 Friends, next in this session we are going to discuss the effect of hyper conjugation on bond order or bond length. So, we will write down here effect of hyper conjugation on bond order or bond length. So, friends we already know that this bond order is inversely proportional to bond length. Bond order is inversely proportional to bond length. So, any one of these comparison if you get you can write down the other one also. For example, you see with one example I will try to explain this. Suppose we have to compare the bond order of carbon carbon double bond in this with the carbon carbon double bond in this. So, if it is alpha and beta. So, we have to compare the bond order of alpha and beta. And if you get this you can get bond length also. So, to understand this comparison what we will do we will try to draw the hyper conjugative structure of this. If I write this molecule like this. So, the hyper conjugative structure will be what this sigma comes over here and pi comes over here. So, the hyper conjugative structure here it will be C H 2 double bond C H single bond C H 2 negative H plus here. So, we have to compare this bond right this bond we have to compare. So, pi is converting into sigma right pi is converting into sigma. So, what happens here we can have three hyper conjugating structure where we have the sigma bond present ok. And one structure has double bond here, but here in this no hyper conjugation no hyper conjugation present here. So, for this molecule the bond order will be 2 right, but for this molecule the bond order will be somewhere between 1 and 2 right. I think it will if you see since the mode the hyper conjugating structure that we are getting here in all those hyper conjugating structure we have carbon carbon single bond present here right. So, we can say the bond order of this carbon carbon double bond here it is close to 1 right it will be somewhere between 1 to 1.5, but we are not again going to calculate the exact value, but we can definitely say that bond order with value will be between 1 and 2. So, if you compare the bond order here. So, bond order of alpha is greater than bond order of beta and we can also say if you have the bond order. So, bond length of alpha is less than bond length of beta. So, bond order comparison if you have accordingly you can write down the comparison of bond length ok. So, one thing we can conclude here that if more number of hyper conjugating structure in which the double bond is converting into single bond then its hyper then its bond order will be less. Suppose one example if I in this molecule there is no there is only one double there is no hyper conjugation here here we have hyper conjugation right. So, in this it is very clear since there is no hyper conjugation bond order is 2 and here it will be between 1 and 2, but what happens if 2 molecule will show hyper conjugation. For example, if I take this 2 molecule C H 3 C H 2 C H double bond C H 2 this molecule you have to compare the bond order of this right. And another molecule is this I will write down here C H 3 C H double bond C H 2 this one beta right. So, these 2 bond order you have to calculate. Now you see if here we have number of alpha hydrogen is what 2 number of alpha hydrogen here it is 3 and if you draw the hyper conjugative structure of this. So, that will be C H 2 double bond C H single bond C H 2 negative charge H plus we have here. And here it will be C H 3 C H H plus double bond C H single bond C H 2 negative charge. But this kind of how many this kind of a structure possible here and how many this kind of a structure possible here. Here we have only 2 structure possible like this where we have carbon carbon single bond because we have 2 alpha hydrogen, but here there are 3 similar structure possible where the carbon carbon has single bond. So, if you compare since more number of hyper conjugating structure we have here in which we have carbon carbon single bond present. So, if you compare the bond order of alpha and beta. So, bond order of alpha is more than the bond order of beta why because in beta we have more number of hyper conjugative structure where carbon carbon single bond is present. Here we have carbon carbon single bond, but here the number of a structure with such bond is lesser in comparison. That is why the bond order of this is more than this and bond length will be reverse the order of this. I hope you understood this concept that I have discussed here. If you do not have hyper conjugation fine, but if you have hyper conjugation then you have to check that whether the bond whether the you know how many hyper conjugative structure we have in which carbon carbon single bond or double bond is present. According to that you can easily decide. Suppose if you comparing the bond order of this, this one and this one here right. Suppose we are comparing the bond order of I will write down this star mark, this star mark and this tick mark these two carbon bond length if you are comparing. So, due to hyper conjugation what happens here you see this sigma bond is converting into pi single bond is converting into double bond. So, bond order is increasing here also the single bond is converting into double bond. Bond order is increasing, but the number of hyper conjugative structure we have in which we have this kind of bond is more over here right in comparison to this. Here we have two such structures, but here we have three structures possible. Hence we can say the bond order of this bond is more than to that of this. So, bond order comparison it always depends on what carbon carbon bond you are looking at. That is why I have mentioned alpha beta and alpha beta here according to that. So, you cannot actually say that because of hyper conjugation the bond order is decreasing right. We cannot say this it depends what carbon carbon bond we are considering. So, I hope you understand this will write down I will write down few examples here we will compare the bond order then. So, all these molecule we are comparing the bond order you can pause the video and solve it I am discussing it now. So, here you see here we do not have hyper conjugation right. So, alpha hydrogen is 0 here no hyper conjugation here alpha hydrogen is 2 plus 2 4 right. So, we have hyper conjugation because of that this double bond has tendency to convert into what single bond right and hence the bond order of we have to compare the bond order right. So, I will write down the heading bond order and bond length will be reverse of this the order of bond length will be reverse. So, because of hyper conjugation this double bond convert into single bond order of first will be more than together of second number of alpha hydrogen here 2 number of alpha hydrogen here 2 plus 3 5. So, more hyper conjugation here we have where this double bond will convert into single bond. So, bond order of first is more than to that of second here you see this bond order correct this one and this one here what we have resonance possible. Here we have hyper conjugation and here we have no effect right. So, because of resonance what happens this pi will convert this bond comes over here right. So, we have conjugation like this right. So, this single bond has tendency to convert into double bond. This single bond has tendency to convert into double bond here we have hyper conjugation double bond has tendency to convert into single bond right and here we have single bond. So, if you see the bond order of alpha is maximum then we have beta and then we have gamma. In beta the bond order will be any value between 1 and 2 right it is near to 1 in this it is exactly 1 right it is slightly more than 1 and it is it is what close to 2 order will be this ok. Here again we have resonance this pi will convert into sigma and here we have hyper conjugation resonance is always dominating right resonance is always dominating this has more tendency to convert into sigma bond order of beta is more than to that of alpha ok. Now, in this last question you see this is alkene right. So, bond order is 2 beta will have maximum here here we have resonance right. So, this bond order will be minimum and gamma will be in between. So, because of resonance if double bond is converting into single bond the bond order is lesser than the hyper conjugation in which the double bond is converting into single bond. So, 2 things you have to keep in mind here the effect which is taking place whether it is resonance hyper conjugation and because of that effect whether the double bond is converting into sigma into single bond or the single bond is converting into double bond. Like here you see in this example the single bond is converting into double bond because of resonance that is why the you know the bond order of alpha is maximum here, but here you see because of resonance the double bond is converting into single bond right that is why it is you know it is a bond order is minimum over here alpha ok. So, you do not have to generalize this thing that because of hyper conjugation or resonance bond order increases or decreases right it depends on what kind of a structure we have and what bond we are considering right what bond you are looking at to calculate the bond order right. So, all these are the discussion of bond order ok. One more example I will show you here ok this molecule you see here you see we have hyper conjugation possible and here we have resonance right. So, because of resonance what happens here the sigma bond is converting into single bond is converting into double right this if you draw the you know resonating a structure of this one you will get this structure we have a free radical here double bond. So, single bond is converting into double bond here what happens the hyper conjugative is structure of here it is and we have h plus here right. So, again you see the sigma bond is converting into double bond single bond is converting into double bond ok. So, both kind of things are there right, but since the resonance is more dominating effect. So, this molecule has more tendency to convert into double bond right and that is why the stability of this or the bond order of this is more than to that of the first one ok. This is how we discuss bond order and bond length will be what exactly the reverse of disorder if you have to calculate the bond length. The next thing we are discussing here is bread's rule right what it says it says sp2 hybridized carbon head position highly unstable unstable not possible sp2 hybridized carbon at bridge head position is highly unstable and not possible what is bridge head position you see if I draw this a structure right. So, if you have carbocation present over here on this carbon right. So, you see this carbon or this carbon that you have here it is what it is now sp2 hybridized. If it is sp2 hybridized then it should be trigonal planet and to maintain this trigonal planet structure this bond should come to this side because trigonal planet is nothing, but this structure ok this one right. So, this bond has tendency to come over this side right, but which is not possible here because this is connected with this carbon this carbon and this here right this is a bi-cycloding bi-cyclocompound ok. So, because of this what happens this positive charge here what happens we have maximum angle strain here right and because of that angle strain this molecule is not stable high angle strain. So, that is what the bread's rule is this position is the bridge head position is the bridge head position and at bridge head position sp2 hybridized carbon is highly unstable ok. One more example if I show you this one this is also unstable and not possible bridge head position not possible what about this one this is possible this is stable this is not the bridge head position you see this is structure we have here right. So, this is possible this molecule is also possible here also it is a stable here it is not stable the positive charge here it is not stable ok. Even if I consider an alkene also like this if the positive charge is not there suppose I will give double bond here this alkene is also not stable because again it is sp2 hybridized. So, this kind of a structure only it is not possible ok this kind of a structure is possible this double bond it is possible ok. So, sometimes they will give you this question and they will ask you which of these you know structure or carbocation does not exist or highly unstable. So, what we have to keep in mind at bridge head position sp2 hybridized carbon should not be there sp2 you must remember do not remember this carbocation because here you see it is not a carbocation, but it is sp2 hybridized ok. So, sp2 hybridized carbon is not possible at bridge head position.