Question
Sun October 14, 2012 By:
 

what is zwitter ion,diazotisation?

Expert Reply
Mon October 15, 2012
The carboxylic acid group being acidic tends to lose a proton, and the amine group being basic tends to gain a proton.

Amino acids in solution exist as an equilibrium mixture of neutral molecules and dipolar ions called zwitterions:

H2N - R
|
C
|
H
- COOH
neutral molecule
+H3N - R
|
C
|
H
- COO-
zwitterion
Diazotization is a reaction that converts an -NH2 group connected to a phenyl ring to a diazonium salt. Diazotization reactions are extremely useful in organic synthesis. The nitrous acid provides NO+ which replaces a hydrogen on the -NH3+ group to produce -NH2NO+ and water; a second water is eliminated to produce the -N2+ group.
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