amines Flashcards
structure of RNH2
pyramidal
why is angle less trhan 109’5 for amine
due to presence of unshared e-
why is redu with iron scrap with HCL preffered
Fecl2 formed gets hydoolysed to release HCL during rnx and only small amount of HCL si need to initaite rnx
ammonolysis
the process of cleavage of R-X bond by ammonia
why ammonolysis is disadvantageous
due it its production of mixture of 1o,2o,3o and quarternary ammonium salt
1o amine is obtained as amahor produt by taking large excess of ammonia
why cant aryl amine be prepared by GPHTSYS
ARyl halides do not undergo nucleophilic subtiwith anion fromed by phtalimide
decreasing order of BP
1>2>3
what makes maines reactive
- electronegativity btwn N and H
- unshared e- of N
amines behacve as nucleophle du to(2)
lewis base - amine
aliphatic amines are stronger bases
+I effectog alkyl grp
leading to hig e- densityon N atom
opposite of aryl amines- eWg of aryl decrases e- density on N and hence they are less basic thqan AMMONIA
how is amine stabilised by ALKYL GROUP
BY+ I effect it disperses the posittive charge
what all factors influence basisity of amines in AQUEOS STATE
- steric hinderance
- +I inductive efff
- solvation eff
WHY IS pKb value for aniline quite high
-NH2 IS DIRECTLY ATTACHED TO BEN
results in unshaare e- on N to be in conjugation with ben
so it makes e- less avalable for PROTONATION
order of basisity of amines in gaseous state
3>2>1>nh3
order of basisity of
1. ethannamien
2. methananime
in AQUOES state
- 2>3>1> NH3
- 2>1>3> NH3
ERG attache to aniline decreases the basicity
EWGattached to aniline increases the basicity
-OCH3, -CH3
-NO2,-SO3H,-COOH,-X
