside this square bracket we call it as ionization is fear it is ionization is fear or we also call it as counter ion both are same thing ionization is fear or counter ion understood what is ligand ligand is the electron pair donor ligands are electron pair donor did you finish this chapter in the school guys okay these are electron pair donor okay now this these are the few terms that we use for central metal atom ligand all these terms we'll use very often in this chapter okay so you must keep this in mind what is ligand what is central metal atom and all see like i said electron pair donor ligands are what electron pair donor so these ligands we have six ligand present here and all these six ligands donates pair of electrons not one single electron i'm talking about a pair of electron so one ligand donates one pair of electron to the metal okay so if the ligand is donating electron to the metal it means the metal has the ability to accommodate those electron pairs yes ligands are donating electron to the metal so metal must have the ability to accommodate those electrons correct and how the metal will accommodate those electrons for that metal must have vacant orbital present okay if the metal does not have vacant orbital present they won't be able to accept those electron pair which is donating by the ligands and hence the bond won't form correct that is why we say what that these kind of compounds which is coordination compound mainly forms by mainly forms by transition element right down partition compound mainly forms by mainly forms by transition element d block elements why transition because we know in d block elements there are vacant d orbital present so in those vacant d orbital of metal ligand can donate its pair of electron and the bond forms okay so this is the property of the ligand ligands are what ligands are the electron pair donors metals except electron pair from the ligands and hence generally we say what the coordination compound is mainly formed by the transition element since they have vacant d orbital since they have transition elements have vacant d orbital this is one thing okay another thing is what you see the complex part in this example k for fe cn6 this is positive charge if you find out the charge on the complex part the charge is negative right this is minus four on this complex part and this is plus one four plus four negative here so when the minus charge or negative charge present on the complex part the molecule is said to be complex anion okay so this molecule not that important name but i'm just giving you one small information here this molecule is known as complex anion because the complex part is negative so it is complex anion similarly we can have complex cation also and we can have complex cation complex anion both possibility we have all the three possibility basically we have the complex anion one example we have seen the another example you see for complex cation if i write down this molecule c o n h3 6 close bracket and then we have cl3 outside okay so now in this molecule you see cl minus we'll have here so minus three on this so here we have plus three and minus one on one chlorine atom so the complex part has positive charge and hence we call it as complex cation complex cation okay another example you see one more i'll write down suppose if i write down this molecule or c o n h3 6 c r c2o4 whole thrice so in this both cation and anionic part are complex so we call it as complex cation complex cation and complex anion so basically all three possibility we have in coordination compound we can have complex cation part complex anion part and both part can be complex as well okay if i take this example can you tell me this term ionization is pure coordination is pure ligand central metal atom can you tell me what is this cobalt here we have what is this cobalt here out of this term that we have discussed here anion is pure coordination is here ligand central metal atom what is this cobalt it is central metal atom right so this cobalt is the central metal atom what is n h3 what is n h3 what is n h3 right n h3 are ligand what is cl- what is cl- who is this m as cl- is the counter ion or ionization sphere okay counter ion or ionization sphere okay what is this part this square bracket the whole thing is what the whole thing is coordination sphere okay so understood the terminology ligand central metal atom ionization is pure coordination is pure or entity okay this you must remember now we will see one by one what is the definition of ligand we have and how the behavior of ligand right so next thing see guys one thing i'll tell you this is you know the only chapter in inorganic chemistry where you can apply some logic and you can understand the you know question there are a few things to memorize that you have to do but to solve the questions you can do it logically it's very important and every year in je they ask one question from this chapter and you never know what question they are going to ask because everywhere you can have possibly 10 to 12 different types of question possible okay out of all the concept that we will study in this chapter the isomerism is the most important part in this chapter we have isomerism in coordination compound okay that we'll discuss in the last but on the basis of this isomerism concept they ask question every year in je exam je exam or bidsat or any other exam ct need whatever you write okay so this chapter going to have one different questions from the chapter in the exam okay 10 to 12 different different types of questions possible so that's why it's very important to understand few things again you have to memorize but that i'll say around 10 to 15 percent only things you have to memorize rest you can do it by logic okay so next thing you write down the various terminology that we have seen that is ligand and all what is the definition of that the most important term we have here and that is ligand write down ligand definition is what it is a molecule ligands are molecule it is a molecule it can be an atom also molecule atom or iron which are able to which are able to donate electron pair take care of this thing i'm talking about electron pair not electron which are able to donate electron pair to the central metal atom electron pair to the central metal atom or iron central metal atom or iron these ligands it can be neutral it can be neutral it can be negatively charged or it can be positively charged all three possibilities we have here now you see one thing is very logical here since ligands donate a pair of electron to the metal so what we can say they are bonded with coordinate bond with the metal how the coordinate bond forms you know this coordinate bond how this how this coordinate bond forms let me know if you know this otherwise i'll explain it a bit you know what is the coordinate bond how it forms mass mass reply what is the coordinate bond okay one example i'll take off coordinate bond see coordinate bond what happens um suppose you have i'll take the example of n h 3 okay n s 3 has one lone pair of electron so n h h h and nitrogen has one lone pair on it so generally what happens the bond forms by the sharing of electrons one so here you see in this n s 3 here we have one bond of hydrogen and one bond of nitrogen sharing takes place this bond forms so each atom in the bonding state uh you know provides one electron to formation of bond correct here also you see one bond of hydrogen one bond of nitrogen one bond of hydrogen one bond of nitrogen so each of these atoms present in each bond contributes one electron in the bond but what happens suppose you have one h plus here right h plus here h plus means what this has one vacant s orbital so it has ability to accept a pair of electron correct and nitrogen has one lone pair available correct so what happens here this nitrogen has tendency to donate this lone pair of electron to this proton which is h plus right and what what happens here the bond forms between nitrogen and hydrogen and we say nitrogen has three bond which is covalent like this n h edge and the fourth bond between this nitrogen and hydrogen is a coordinate bond directed towards the atom which accepts electron so this bond is a coordinate bond right this bond is a coordinate bond so what happens in this the bond pair which is you know present in this bond it originates from the single atom that is nitrogen only all these bond pairs two bond pair of electron we have here this pair of electron is of nitrogen only but here in this bond you see one electron is of hydrogen one of nitrogen and that is same we are here also but in this bond the pair of electron which is present that originates from nitrogen itself there is no involve in like like the electron of hydrogen hydrogen does not involve in this bond formation correct so this bond we call it as coordinate bond this bond is coordinate bond or the other name of coordinate bond we also call it as dative bond dative bond got it point is coordinate bond forms when the bond pair of electron originates from the single atom the one atom this n is three since it is donating electron so here in this bonding state this nitrogen will have positive charge on it hydrogen accepts electron one positive charge it becomes neutral and will have and this is what we call it as NH4 plus ammonium ion NH4 plus got it so the point is this NH3 is electron pair donor we have this is donor and this is accepted did you understand this H plus is the acceptor NH3 is the donor understood correct so now the same situation we have here also and the situation is what ligands donate a pair of electron and metal accepts pair of electron correct ligand donates a pair of electron and metal accepts a pair of electron so you can replace this H plus by metal and you can replace this NH3 by ligand so what we can say what we can say the ligands with the central middle atom with the central metal atom by what kind of bond we have here what kind of bond by coordinate bond coordinate or dative bond the third thing is this the bond between the ligand and the metal is coordinate bond right this is one thing and second third thing is what ligands are electron pair donor and we know that donor electron pair donor are Lewis base electron pair acceptor are Lewis acid so what we can say here the ligands ligands act as a as a Lewis base but metal act as a act as a Lewis acid okay Lewis base and Lewis acid this question also they may ask you why because ligands are electron pair donor and metals are electron pair acceptor did you understand this now next thing we are going to understand here see don't write this one now just you look at it ligands are actually classified on two basis one is the charge on it charge on the ligand and other one is the basis of denticity right what is denticity we will discuss that but charge means what like I said ligands can be neutral can be positively charged can be negatively charged all three possibility we have so when we see the classification of ligands on the basis of charge we'll have three types of ligand possible negatively charged ligand positively charged ligand and neutrally these are the three things charge also you should know that what is a charge present on the ligand because later on we'll see we have to find out the oxidation number of metal in the given complex okay we need to find out the oxidation number of metal and to find out the oxidation number of metal you must have the information of the charge on the ligand whether it is negatively charged whether it is positively charged whether it is neutral all these information you should have then only then only you can find out the correct oxidation state of ligand that's why this is important denticity means what it is the number of electron pair accepted by a central metal atom from a particular ligand okay so one ligand if it can donate only one electron pair its denticity is one we have possibility that one ligand can donate more than one pair of electron also right so depending upon the number of electron pair one ligand can donate the classification of ligand we also have right if suppose ligand can donate only one pair of electron then its denticity will be one and we call it as its monodentate ligand okay denticity one monodentate ligand denticity two bidentate ligand denticity three tridentate ligand like that we have classification of ligands okay so do you understand the basis of classification of ligands one is on the basis of charge and other one is on the basis of denticity what is denticity it is a number of electron pair one ligand can donate if it is one denticity is one called monodentate ligand if it is two denticity is two called bidentate ligand and so on is it clear yes okay so next you write down the classification of ligands classification of ligands the first one the first basis is on the basis of charge write down on the basis of charge the first type we have here a is neutral ligand neutral ligand the charge on this type of ligand is what zero so on neutral ligand the charge is zero and you should know the examples of this kind the examples are we have H2O NH3 NO we can have C6 H6 etc okay CO also we can write one more example carbonyl group CO right you see since the ligands are electron pair donor so obviously what is the donor atom we have here in H2O can you tell me what is the donor atom in H2O which donates electron pair to the metal oxygen right because oxygen has lone pair of electron on it okay so hence oxygen donates pair of electron and with and yeah and with metal this oxygen is bonded not hydrogen similarly nitrogen has lone pair of electron so this is the donor atom here in this both can donate electron C6 H6 there is no lone pair on to it but this pi electron can take part into bonding pi electron of it we will discuss this later that also may form a coordinate bond pi electron of C6 H6 okay so we will discuss those later all these are neutral ligand because there is no charge present on it okay second type you see the the second type we have negative ligand again I am telling you this charge you must remember because later on we have to find out the oxidation state of metal for that the charge is required neutral ligand sorry negative ligand which has negative charge on it right so we have some negative charge on this ligand for example you see we can have halide ion as the negative ligand we can have NO2- nitrite ion SO42- right we can have CN- negative ligand we can have OH- negative ligand etc all these are negative ligand okay third one is positive ligand positive ligands are generally very less in number only one or two we have that we will see charge is positive plus charge we have on this ligand positive charge for example you see we have hydrazinium ion which is NH2 lone pair NH3 plus this is positive charge ligand nitrosonium ion NO plus this ion is nitrosonium very rarely we will use this but you write it down and this one is hydrazinium NH2- NH2 is hydrazine from that it is hydrazinium charge is positive on it so on the basis of charge we have seen the classification of ligand the next one is on the basis of density classification on the basis of density okay so first of all write down the definition of density what is density what is density definition you write down it is the number of electron pair it is the number of electron pair accepted by by a central metal atom or ion or ion from a particular ligand from a particular ligand is known as is known as the density of that ligand in the given complex number of electron pair accepted by the metal that we have to see it's the density okay on the basis of density the ligands are classified into following categories see that the first type of ligand we have here is monodentate ligand what is monodentate ligand what is monodentate ligand density one okay yes monodentate ligand write down the density of this ligand is one i'll write down the examples here the examples of monodentate ligand are h2o it can be neutral it can be positive it can be negative anything h2o ns3 cn minus f minus cl minus dr minus x minus actually c o we have no 2 minus o h minus or no etc all these are monodentate ligand right remember here this nitrogen this oxygen both can donate electron this nitrogen this oxygen both can donate electron but at a given at a time only one atom attached with the metal that's why the density of these ligands is always one monodentate ligand second one i write down bidentate ligand bidentate we also call it as didentate bidentate ligand write down these other ligands whose denticity is two denticity is two example you see i'll write down the next page all of you have done this can i go to the next page the first example we have of bidentate ligand is first example these examples are also important even if more than one lone pair is it donates only one pair yes one atom can donate maximum one pair of electron not more than that otherwise that will be uh unstable very unstable okay one single atom present in a lone in a ligand cannot donate more than one pair of electron correct now you see the first example here we have is ethylene diamine ethylene diamine now you try to understand this carefully the first thing is the structure of this ethylene diamine okay and the structure will draw and it's a symbol also you should know right means ethylene diamine can be written as en also so in the exam or question you'll have this symbol written they won't write all these entire name they write this en simply en means ethylene diamine right so this symbol also you have to memorize the structure you can understand easily structure will be this ethylene diamine so c h2 c h2 ethylene diamine we have so two n h2 group attached here okay so i'm drawing the structure here also this two nitrogen atom donates pair of electron to the metal okay donor atoms are nitrogen here second example you see b oxalate oxalate o x the symbol is o x okay the structure is this c double bond o c double bond o o minus c double bond o o minus and this is the donor atom donor atom is these oxyces okay c glycinate glycinate the symbol is dl y glycinate the structure will be c h2 n h h c single bond o minus double bond o right donor atoms are nitrogen here and oxygen third one fourth one carbonate co32 minus so the structure will be c double bond o single bond o minus o minus donor atoms are these oxyces ethyl glyoxine dimethyl glyoxine short the symbol is dmg dimethyl glyoxine the symbol is dmg and the structure is h3 c c double c double bond n single bond o minus and here we have c c h3 double bond n o h here donor atom is these two nitrogen dmg is this next one is di pyridyl dy y ri dyl di pyridyl in short we write it as di py di pyridyl the structure is this two pyridyl we have to attach together this is one this is another donor atoms are nitrogen di pyridyl is this all these are bidentically gank two donor atoms we have copied on the structure we will go to the next page mass where is mass then where is mass oh you change the name aditya next one these three structures are important one more thing i'll just forgot to tell you here you see um when the donor atoms are same right the ligands are said to be symmetrical ligand okay when the donor atoms are same okay okay when donor atoms are same the ligands are said to be symmetrical ligand okay so ethylene diamine oxalate glycinate is unsymmetrical nitrogen and oxygen but all these are symmetrical ligands that also you keep in mind donor atoms are same symmetrical ligand okay next when you see the third one we have third type which is tridentate ligand tridentate ligand means the ligand whose density is three three density so we'll have three donor atoms here correct so first example here you see for tridentate ligand the first example we have is di ethylene triamine first example and in short we write as di en di ethylene triamine okay the structure you can understand very easily di ethylene group we have right so we'll write down two ethylene group which is nothing but this ch2 ch2 and here we have one more ch2 ch2 two ethylene group and with this ethylene group three amine group are attached so n h2 this side we have n h2 and here also we have n edge present place okay so donor atoms in this one is n one two three three donor atoms we have correct so di ethylene triamine is this another example we have one more in this that is terpyridine terpyridine in short we write it as terpy terpyridine the structure of terpyridine you see three three pyridine we have here was this one this is three pyridine okay and all the nitrogen atoms are the donor atoms this also donate to the metal this also donate and this also donate okay terpyridine structure is this we can say the donor atoms are same symmetrical consider it would be symmetrically even if it is prided see it's symmetry symmetry in this coordination compound we define the symmetry of ligand as per the donor atom so if donor atoms are same the ligand are said to be symmetrical ligand okay structure we are not considering here got it lick it understood lick it understood no family function where is the next family function lick it prided next one tridented is this so the next example the next type we have tetradentate okay tetradentate ligand tetradentate ligand first example here density is four density is four and the first example here is nitriloacetate nitriloacetate nitriloacetate the structure is this n with this n there are three acetate group attached acetate group is c s 2 c o o minus one is this another one is again c s 2 c o o minus and one more we have c h 2 c o o minus okay donor atom if you see the donor atom here is donor atom here is this oxygen is one this oxygen is two this oxygen is three and the fourth one is this nitrogen all these are four donor atoms correct nitriloacetate b triethylene triethylene tetra amine triethylene three ethylene group will have in this and four amine tetra amine the symbol is tr i e n there is no symbol for this one nitriloacetate this one is not important okay the structure you see triethylene so one ethylene group is this c h 2 whole twice this is one ethylene group and with this two nitrogen attached of amine group n n this structure is not that tough you can understand it easily so one hydrogen will have like this and with this hydro nitrogen we have the other two ethylene group attached c h 2 c h 2 here also whole twice and with this carbon there is n h 2 group attached right so hydrogen uh n h 2 all right like this and with this carbon there is another n h 2 like this so triethylene tetra amine right donor atoms are what donor atoms are all the nitrogen see one is this another one is this next is this and next is this four donor atoms we have hence the density is four okay next one you see two more we have in this two more fourth fifth one is pentadentate ligand pentadentate ligand density is fine okay one example only we have here and the example is example is ethylene diamine triacetate ion ethylene diamine triacetate ion in short we write it as edta 3 minus triacetate ion edta 3 minus the structure is ethylene diamine we have so ethylene is this c h 2 whole twice ethylene diamine diamine means nitrogen attached with it nitrogen nitrogen and with this nitrogen we have three acetate ion attached okay three acetate ion attached so one is this one is this c h 2 c double bond o o minus one acetate ion is this another one is c h 2 c uh double bond o i'll write down this side double bond o o minus here we have one hydrogen because we have triacetate 2 we have this side so one we must have this side which is c h 2 c double bond o o minus okay and in all these you see what are the donor atoms we have five donor atoms because density is five one is this another one is this two three four and fifth one is this oxygen we have five donor atoms in this ethylene diamine triacetate ion and one the last one for this we have the last one here which is uh hexa dendrit ligand hexa dendrit ligand denticity is six example is the same name we have here ethylene diamine ethylene diamine tetra acetate ion tetra acetate ion the symbol is edta tetra acetate we have so four minus edta four minus the only difference in this case is what you can rewrite down the structure of this one see triacetate is this if you replace this hydrogen by another acetate ion the donor atom will be this oxygen the next one so six will be the denticity did you understand the structure here you see the structure of this c h 2 whole twice nitrogen nitrogen c h 2 c double bond o o minus c h 2 c o minus double bond o here we have c h 2 c o minus double bond o and this the last hydrogen is also replaced by acetate ion which is c h 2 c single bond o minus double bond o donor atoms are what donor atoms are one two three four five six donor atoms we have here so these are the classification of ligands based on the charge and denticity okay symbol is important charge on the ligand is important because when we find out the oxidation state we need charge of ligand over there okay can we move on next did you copy this okay there are some different you know the name of the ligands we have according to their nature and properties three four different types of ligands we have that we'll see the first type you write down here next the types of ligand is flexi-dented ligand flexi-dented ligand as the name suggests its denticity is what denticity is flexible okay flexible denticity we have we missed the point simple if i tell you here if one ligand has denticity four correct it does not mean that when this ligand forms the complex okay its denticity will be four always structures of the ligands are not important why structure I have given you because you should know which one is symmetrical which one is not symmetrical correct so symmetry information you must have structure is not required but if you look at the structure the structure is not also difficult you could try to understand okay flexi-dented ligand like I said its denticity is flexible what I was discussing suppose one ligand has denticity four and whenever this ligand forms a complex it is not necessary that the denticity that the denticity of the ligand in the complex will be four it cannot be more than four in any case it can be three it can be two it can be one it can be four also right all poly dented ligands poly dented ligands means what when the ligand denticity is more than one if it is two or more than two right it means what if the ligand is poly dented then it may behave as flexi-dented ligand also depending upon the complex again I am telling you what for a given denti denticity of ligand it is not necessary that all donor atoms of one ligand donate electrons to the metal okay if the denticity is five there are possibility that out of five donor atoms in the ligand only three are donating electron only four are donating electron so if three atoms are donating electron then the denticity of the ligand is three in that particular compound but it is capable of donating five electron pairs maximum denticity is five but depending upon the molecule its denticity can be four can be three can be two understood my point is it clear or not flexi-dented ligands you see the name also suggests that its denticity is flexible depending upon the molecules am I clear tell me lick it below lick it below okay so now write down the definition into this a poly dented ligand I'll write down here also a poly dented ligand is found to have is found to have different denticity different denticity in different compounds in different compounds and they are known as they known as flexi-dented ligand flexi-dented ligands for example you see if I am writing down this ligand e dta e dta four minus what is the name of this ligand what is the name of this ligand it is it is in diamine tetra acetate ion because the charge is four minus the last two ligand you see if the charge is three minus it is tri acetate if the charge is four minus this tetra acetate ion right and what is the denticity of this ligand can you tell me the denticity denticity of this ligand is what how it is for lick its uncle how it is for samyukta ardra aditya how it is for this now I have done it let's go through it once e dta four minus what is the denticity of this ligand if I wrote if I write e dta four minus it is ethylene diamine tetra acetate ion and its denticity will be six not four why did you say four because there are four negative charge is it tell me aditya samyukta four minus charge we have because of four negative oxygen ion but apart from four oxygen ion we have two nitrogen also the donor atom correct so denticity of this is six correct denticity is six but what I said for poly dented ligand poly dented ligand means what we are considering all those ligands whose denticity is two or greater than two okay no issue lick it so denticity is six but the point is this this ligand whose denticity is six it may behave as pentadentated ligand or tetradentated ligand or tight tight dented ligand depending upon the structure of or sorry the structure of the complex basically the denticity is six but it may behave as it is possible that it may behave as it may behave as tetra pentadentated etc tetra tetradentated ligand that is possible and this kind of ligands we call it as we call it as polydentated ligand one example I will give you here to make you understand what it means and how it happens suppose I am writing down this complex you see this CO NH3 CO NH3 4 then we have CO3 close bracket BR this is the molecule we have okay what is this CO what is this CO cobalt CMA right the CO is the central metal atom right this is this is CMA central metal atom what is this NH3 what is NH3 see the central metal atom will always be the transition element the cobalt is the transition element correct what is NH3 NH3 is the ligand right ligand what is CO3 CO3 is the carbonate and it is also a ligand so within the complex we can have more than one ligand also present one more than one different types of ligand also present correct it is not like always we have similar kind of ligand present in the complex we can have two three different different kinds of ligand possible correct these two are ligand this ionization is here that will be counter ion okay now one information I am giving you here and that will discuss later also like few minutes later that this cobalt what is the you know what is the atomic number of cobalt atomic number of cobalt is 27 correct right and next noble gas configuration if you see which is krypton and krypton the atomic number is 36 okay now you now you listen to me very carefully here cobalt has 27 electrons correct and it is accepting electron from the ligands so it has tendency to gain this noble gas configuration and that is why it is accepting electrons from the cobalt right so when it accepts electron from the various ligands that the logic behind this is what if this cobalt has 36 electron in the bonding state it will be stable noble gas configuration and hence it is accepting electrons correct the point is it has tendency to gain this 36 electron but now here this cobalt does not have 27 electrons and to understand how many electron this cobalt has in this structure we need to find out the oxidation state of this cobalt can you tell me the oxidation state of cobalt in this molecule oxidation state of cobalt tell me guys what is the oxidation state of cobalt how do we do this you see dr minus we have correct dr minus so on on whole this complex we'll have plus one charge right plus one charge and you see this ns3 like i told you you should know the charge on the ligand ns3 is neutral so we'll have zero charge on this correct co3 is the carbonate iron right so it has minus two charge on it c double bond o single bond o minus o minus yeah i think three is right so minus two charge on this co carbonate iron zero on this ns3 minus two will go this side plus three plus three is the oxidation state of cobalt understood where is hamsini hamsini just wrote her name in the beginning and then i don't know where she is and then she left i guess hamsini is not there yes means what hamsini left that that's what you mean or this is plus three okay she is studying bio paras is assuming something okay fine fine hamsini is there okay okay yeah yeah i understood hamsini i am sorry i am sorry and paras you should apologize to hamsini okay paras apologize no ah that's better okay now you see what i was trying to explain here the oxidation state is plus three correct so you see the cobalt initially has 27 electron when you write down co plus three it means this cobalt has 24 electron present in this ion correct 24 electron presence and to gain this 36 electron or inert gas configuration it requires 12 more electron is it right okay 12 more electron it requires so from where did but from where this 12 electron this cobalt iron gains this 12 electron it gains from the ligand with which it is attached because we know the ligands are electron pair donor so how many electrons or how many you know donor atoms we require so that we'll get 12 total electron to this cobalt you understood my question cobalt co three plus requires 12 electron to gain this configuration right so we must have six ligands if it is monodentate or in other way we can say we must have two sorry we must have six donor atoms which is getting bonded with this cobalt iron correct to get 12 total electrons cobalt must attached with six donor atoms of the ligand is it clear now you see first of all here this NH3 NH3 is the monodentate ligand or bidented ligand tell me NH3 is monodentate or bidented NH3 monodentate or bidented yeah it's monodentate ligand okay so first of all what we should know it is monodentate ligand correct and this one is carbonate iron it is bidented ligand yes or no bidented ligand correct so far what we have discussed this co3 plus requires 12 electron 12 electron right now you see four monodentate ligand we have written inside this square bracket it means this nitrogen and this cobalt are attached correct this four monodentate ligand donates eight pair of electron sorry total eight electron four pair of electrons and this bidentate which has two oxygen atom as a donor atom so here the both oxygen atom donates electron pair to this cobalt and hence the cobalt will have this 12 electron and hence the bonding completes did you understand this did you understand this see ns3 is monodentated so how many electrons this ns3 donates one ns3 can donate one pair four ns3 we have the total eight electrons it donates and from where the other four electrons this co3 plus get the other four electrons it get from this ligand which has two donor atoms so if I say that both of this oxygen atom is donating electron to this cobalt is it right is it right if I say both oxygen atom of carbonate iron donating electron to cobalt to form the stable complex tell me is it right correct the point is two donor atoms two oxygen are donating electron right that's why this is bidentated here since two oxygen atom is donating electron that's why it is bidentated okay four nitrogen which is monodentated and if it is written inside the square bracket it means it is attached with this metal right so we have to consider all four nitrogen atom here correct now this you understood similarly if I write down one more molecule here you see this one just one change will do in this compare this one co ns3 five instead of four I'll write down five here co3 close bracket okay this is again carbonate and we are this side everything is same even the oxidation state is also same here that is plus three means for this molecule also this cobalt requires 12 electron to get inert gas configuration but again this ns3 is monodentated monodentated and this has capacity to donate two pair of electron because it is bidentated again the maximum capacity is what the maximum density is two for this carbonate ion but how many electrons this ns3 is donating to this cobalt can you tell me how many electrons this ns3 is donating to the cobalt ion 10 is it clear all of you 10 ns3 will have five ns3 molecule so this will donate 10 electrons now next thing how many electrons this co3 plus further requires to get inert gas configuration 10 it 10 electrons it gains from ns3 then how many electrons it requires more two more electron it requires yes understood all of you two more electrons it requires correct so two more electrons this co3 plus requires and from where this two electron this co3 plus gets it gets from the other ligand which is co3 but co3 has capability of donating four electron pairs in total if you see because density is two right so out of the two oxygen atom here only one oxygen atom donates electron pair to this cobalt so in this molecule this co3 ligand is also a monodentated ligand it has capability to donate two pair but this co3 plus requires only two electron only one pair of electron that is why only one oxygen atom donates its electron to this metal and hence it is behaving here as monodentated ligand not bidentated ligand however it has maximum capacity to donate two pair of electron since it is donating only one pair hence it is monodentated in this how many of you understood this clr yes according to the requirement so one thing again i'll tell you here you must be thinking that why not this four ns3 molecule donates eight electron and why not this two oxygen donates one one electron pair to this this four ns3 like we are doing here and two from this two oxygen atom this is what the doubt you have the other oxygen share it will be there as it is it won't take part in bonding with the metal right the other oxygen atom will be there but it won't donate electron to the metal it will be there in the complex but won't take part in bonding with the metal correct so if you have doubt here that why not four ns3 and two oxygen atom of co3 involves that you can that cannot possible here that is not possible here because when any monodentated ligand is written inside the complex okay it means it is bonded with it otherwise there is no point writing down there five ns3 molecule did you understand my point we cannot take here four out of five ns3 we cannot assume four out of five ns3 here because it is written inside the uh square bracket if it is written it is it is attached so we have to consider all monodentated ligand attached with this cobar further this co3 required this co requires only one pair which comes from this co3 molecule this co3 also attached with this cobar but with only one oxygen not with the both oxygen is it clear all of you understood like right clr if you understood all of you correct the point is this is the one example of flexi dented ligand like this only any poly dented ligand poly dented ligand means what its density must be two or more than two any poly dented ligand may behave as you know flexi dented ligand depending upon the structure or the molecular formula of the complex that is this is what flexi dented ligand we have correct next one you write down another type of ligand is chelating ligand right down next type c h e c h e l a t i n g chelating ligand reference you write down all poly dented ligands all poly dented ligands are chelating ligands chelating ligands if on coordination if on coordination it results it results in the formation of in the formation of a closed formation of a closed or or cyclic ring closed or cyclic ring closed structure we get okay next line you write down in this the complexes forms in this way the complexes forms in this way in this way are called are called chelates are called chelates these chelates are comparatively are comparatively more stable more stable than than the ordinary complex ordinary complex okay one thing is what when the donation of electron pair takes place there are tendency to form a cyclic ring for example suppose if I have this suppose we have carbonate ion carbonate ion is this when both carbonate ion when both oxygen atom here takes part in bonding right metal we have here when this oxygen donates electron to the metal so you see we are getting a cyclic ring four member cyclic ring compound so this cyclic ring we call it as chelates okay and because of its cyclic structure only it is normally more stable than than the ordinary complex ordinary complex means what when we have when we have simple compound there is no cyclic ring we get over there in that case it is more stable normally right chelates are more stable than ordinary complex but we have one exception in this exception is what when we get three member ring exception write down write down in case of three member ring three member ring the chelates are less stable right three member ring are generally less stable because of large angular strain and that's why chelates are also less less stable for example you see hydrogen n h2 when n h2 n h2 behaves as a ligand it donates electron pair to the metal and forms a three member ring hence this one is less stable than the ordinary chelates is it clear is it clear tell me what what why does happen tell me what happened three member ring less stable because of angular strain any three member ring is less stable than four member five member like that okay angular strain is more over there no the bond angle is 120 but the hydration of carbon atom over there is sp3 it should be 109 degrees so the angular strain is what angular strain is 109 minus 20 sorry 60 is the bond angle over there so any smaller member ring is less stable than the larger member thing fourth man four member ring is more stable than third five member ring is more stable than four like that as one man so the next one you see ambidently again next page we'll take a break after this ambidently again comes in you want break lick it always wants pizza okay lick it pizza milega dukkini one okay ambidently and write down these ligands these are the ligands which has these are the ligands which has which has more than one which has more than one donor atom which has more than one donor atom available which has more than one donor atom available but in forming complex but in forming complex only one donor atom only one donor atom is attached is attached to the metal ion to the metal ion with example you will understand you see this example suppose I write down cn minus okay c triple bond n minus and carbon has one lone pair if you see this carbon has lone pair so it can donate carbon is a donor atom at the same time nitrogen also has tendency to donate electron because it also has one lone pair on it so this also may donate so carbon nitrogen two donor atoms we have over here so that's why we call it as ambidently again the name of this when carbon donates electron we call it as sino and this one is iso sino okay similarly another example you see n o2 minus n2 minus the structure is this n double bond o single bond o minus nitrogen has lone pair can donate electron and oxygen at the same time also has tendency to donate electron negative charge has tendency to donate electron oxygen so again you see two donor atoms we have here this is also ambidently again which is n o2 minus this is nothing but n o2 minus this is cn minus when nitrogen donates electron we write it as nitrito n when oxygen donates electron it is nitrito oh if in the complex all ambidently again are monodentated okay ambidented no you see this one yeah in the complex it will be monodentated in the complex only one atom donates electron so while forming complex it behaves as monodentated ligand only but the ligand has more than one donor atom available in its um in its formula monofamilar ion whatever it is because it is behaving as monodentated ligand okay when night when in the in the question when n o2 is written it means nitrogen is a donor atom but if it is written like this o n o it means oxygen is a donor atom understood this is it clear another example you see one more example if you have this one o c triple pond n negative charge when oxygen is donating electron we call it as cyanato o nato cyanato nato it is cyanato o when oxygen is donating electron but when nitrogen is donating electron like this o c triple bond n lone pair on this nitrogen donating electron negative charge this we call it as cyanato nato cyanato n this is what the ambidently again we have okay more than one donor atoms present but while forming the complex only one atom attached with the metal hence all embedded ligand behaves as monodentated ligand okay so we'll take a break here and after that we'll see one more terms and then few questions we'll discuss over this okay so take a break now it's 6 23 6 25 so we'll start the class at what time tell me 6 45 pm will resume 7 15 you can come aditya take a 6 45 okay guys can we start okay next time you write down is coordination number coordination number write down it is the number of atoms of ligand it is the number of atoms of ligands that are directly attached directly attached to to the central metal atom or ion by coordinate bond which batch which class you are in okay i'll do that by the way which which class you are in utkars okay class 10th you are already taking class in a centum right utkars do you have contact for contact of tusar sir or like tusar sir contact you have i did not get any messages you have my number i did not get any message from your side i say you do one thing i'm taking class right now just drop your number here i'll just do that i did not get your messages you drop your number here i'll do that okay i'm taking class right now or you can text me on this text me on this okay so the coordination number is the number of atoms of ligands that are directly attached to the central metal atom or ion by coordinate bond okay for example you see if i write down this molecule this complex which is uh cu n h 3 cu n h 3 4 and we have two plus charge over here what is the coordination number for this molecule and then cu n h 3 i'm sorry the another molecule is this cu en whole thrice and then three plus three plus we need to find out the coordination number coordination number of metal will find out on this okay coordination number of metal so first of all you see this means what if you see if you try to you know understand the structure of cu n h 3 whole uh four we have copper we have copper present at the center and the four n h 3 molecule surrounds the copper like this and all these nitrogen atom donates a pair of electron to this copper forms a coordinate bond is this right the number of atom which is attached to the number of atoms of ligands attached directly to the copper or the metal is four hence the coordination number is what coordination number is four for this molecule okay understood this if you understood tell me correct now what is the coordination number of this the second one for the second one the coordination number is what second one tell me the answer is it three six density is two yeah you see this en is ethylene diamine okay if you look at the structure of this complex it will be i forgot to write the charge on this which is two plus the structure of this copper will be here in the center and uh ethylene diamine is nothing but this n h 2 this is one ethylene diamine and like this we have two more right so if you see the number of atom which attached with this metal this is one two three four five and six this is that structure we have ethylene diamine the density is two that's why two atom is donating electron here and we have to count all these atoms so coordination number is six in this one so basically with these two examples if you try to write down the formula of coordination number it is the number of ligands number of ligands present into the density of ligand number of ligand into the density of ligand in the molecule right density of ligand in the molecule right but you have to be a bit careful over here because when you look at this example that we did here for this uh flexi dented ligand this one you see if for this if you find out the coordination number it will be four plus two six correct but here it will be five plus one because here it is more dented ligand right so if you calculate according to the density five into one plus two into one if you see you're getting seven over here which is not possible more than six coordination number you won't get okay more than six coordination number you won't get coordination number six is the most important compound we have for this chapter right so here you must take care of however the density of CO3 is two but in this complex it is more dented ligand so we count one for this by dented ligand we'll count two for this you take care of this thing okay is it clear so we use this formula coordination number into into density density of what density of ligand in the complex okay that is the exact formula we have okay next thing we have to discuss here is the bonding of this coordination compound okay and for that the one first theory which you know the first theory given for this bonding of coordination compound we call it as sigivik ean rule an rule this ean stands for effective atomic number ean stands for effective atomic number okay right down here this is this stands for effective atomic number right down right on to this according to this rule given by sigivik it is the name of the scientist okay utkhar it is 12th class going on no it is not possible that's yeah even coordination number seven or it's not it is not in our syllabus maximum you'll get till coordination number six utkhar this is not for you this is not 10th grade it is 12th grade effective but right down according to the metal sorry according to this rule according to this rule the metal or metal ion metal or metal ion in a complex in a complex tends to acquire tends to acquire acquire noble gas configuration tends to acquire noble gas configuration by gaining electron by gaining electron from ligands okay the basic point is what metals and metal ions tends to acquire noble gas conflict that we discussed in flexi tented ligand okay the same thing we have here tends to acquire noble gas configuration by gaining electrons from ligands one thing here it is what this rule fails in many cases this rule fails in many cases many cases and works and works best for and works best for the metals low oxidation state low oxidation state this was the first attempt to explain the bonding in coordination complex however like we already did in chemical bonding there are many different theories glues dot structure we have we have vbt valence bond theory we have mot molecular orbital theory similarly here also there are many different different theories for coordination complex bonding in coordination complex this was the first theory and what it says that metal ions has tendency to gain the next higher noble gas configuration by gaining electrons from the ligands however this is not true for different different gases different different complexes correct so for example you see if you have to find out the effective atomic number effective atomic number is what see effective atomic number EAN is actually is actually the total number of electrons or the net number of electrons number of electrons of the metal or metal ion of the metal in complex the complex in which the metal is present what is the total number of electron we have that we will see I will discuss that just give me two minutes okay see effective atomic number first of all you see this you will understand effective atomic number the formula I am giving you here it is equals to the atomic number atomic number minus minus number of electron number of electrons loses in the formation of in the formation of of ions and number of electrons will write with sine here so basically it is oxidation state with sine I will just you know in the simple language if I write here this is the oxidation state with sine you'll write down here or instead of this you can write down oxidation state with sine means if it is plus 3 write down plus 3 minus 3 write down minus 3 this or this plus the number of electrons electrons accepted except from ligand it's very simple and state formula it is you see effective atomic number means what net number of electron total number of electron the metal has in bonding state okay so first of all atomic number minus oxidation state oxidation state if it is positive it means it loses electron so atomic number minus the number of electron loses plus the number of electron gains so it is actually the formula of total number of electron did you understand this in a bonding state did you understand this in the bonding this formula did you understand atomic number minus the number of electron lost in forming oxidation state that is plus if it is there plus the number of electrons gains clear? Tell me guys, did you understand this? Yeah, this is the formula we have. Now you see how do we find out the effective atomic number of various molecules? Here you will understand how it was, you know, discussed in case of accident-debted ligand. Okay? First, first example you see, we have K4, FeCN6. We need to find out the effective atomic number for this complex, EAN. Okay? So first of all tell me what is the oxidation state of ion here? What is the oxidation state of this ion? K4, K plus, so it is minus 4, minus 1 on this cyanide group, so minus 6 this side, so it is plus 2. Is it clear? Plus 2 oxidation state. Correct? Now effective atomic number we have to find out, we will use the formula. First of all we will write down the atomic number that is 26 minus oxidation state with cyan, that is plus 2, plus the number of electron except from the ligand. Ligand has 6 more rented, so 6 into 2. What is this value? 6 into 2, 12, plus 26, 38, 38 minus 2, 36. You see this 36 is the atomic number of Kripton and it means what? In this state it gains noble gas configuration, hence it is stable. This is the effective atomic number. Understood this? Understood this guys? Effective atomic number is 36 and that is why it is stable. That's what the Sejvik EAN rule we have. The metal ions has tendency to gain the next higher noble gas configuration by gaining electron from the gas, that's what it means. Now you see another example here, FeCO5, tell me the effective atomic number EAN for this, FeCO5. Third one, CRCO6, effective atomic number. What is the value you are getting? MNCO5. Here what is the number you are getting? Effective atomic number? See, CO carbonyl group is neutral ligand, 0. So oxidation state of ion is also 0. So this will be 26 minus 0 plus 5 into 2, 36. Here also it is 0. So effective atomic number is what? Chromium is 24 minus 0 plus 2 into 6, 36. Again it is stable. What is for this MNCO5 you are getting? For MNCO5 if you calculate effective atomic number EAN, this is again 0. So it is 25 plus 0 minus sorry minus 0 plus 2 into 5 is equals to 10, which is nothing but 35. You are getting 35 here. Are you getting 35? So what happens in this? Since it is not gaining the inert gas configuration. So this molecule dimerizes, right? MNCO4 actually dimerizes and it exists in this form, MN2CO10. This dimerizes and it exists in this form. Now in this form if I try to find out the effective atomic number you see what happens here. Bonding here you see MN and MN are attached with each other and with this there are 5 ligands attached with each MN manganese atom here. 5 here, 1, 2, 3, 4 and 5, correct? So in this one you see what happens. All these 5 ligands COCOCOCOCO. Each of these ligands donates 2 electrons, correct? So 5 into 2, 10 electrons we have here. This is 1 electron for this manganese and this is another electron for this manganese. So if you calculate the effective atomic number for 1 manganese here that will be what? 25 is the atomic number of this manganese plus I am not using that formula. It is different, okay? That formula I am not using. I am just trying to calculate in this bonding state which is a dimer form of this MNCO5. What is the total number of electron this manganese has? Each of these manganese has. So 25 is the atomic number of this. 10 electron donated from each of these ligand plus you see when I say 25 I am counting this electron of this manganese, correct? But this electron I am not counting which is of this manganese atom, right? So for this electron we have to add 1 over here and that's why this becomes 36. Same will be for this manganese and hence the effective atomic number for MN2CO10 is 36 which is the inert gas configuration. That is why MNCO5 dimerize and it exists in this form not in this form. Did you understand this? Is it clear? Any doubt? Let me know guys. All of you understood quickly. Tell me fast. Correct. So this actually this effective atomic number of Siegwick rule is valid only for a few kinds of metal. Metal which has carbonyl group as the ligand mainly for those compounds only it is valid. In general, right? There is no rule for this. But in general the metal which contains carbonyl group as the ligand for those where it is 10. 10 electron because we have 5 ligands. So 1, 2, 3, 4, 5. Each ligands donates how many? 2. So 5 into 2, 10. Yes. Shreya tell me. Correct. Now you see the last part for today we will discuss is the application of EAN rule. Just two, three examples we will see application. See there are two applications for this. One we can find out coordination number to find out coordination number and second one we can also have the idea of reducing an oxidizing behavior. Reducing or oxidizing behavior. Right? Like I said this rule is valid mainly for the metal low oxidation state or with carbonyl ligands. So this one you see if you have this molecule and if I ask you what is the value of X in this? Find the value of X second one. In this also find the value of X. X is nothing but the coordination number we will have here. Third one MnCO6 MnCO6 effective atomic number for this and the last one for today is VCO6 effective atomic number for last two. You see FeCO6 according to EAN rule what we know that the effective atomic number is equals to 36 the next higher configuration. Correct? Now for this it is 0, here also it is 0, here also it is 0, here also it is 0 the oxidation state because this is neutral ligand CO. Okay? So IN has 26 atomic number minus 0 there is no oxidation state plus one of this ligands gives two electrons X gives two X. X value if you find out that will be equals to 5 here. So coordination number is 5 in this. Did you understand this one tell me? So in my book what is the coordination number of second one? X value is what? X value can you tell me? I will write down the answer here tell me the answer 4. Yes X value is 4 coordination number is 4 all of you got this X value 4 any doubt let me know are you getting 4 all of you? MnCO6 what is the effective atomic number for this tell me MnCO6 and VCO6 what is the effective atomic number? EAN for this will be and EAN for this will be what is the effective atomic number here? 37 all of you are getting 37? Okay effective atomic number is 37. So since it has one more electron than the inert gas configuration this molecule has tendency to lose one electron MnCO6 with one positive charge plus one electron and in this state the effective atomic number if you calculate obviously one electron it has loses it has lost so it is 36 right. So you see this is nothing but the oxidizing nature of this this is getting oxidized right losing one electron and hence it is behaving as what? This molecule has tendency to lose one electron to gain inert gas configuration so this molecule is behaving as reducing agent is it clear this molecule has 37 electrons so it has tendency to lose one electron to gain 36 inert gas configuration it means it is behaving as a reducing agent fine what is the effective atomic number here you will get here 35 yes or no 35 means to gain 36 electron it has tendency to accept one electron and forms VCO6 one negative charge on this means it is getting reduced it means this molecule is behaving as what? oxidizing agent any doubt understood all of you? So this is the two application of EAS rule we have that is to find out our coordination number and reducing oxidizing behavior okay however this rule is valid only for few molecules generally the complexes complexes which has CO as the ligand mainly for those only it is valid MnCO5 may behave as oxidizing agent fine but it is not stable in that form because of 35 electrons when you take MnCA5 and if you have if you want to understand whether it is behaving as reducing and oxidizing agent obviously it is an oxidizing agent correct but since 35 is not a stable configuration and that is why it get dimerized and forms stable configuration MnCO5 magnies has very odd structures okay that kind of dimerization is very less tendency will have in this vanadium carbonyl compound that you have okay so even that's the thing so you will you won't get any a different question to this they only ask you to find out like this X or oxidizing and reducing behavior fine so we'll wind up the class here next class we'll start with nomenclature in coordination compound and then you'll see the other bonding theory okay any doubt and why should I mean okay any doubt guys so see you in the next class bye thank you all the best for your exam tomorrow