Table 3.

Relative energies for esters as the function of the rotation about the C-O and C-S bonds ^a.

	Gas	Chloroform	Acetonitrile
	ΔEint	ΔEint + ΔG(solv)	ΔEint + ΔG(solv)
O=C-O-C
0	0.0	0.0 + 0.0 = 0.0	0.0 + 0.0 = 0.0
30	2.88	2.91 − 0.04 = 2.87	2.95 − 0.12 = 2.83
60	8.76	8.85 − 0.13 = 8.72	8.96 − 0.35 = 8.61
TS(95.4, 92.2, 90.7)	12.40	12.59 − 0.75 = 11.84	12.80 − 1.29 = 11.51
120	11.15	11.54 − 1.57 = 9.97	11.98 − 2.61 = 9.37
150	7.00	7.96 − 2.48 = 5.48	8.59 − 4.02 = 4.57
180	5.71	6.37 − 2.86 = 3.51	7.09 − 4.59 = 2.50
ΔGth	0.89	1.09	1.10
ΔGth(TS)	0.44	0.48	0.40
O=C-S-C
0	0.0	0.0 + 0.0 = 0.0	0.0 + 0.0 = 0.0
30	2.72	2.76 + 0.02 = 2.78	2.80 − 0.03 = 2.77
60	8.86	8.93 − 0.12 = 8.81	9.00 − 0.32 = 8.68
90	12.16	12.34 − 0.61 = 11.73	12.55 − 1.17 = 11.38
120	10.27	10.60 − 1.10 = 9.50	10.89 − 1.87 = 9.02
150	5.63	6.08 − 1.62 = 4.46	6.57 − 2.72 = 3.85
180	3.35	3.86 − 1.89 = 1.97	4.42 − 3.12 = 1.30
ΔGth	1.18	1.29	1.31
S=C-O-C
0	0.0	0.0 + 0.0 = 0.0	0.0 + 0.0 = 0.0
30	2.83	2.84 + 0.00 = 2.84	2.86 − 0.04 = 2.82
60	8.95	8.98 + 0.00 = 8.98	9.02 − 0.11 = 8.91
90	12.94	13.04 − 0.35 = 12.69	13.17 − 0.72 = 12.45
120	11.61	11.94 − 1.37 = 10.57	12.33 − 2.32 = 10.01
150	7.81	8.44 − 2.64 = 5.80	9.14 − 4.30 = 4.84
180	6.25	7.00 − 3.19 = 3.81	7.83 − 5.13 = 2.70
ΔGth	0.10	0.42	0.51
S=C-S-C
0	0.0	0.0 + 0.0 = 0.0	0.0 + 0.0 = 0.0
30	3.02	3.00 − 0.15 = 2.85	3.03 − 0.28 = 2.75
60	9.96	9.86 + 0.12 = 9.98	9.76 + 0.16 = 9.92
TS(90.6, 89.7, 89.0)	14.30	14.27 + 0.07 = 14.34	14.24 − 0.10 = 14.14
120	11.40	11.52 − 0.93 = 10.59	11.71 − 1.55 = 10.16
150	5.60	6.03 − 1.92 = 4.11	6.62 − 3.20 = 3.42
180	3.10	3.65 − 2.05 = 1.60	4.30 − 3.42 = 0.88
ΔGth	0.16	0.80	1.10
ΔGth(TS)	0.47	0.85	1.16

^a Energies in kcal/mol, torsion angles in deg. Local-energy-minima torsion angles are underscored.