On the basicity of organic bases in different media
Ph3N
(2,6−Cl2−C6H3)3P
2,3,4,5,6−Cl5−Aniline
(2,6−F2−C6H3)2(Ph)P
(C6F5)(Ph)2P
Cl−Phenylfulvene
Thymine
2,3,5,6−Cl4−Aniline
H−Phenylfulvene
(2−F−C6H4)3P
5−Cl−2−NO2−Aniline
Uracil
Me−Phenylfulvene
2−Cl−4−NO2−Aniline
4−Cl−2−NO2−Aniline
BINAPH+
BIPHEPH+
(2−F−C6H4)2(Ph)P
MeO−Phenylfulvene
2−NO2−Aniline
6−NO2−Indazole
5−NO2−Indazole
2,6−Cl2−Aniline
(2,6−F2−C6H3)(Ph)2P
2−NO2−Imidazole
Ph2P−(CH2)2−PPh2−H+
Ph2NH
(2−F−C6H4)(Ph)2P
4−NO2−Aniline
2,5−Cl2−Aniline
4−NO2−Imidazole
4−NO2−N ,N−Dimethylaniline
MePh2N
(1−Napht)3P
2−Cl−Pyridine
Benzotriazole
TMPH+
Ph2P−(CH2)3−PPh2−H+
Quinoxaline
Caffeine
Indazole
Ph3P
2,6−(MeO)2−Pyridine
4−F−3−NO2−Aniline
3−NO2−Aniline
Pyrazine
OEPH+
BINAP
2−Cl−Aniline
1,2,3−triazole
BIPHEP
4−CF3−Aniline
9−O−1,5−(COOMe)2−N ,N'−Ph2−Bispidine
3−NO2−N ,N−Dimethylaniline
Ph2P−(CH2)4−PPh2−H+
2,4−F2−Aniline
4−(4−NO2−C6H4−N=N)−Aniline
TCPPH+
4−CF3−N ,N−Dimethylaniline
Pyrimidine
4−SCN−N ,N−Dimethylaniline
TPPH+
Pyrazole
Quinazoline
Ph2P−(CH2)2−PPh2
4−Br−Aniline
3−Cl−Pyridine
3−Br−N ,N−Dimethylaniline
1−NaphtNH2
Ph2P−(CH2)3−PPh2
2−MeO−Pyridine
MePh2P
TCPP
Pyridazine
(4−MeO−C6H4)3P
4−Br−N ,N−Dimethylaniline
TMP
Ph2P−(CH2)4−PPh2
dma−Phenylfulvene
5−NO2−Benzimidazole
TPP
2−Me−Aniline
Aniline
7,8−Benzoquinoline
N−Me−Aniline
9−Cl−Acridine
3−MeO−N ,N−Dimethylaniline
4−NO−N ,N−Dimethylaniline
2,2'−Biquinoline
N ,N−Dimethylaniline
8−NH2−2−Me−Quinoline
Phthalazine
4−MeO−Aniline
5,6−Benzoquinoline
Quinoline
4−Me−N ,N−Dimethylaniline
Carbendazim
2,2'−Bipyridine
OEP
Thiabendazole
Pyridine
Me2PhP
Acridine
Isoquinoline
4−MeO−N ,N−Dimethylaniline
2−Me−Pyridine
9−O−N ,N'−(CHPh2)2−Bispidine
Benzimidazole
2−NH2−Acridine
Phenanthroline
9−O−1,5−(COOMe)2−N ,N'−Bn2−Bispidine
4−CF3−7−N=P1(Ph)3−Coumarin
N ,N'−Ph2−Bispidine
2,6−Me2−Pyridine
2,6−(NO2)2−C6H3P1(pyrr)3
3−NH2−Pyridine
4−MeO−Pyridine
2,6−Cl2−4−NO2−C6H2P1(pyrr)3
2−NH2−Pyridine
2,6−(NH2)2−Pyridine
4−(4−NO2−C6H4−N=N)−C6H4P1(Ph)3
2,4−(NO2)2−C6H3P1(pyrr)3
2,4,6−Me3−Pyridine
Imidazole
4−CF3−7−N=P1(Ph)2pyrr−Coumarin
2,3−(NH2)2−Pyridine
Me3P
4−(Ph−N=N)−C6H4P1(Ph)3
Me2P−(CH2)2−PMe2
2−NH2−Benzimidazole
4−(4−dma−C6H4−N=N)−C6H4P1(Ph)3
4−(4−NO2−C6H4−N=N)−C6H4P1(Ph)2pyrr
2−NH2−1−Me−Benzimidazole
3−NH2−Acridine
2−NO2−4−CF3−C6H3P1(pyrr)3
4−CF3−7−N=P1(pyrr)2Ph−Coumarin
4−(Ph−N=N)−C6H4P1(Ph)2pyrr
BnNH2
9−O−N ,N'−Bn2−Bispidine
2−NO2−5−Cl−C6H3P1(pyrr)3
4−(4−dma−C6H4−N=N)−C6H4P1(Ph)2pyrr
N ,N'−Me2−Piperazine
9−O−1,5−Me2−N ,N'−Bn2−Bispidine
4−(Ph−N=N)−C6H4P1(dma)2Ph
4−NH2−Pyridine
2−NO2−4−Cl−C6H3P1(pyrr)3
4−(4−NO2−C6H4−N=N)−C6H4P1(pyrr)2Ph
N ,N'−(CHPh2)2−Bispidine
4−dma−Pyridine
N−Me−Piperazine
N−Me−Piperidine
Me2BuN
Pr3N
Me2EtN
4−pyrr−Pyridine
9−NH2−Acridine
Cyclohexylamine
4−(Ph−N=N)−C6H4P1(pyrr)2Ph
PrNH2
4−NO2−C6H4P1(pyrr)3
2,5−Cl2−C6H3P1(pyrr)3
[H][Ph]Triazine
2,6−Cl2−C6H3P1(pyrr)3
4−CF3−7−N=P1(pyrr)3−Coumarin
ProtonSp−dma
N ,N−Me2−Cyclohexylamine
Me2N−(CH2)2−NMe2
Piperazine
i−Pr2NH
Et3N
N−Me−Cyclohexylamine
MePrNH
Me2NH
4−(4−dma−C6H4−N=N)−C6H4P1(pyrr)2Ph
2−Cl−C6H4P1(dma)3
Homopiperazine
[Me][Ph]Triazine
Me2N−(CH2)3−NMe2
Piperidine
4−(4−NO2−C6H4−N=N)−C6H4P1(pyrr)3
Quino[7,8−h ]quinoline
Pyrrolidine
Me2N−(CH2)3−NH2
1−(o−Tolyl)biguanide
NH2−(CH2)3−NH2
Me2N−(CH2)4−NMe2
MeNH−(CH2)3−NMe2
MeNH−(CH2)3−NH2
Me2N−(CH2)2CHMe−NMe2
2−Cl−C6H4P1(pyrr)3
4−CF3−C6H4P1(pyrr)3
4−(Ph−N=N)−C6H4P1(pyrr)3
MeHN−(CH2)3−NHMe
1−NaphtP1(pyrr)3
PhTMG
4−(4−dma−C6H4−N=N)−C6H4P1(pyrr)3
PhP1(dma)2Me
4−Br−C6H4P1(pyrr)3
PhP1(dma)3
N ,N'−(CHMePh)2−Bispidine
N ,N'−Bn2−Bispidine
Bispidine
(−)−Sparteine
PhP1(pyrr)3
N ,N'−Me2−Bispidine
[Me][i−Pr]Triazine
4−MeO−C6H4P1(pyrr)3
[4−MeO−C6H4][i−Pr]IYA
TMG
4−dma−C6H4P1(pyrr)3
2−{hpp}C5H4N
2−Cl−C6H4P2(dma)5
DBU
[H][i−Pr]IYA
4−NO2−C6H4−CH=P(dma)3
PhP1(dma)2tmg
[OMe][OMe]Guanidine
[OMe][H]Guanidine
[H][OMe]Guanidine
[H][H]Guanidine
ProtonSp−tmg
4−CF3−C6H4P2(pyrr)5
Me2−IP
2−Cl−C6H4P2(pyrr)5
MTBD
4−NO2−C6H4−CH=P(pyrr)3
IP
2,6−{hpp}2C5H3N
[dma][H]Guanidine
HP1(dma)3
TBD
[CH2−t−Bu][i−Pr]IYA
4−Br−C6H4P2(pyrr)5
PhP2(dma)5
[H][dma]Guanidine
[(CH2)3OMe][(CH2)3OMe]TMAIMG
t−BuP1(pip)3
t−BuP1(dma)3
HP1(pyrr)3
[i−Pr][i−Pr]TMAIMG
[dma][dma]Guanidine
[Me][i−Pr]IYA
[ch][ch]TMAIMG
t−BuP1(TACD)
MeP1(dma)3
[Et][(CH2)3dma]TMAIMG
PhP2(pyrr)5
[(CH2)3dma][(CH2)3dma]TMAIMG
[i−Pr][i−Pr]IYA
4−MeO−C6H4P2(pyrr)5
t−BuP1(pyrr)3
EtP1(pyrr)3
H2C{hpp}2
PhP1(tmg)2dma
4−CF3−C6H4P3(dma)7
2,5−Cl2−C6H3P3(pyrr)6NEt2
HP1(pyrr−2−CH2−N−pyrr)3
[CMe2−t−Bu][i−Pr]IYA
[t−Bu][CH2−t−Bu]IYA
ProtonSp−N=P(dma)3
[CMe2CH2−t−Bu][i−Pr]IYA
2−Cl−C6H4P3(dma)6NEt2
[t−Bu][i−Pr]IYA
ProtonSp−N=P(i−Pr)3
ProtonSp−N=P(Me)3
4−CF3−C6H4P3(pyrr)7
ProtonSp−N=P(cp)3
4−NO2−C6H4−CH=P(tmp)3
ProtonSp−N=P(n−Bu)3
2−Cl−C6H4P3(pyrr)6NEt2
Ph−CH=P(dma)3
PhP1(tmg)3
PhP3(dma)7
4−MeO−C6H4P3(dma)7
ProtonSp−N=P(pyrr)3
Ph−CH=P(pyrr)3
PhP3(pyrr)7
t−BuP2(dma)5
Ph−CH=P(−NMe−CH2−CH2−)3N
Compound
0.03
1.120.78
0.48
0.610.51
0.98
0.150.08
0.70
0.10
1.28
0.66
0.32
0.14
1.22
1.05
0.50
0.81
0.08
0.64
0.610.17
0.64
0.60
0.69
1.21
0.550.25
0.95
1.03
1.04
1.70
0.81
1.050.61
0.25
1.56
0.28
1.111.23
1.77
0.63
1.20
0.03
0.63
1.09
0.100.35 0.42
0.440.05
0.50
1.59
0.46
0.58 0.77
1.89
1.44
1.26
0.68
0.01
0.60
1.691.69
0.04
0.08
1.07
0.21
0.25
0.70
1.20
0.08
0.98
0.47
1.17
0.401.14
1.60
0.210.09 0.30
0.37
0.65
1.33
0.27
0.10
0.74
0.44
0.45
0.51
0.22
0.75
0.73
0.52
0.06
0.900.98
1.60
1.05
0.630.65
0.180.18
0.590.61
0.77
0.56
0.41
0.25
1.07
0.49
0.04
0.310.28
1.01
0.770.65
0.88
1.10
0.43
0.570.37
0.95
0.56
0.850.48
0.19 0.370.40
0.13
0.03
0.38
0.33
0.14
0.12
1.77
0.73
0.99
0.85
0.20
0.17
0.35
0.25
0.44
0.17
0.44
0.20
0.05
0.01
0.05
1.43
0.04
0.86
0.86
0.23
0.67
0.85
0.240.27
0.24
1.28
0.25
−0.01
1.040.91
0.68
0.11
0.25
0.22
1.110.97
1.66
0.50
0.560.45
1.31
1.010.86
0.30
0.570.39
0.97
0.27
0.240.28
0.611.05
1.210.68
1.72
0.11
0.80
1.09
0.89
0.38
1.35
0.19
1.01
1.61
0.13
0.930.86
1.360.86
0.55
1.60
0.84 2.10
1.49
0.34
0.61
0.09
1.57
0.34
0.45
2.22
0.77
0.740.72
0.41
0.11
0.080.06
0.67
0.62
2.10
0.810.80
2.20
0.59
1.100.99
1.01
0.59
0.46
0.09
0.91
0.59
0.06
0.02
0.43
0.25
0.17
0.59
0.78
0.65
0.93
1.02
0.19
0.27
1.01
0.77
0.85
1.31
1.96
1.29
0.940.93
0.84
0.98
1.13
0.36
0.01 0.22
0.34
0.35
0.05
0.34
0.17
0.52
0.45
0.38
1.02
0.95
0.55
0.790.79
0.15
1.72
0.89
0.680.36
0.71
0.560.69
1.02
1.58
0.59
0.21
0.04
1.16
0.591.00
0.85
1.07
0.38
0.06
0.28
0.200.14
0.41
0.43
0.16
0.24
0.30
0.11
1.57
0.37
0.74
0.88
1.18
0.830.75
0.15
0.420.35
0.14
0.17
0.16
0.11
0.070.07
1.40
0.05
0.37
0.58
0.77
0.57 0.31
0.31
1.20
0.44
0.25
0.68
1.180.48
0.36
1.301.16
0.06
1.14
0.260.25
0.14
0.96
0.33
0.24
0.47
0.19
0.78
0.36
0.670.63
0.64
1.031.40
0.910.58
0.60
1.52
1.13
0.14
0.80
0.100.01
0.02
0.94
0.88
0.13
1.40
1.55
2.540.42
0.21
0.23
0.69
0.44
0.07
1.10
0.45
0.05
0.52
0.00
0.75
0.65
0.17
0.49
0.90
0.24
0.46
0.40
0.42
1.07
1.07
1.10
0.83
1.08
1.13
0.36
0.13
0.55
0.90
0.47
0.28
0.41
0.57
0.69
1.030.66
0.25
0.68
0.440.45
0.120.07
0.79
1.28
0.59
0.74
0.22
0.74
0.49
0.24
1.37
1.90
1.06
0.59
0.72
1.11
0.71
0.48 0.35
0.36
1.52
0.30
0.04
0.88
1.95
0.28
0.160.28
0.69
0.35 0.29
0.53
1.16
0.13
0.94
0.27
0.670.24
0.15
0.260.19
1.92
0.18
0.14
0.49
0.36
1.01
0.70
0.19
1.52
0.48
1.10
0.23
0.66
1.511.40
1.42
0.42
0.43
0.06
1.40
0.60
0.520.43
0.96
1.38
0.77
0.06
0.18
0.59
0.31
0.74
2.29
1.50
2.10
1.83
1.05
1.70
1.23
0.46
1.93
0.430.18
0.12
0.99
0.10
0.350.45
0.460.56
1.381.20
1.12
0.240.12
0.39
0.41
0.68
0.31
1.000.19
0.54
0.96
0.850.65
0.45
0.60
0.25
0.77
0.58
0.74
0.45
0.400.34
0.23
0.04
0.29
0.04
0.68
0.21
0.59
0.80
1.04
0.76
0.10
0.34
0.57
0.85
0.67 1.08
0.19
0.62
0.15
0.47
1.04
0.23
0.08
0.07
0.90
0.40
0.77
0.40
0.83
0.06
1.50
0.03
0.23
0.21
0.34
1.15
0.09
1.04
1.24
0.72
1.240.17
1.16
0.09
0.011.12
0.28
0.440.46
0.88
0.99
0.560.31
0.250.08
0.040.51
0.16
0.62
0.08
0.97
0.45
1.16
0.50
0.94
1.50
0.59
0.60
0.110.04
1.43
0.48
0.19
0.04
0.26
0.05
0.19
0.52
0.36
1.67
0.45
0.26
0.73
0.76
0.51
0.64
0.62
0.35
0.83
1.15
0.54
0.60
0.320.00
0.54
1.21
0.87
1.40
0.63
0.22
2.20
0.53
0.67
0.45
0.79
1.32
0.21
0.270.59
0.67
1.84
1.00
1.10
1.55
0.25
0.56
0.85
0.15
0.50
0.10
0.40
0.26
0.300.19
0.18
0.25
0.39
0.53
0.25
0.95
1.60
0.90
1.54
1.48
1.70
0.64
0.33
0.87
0.77
0.39
0.25
0.40
0.27
0.44
1.60
0.98
0.48
0.82
0.19
0.90
0.09
0.17
0.83
0.15
1.28
1.70
2.32
2.50
2.54
2.56
2.68
2.72
2.90
3.01
3.18
3.36
3.50
3.65
3.68
3.8
4.0
4.56
4.56
4.80
4.87
4.91
5.07
5.17
5.55
5.8
5.98
6.11
6.22
6.23
6.34
6.46
6.52
6.55
6.79
6.89
7.0
7.4
7.40
7.51
7.61
7.62
7.65
7.68
7.68
7.74
7.8
7.79
7.86
8.0
7.99
8.03
8.14
8.26
8.3
8.39
8.50
8.5
8.60
8.72
8.78
9.0
9.1
9.20
9.38
9.44
9.56
9.64
9.78
9.84
9.94
9.97
10.01
10.06
10.06
10.13
10.16
10.23
10.30
10.41
10.48
10.49
10.64
10.85
10.97
11.07
11.22
11.27
11.28
11.47
11.56
11.56
11.87
11.96
11.97
12.24
12.25
12.27
12.38
12.41
12.53
12.64
12.66
12.68
12.72
13.28
13.51
13.54
13.67
13.69
13.84
13.92
14.00
14.16
14.17
14.21
14.24
14.45
14.50
14.78
14.90
14.91
15.00
15.07
15.24
15.26
15.48
15.58
15.6
16.10
16.18
16.22
16.32
16.40
16.54
16.86
16.86
16.92
16.94
17.28
17.34
17.38
17.49
17.51
17.63
17.70
17.74
17.79
17.96
18.06
18.24
18.25
18.26
18.33
18.35
18.36
18.36
18.39
18.44
18.50
18.50
18.52
18.56
18.58
18.63
18.67
18.69
18.69
18.82
18.83
18.91
18.93
19.03
19.04
19.10
19.11
19.17
19.28
19.35
19.51
19.60
19.62
19.63
19.72
19.76
19.96
20.07
20.10
20.15
20.19
20.25
20.27
20.45
20.61
20.85
20.88
21.06
21.20
21.26
21.28
21.39
21.56
21.67
22.32
22.73
23.02
23.11
23.24
23.35
23.86
24.2
24.23
24.31
24.44
24.53
24.67
24.73
24.79
24.82
24.90
24.92
25.27
25.30
25.40
25.47
25.49
25.52
25.7
25.83
25.85
26.02
26.25
26.30
26.44
26.63
26.66
26.70
26.98
27.01
27.11
27.15
27.2
27.25
27.38
27.52
27.54
27.56
27.66
27.98
28.23
28.42
28.88
28.98
29.06
29.08
29.15
29.31
29.47
29.89
29.89
29.95
30.14
30.20
30.32
30.32
30.46
30.55
30.68
31.05
31.17
31.24
31.34
31.44
31.95
32.06
32.42
32.74
33.09
33.14
pKaH Directly measured ∆pK aH
Compound family:Phosphorylides
Phosphazenes
1,8−Naphtyl−Proton Sponges
Amidines
Aliphatic amines
Heterocycles
Porphyrines
Aromatic amines
Phosphanes
Phenylfulvenes
dma pyrr pip cp ch
tmg bn 1-Napht tmp
Ph-CH=P(-NMe-CH2-CH2-)3N
ProtonSp-R
XP1(R)3 XP2(R)5 XP3(R)7 XP3(R)6NEt2
t-BuP1(TACD) HP1(pyrr-2-CH2-N-pyrr)3 4-CF3-7-N=P1(R)3-Coumarin3
TBD MTBD DBU
[R1][R2]Guanidine TMG PhTMG
[R1][R2]TMAIMG [R1][R2]Triazine 1-(o-Tolyl)biguanide
[R1][R2]IYA IP Me2-IP
H2C{hpp}2 2,6-{hpp}2C5H3N 2-{hpp}C5H4N
Pyrrolidine Piperidine
Bispidine (-)-Sparteine
Piperazine Homopiperazine
9
1 5
1
2
3
45
6
7
8
6
7
8
5
91
4 10
2
3
4
7
5
61
2
3
4
7
5
61
3
2
1
2
34
5
4
5
6
3
2
1
Benzotriazole
2,2´-Bipyridine Phenanthroline
Isoquinoline
2,2´-Biquinoline
Quinoline
5,6-Benzoquinoline7,8-Benzoquinoline
Pyridazine
Pyrazole
Acridine
Pyrimidine
Pyrazine
Indazole
CaffeineUracil
Benzimidazole
Pyridine
Quinoxaline
Phthalazine 1,2,3-Triazole
Quino[7,8-h]quinoline
Imidazole
Carbendazim
Thymine
Thiabendazole
Quinazoline
OEP TPP
TMP TCPP
BIPHEP BINAP
Ph2 Ph2
Ph2Ph2
X-Phenylfulvene
* Protonation site
*