Arrange the Nitrogens in histidine in increasing order of their basic strength.
@seshu_ram @pratyaksh_tyagi @Supreeta_Sen @Azimuddin_Sheikh
Please send the picture of the concerned nitrogen atoms... like mark them 1 2 3 and then we can arrange.
Most basic nitrogen in this considering we are taking nitrogen counting from left to right will be 2>3>1
I’m just taking a shot in the dark not sure if it’s right.
My reason is that in 1 there is no resonance or any other effect, thus no electron displacement.
For 2 it can resonate the most.
And 3 comes in the middle.
but bro cant N_1's lone pair be in resonance with the oxygen's double bond
How bro? There are 2 bonds between them.
my bad.. sorry yeah
then the reason for 1>3>2 would be... sp_2 nitrogen is less basic than sp_3 nitrogen
Yes bro and resonance too. LP of 2 can go both sides but not of 3.
Zwitter ion can be formed, right?
Yes, that's what I think.
Then the basic strength is compromised for N1
How then will we decide the order?
Also, is the nitrogen marked 3 has its lone pair delocalised?
Bro, 3's lone pair can resonate only one side, but the other one could get delocalised either way. Also sp3 N is more basic as @Vikrant_Reddy mentioned.
Idk what if there’s H bonding?
Why complicating bro?
NH2 upon formation of zwitter ion should lose all its capacity to donate electron.
Then how can we say that sp3 character will help in anyway?
@Chirag_Hegde can you confirm?
@Yash2 u made a point... but doesn't zwitter ion form only at pI .. when the basic strength a compound is asked.. shouldn't we be considering a general state...
Yaa I agree with @Vikrant_Reddy
Yeah that makes sense.
Guess I am thinking too much
lol yeah.. try not to complicate things