Supplementary Information
The quest for a better system for evaluating pi-electron substituent constant: a comparison of
benzoic, acrylic and tria-, penta-, heptafulvene-based carboxylic acids. A computational study
Wojciech P. Oziminski
National Medicines Institute, 00-725 Warszawa, 30/34 Chełmska Street, Poland
ΔGdis(3-carboxypentafulvene)
350
345
340
335
330
325
320
315
315
320
325
330
335
340
345
350
ΔGdis(4-carboxypentafulvene)
Figure S1. Linear regression of Gibbs free energy of dissociation of 3-carboxypentafulvene
and 4-carboxypentafulvene. Regression equation: y = 1.106 x - 34.982; Correlation
coefficient: R = 0.998
ΔGdis(4-carboxyheptafulvene)
335
330
325
320
315
310
305
305
310
315
320
325
330
335
ΔGdis(5-carboxyheptafulvene)
Figure S2. Linear regression of Gibbs free energy of dissociation of 4-carboxyheptafulvene
and 5-carboxyheptafulvene. Regression equation: y = 0.996 x + 0.9267; Correlation
coefficient: R = 0.999
ΔGdis(3-carboxyheptafulvene)
335
330
325
320
315
310
305
305
310
315
320
325
330
335
ΔGdis(6-carboxyheptafulvene)
Figure S3. Linear regression of Gibbs free energy of dissociation of 3-carboxyheptafulvene
and 6-carboxyheptafulvene. Regression equation: y = 1.244 x - 80.857 ; Correlation
coefficient: R = 0.972
Table S1. Gibbs free energy of dissociation of benzoic acids. Energy in kcal/mol.
substituent
BH2
CHO
CN
COCN
NO2
CF3
Me
Cl
F
OH
OMe
NH2
NMe2
H
ΔGdis(meta-)
327.05
323.06
320.76
318.79
319.69
323.24
331.57
325.62
326.65
329.28
330.51
332.72
333.76
330.96
ΔGdis(para-)
324.74
322.51
319.98
316.34
318.05
322.36
332.40
326.34
327.88
331.96
332.99
335.44
337.04
330.96
Table S2. Gibbs free energy of dissociation of pentafulvene-based carboxylic acids. Energy in
kcal/mol.
substituent
BH2
CHO
CN
COCN
NO2
CF3
Me
Cl
F
OH
OMe
NH2
NMe2
H
ΔGdis(2-)
330.52
326.48
323.51
321.12
321.46
325.59
335.70
329.29
330.17
333.87
336.32
339.63
341.20
334.36
ΔGdis(3-)
325.61
322.94
322.32
316.88
319.46
324.31
334.92
329.36
330.72
334.82
337.69
341.62
343.64
332.27
ΔGdis(4-)
327.08
323.24
323.30
317.92
320.35
324.65
334.22
329.39
330.84
333.17
337.22
340.16
342.61
332.27
Table S3. Gibbs free energy of dissociation of heptafulvene-based carboxylic acids. Energy in
kcal/mol.
substituent
BH2
CHO
CN
COCN
NO2
CF3
Me
Cl
F
OH
OMe
NH2
NMe2
H
ΔGdis(2-)
320.74
317.59
316.53
310.57
313.93
320.00
329.68
323.88
324.90
328.49
328.82
331.14
330.10
327.99
ΔGdis(3-)
319.01
317.28
316.43
309.98
312.22
318.58
329.19
323.96
325.58
330.79
331.08
333.44
331.19
327.36
ΔGdis(4-)
318.34
317.24
316.54
309.61
312.24
318.52
328.53
323.83
325.68
331.04
330.84
331.56
329.22
327.05
ΔGdis(5-)
318.45
317.22
317.10
310.31
312.93
319.03
328.76
324.40
326.05
331.22
331.29
332.28
330.51
327.05
ΔGdis(6-)
321.05
318.11
318.79
315.20
319.00
321.00
328.82
324.02
326.33
332.29
333.01
331.18
330.91
327.36
Table S4. Gibbs free energy of dissociation of acrylic and methacrylic acids. Energy in
kcal/mol.
BH2
CHO
CN
COCN
NO2
CF3
Me
Cl
F
OH
OMe
NH2
NMe2
H
Acrylic acid
324.52
320.65
318.19
310.52
313.61
321.14
336.63
326.79
329.22
335.64
337.11
342.92
343.47
334.25
Methacrylic acid
323.86
321.15
319.47
311.14
315.21
322.62
335.72
326.15
329.71
335.27
336.73
342.45
340.67
334.45
Note: Calculated Gibbs free energy of proton is -0.01001 Hartree