????????????????????????? OH- ?????????? Kb ??

1
?????????????? Amines(Basicity of Amines)
????????????????????????? OH- ?????????? Kb
?? ????????????? Amines ?????????? ????????? ???
Amines ???????? pKb ?????????????????? ????
???????????? pKb - log Kb
Kb
??? pKb ??? ammonia ???????????? 4.75
2
????????????????????????? ammonia ??? Amines
???????? ?
pKb
pKb
4.75
2.88
3.34
9.37
3.27
8.75
4.19
Amines ???????? pKb ??????????????????????
3
Aliphatic amine ?????????????? NH3 ??? Aromatic
amine (?? N ???????? benzene)
??? ???????
Aromatic amine
???????????? lone pair e- ??? N-atom ??? Aromatic
amine ?????? delocalized (???????????)
??????benzene????? ??????????? e- ??? N-atom ????
4
????????????????????????? Aliphatic amine
(1oamine)
(2oamine)
(3oamine )
2o amine gt 1o amine
gt 3o amine
????CH3?????????? e- ????? N ??????????? ???????
e- ??????? ????????????????????????
??? 3oamine ?? steric hindered (????????)???
lone pair e- ??? N ????????????????????
5
?????????????????????? ????? N ?? Hybridization
???????
N ??????? sp3 ?????????????? N ??????? sp2
???????????????????? e- ??? p-orbital ??? N-sp2
(s33.3,p 66.6) ?????????? N-sp3 (s25,p75)
?????????????????????????
6
Amide ??????????????? Amine
??????????? e- ??? N ??? Amide ???? ?????????
delocalized (???????????)??? e- ??? N ????? O
???????? resonance effect ????? Amide
??????????????? Amine
resonance effect ??? Amide
7
???????????????????????????? (Substituent effect
on Basic Strenght)
???????????????????????????-NH2
??????????? electron(EWG)????????????
???????? ??????????????????????????? -NH2
??????????? electron(EDG)
8
Nitrogen atom ??????????????????
3
1
LSD
2
2
2
Nicotine
1
1
Xylocain(anesthetic)