3-acidbasepkatable.pdf
DESCRIPTION
Acid Base pKa Table chemistryTRANSCRIPT
pKas: Table of Data Group Acid Dissociation Reaction pKa
protonated nitro group
protonated nitrile
(nitrilium)
protonated ketone
protonated thiol
(sulfonium)
NO
OH N
O
O
H +
H +C N HCH3 C NCH3
H +CH3
CCH3
OH
CH3C
CH3
O
CH3 SH
HH + CH3 S
H
–11.3
–10.1
–7.2
–6.8
Strongest Acid Weakest Base
sp N+
sp2 O+
sp3 S+
Group Acid Dissociation Reaction pKa
protonated phenol
(oxonium)
protonated ester
protonated carboxylic
acid
protonated sulfide
(sulfonium)
H +CH3
COCH2CH3
OH
CH3C
OCH2CH3
O
CH3 SCH3
HH + CH3 S
CH3
OH
H
H +O
H
H +CH3
COH
OH
CH3C
OH
O
–6.7
–6.5
–6.1
–5.4
Why is carbonyl oxygen more basic? –6.2 (HCl) =
Group Acid Dissociation Reaction pKa
protonated ether
protonated amide
(amidinium)
carboxylic acid
(e– deficient)
phosphoric acid
H +CH3
CNH2
OH
CH3C
NH2
O
CH3CH2 OCH2CH3
HH +
H +CF3
CO
O
CF3C
O
O
CH3CH2 OCH2CH3
CH3CH2 OH
HH + CH3CH2 O
H
H
H +HO P OO
OH
HHO P O
O
OH
–3.6
–2.4
0.2
2.1
protonated alcohol
0
Group Acid Dissociation Reaction pKa
anilinium
pyridinium
iminium
imidazolium
H +CH3
CCH3
NH
H +CH3
CO
O
CH3C
O
OH
NH
HH
H + NH
H
H +NH
N
CH3
CH3C
CH3
NCH3
N
N
H
H
H +
N
NH
4.6
4.7
5.5
7.0
carboxylic acid
5.3
Group Acid Dissociation Reaction pKa
phosphoric acid
(monobasic)
1,3-diketone
ammonium
phenol O
H H + O
H +HO P OO
OH
HO P OO
O
H +
CCC
CH3
O
S
OCH3CH2
H HC
CCCH3
O
S
OCH3CH2
H
H +C
CCCH3
O
CH3
O
H HC
CCCH3
O
CH3
O
H
CH3 N HCH3
CH3
H + CH3 NCH3
CH3
7.2
8.5
9.8
10.0
β-keto thioester
9.0
Group Acid Dissociation Reaction pKa
thiol
iminium (C-H acid)
phosphate (dibasic)
guanidinium
H +O P OO
O
H +
CCC
CH3
O
O
OCH3CH2
H HC
CCCH3
O
O
OCH3CH2
H
H +
CH3CH2S
H H + CH3CH2S
CH3C
C
NCH3 CH3
H
HH
H +CH3
CC
NCH3 CH3
H
H
HO P O
O
O
NC
N
NH H
H
HH
CH3 NC
N
NH
H
HH
CH3
10.5
11.0
12.4
13.2
β-keto-ester
11.0
Group Acid Dissociation Reaction pKa
imidazole
alcohol
ketone
ester
CH3CH2O
H H + CH3CH2O
CH3C
N
OH
H
H +
H +N
NH
N
N
CH3C
N
O
H
CH3C
C
OH
H
H +CH3
CC
O
HH
H
OCH2CH3C
C
OH
H
H +OCH2CH3
CC
O
HH
H
14.4
15.0
20
24.5
amide
15.9
Group Acid Dissociation Reaction pKa
terminal alkyne
amine
benzylic C-H
H +
H +
H +
H +
C C HH C CH
C NCH
HH
C NCH
H
CH3 NH
HCH3 N
H
CH
HH C
H
H
25
25
41
nitrile (α C-H)
35