Table 5.

Relative energies for ethers 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)
Furan, O-C-O-C
0	1.53	1.38 + 0.72 = 2.10	1.18 + 1.16 = 2.32
45.1	1.43
49.9		1.31 + 0.74 = 2.05
53.9			1.18 + 1.11 = 2.29
90	2.12	2.05 + 0.58 = 2.63	1.97 + 0.79 = 2.76
120	2.41	2.39 + 0.23 = 2.62	2.37 + 0.27 = 2.64
150	1.11	1.11 + 0.05 = 1.16	1.11 + 0.04 = 1.15
180	0.0	0.0 + 0.0 = 0.0	0.0 + 0.0 = 0.0
ΔGth		−1.30	−0.78
Furan, O-C-S-C
0	1.92	1.83 − 0.06 = 1.77	1.70 + 0.10 = 1.80
30	1.14	1.06 +0.03 = 1.03	0.95 + 0.19 = 1.14
69.2	0.0
73.7		0.0 + 0.0 = 0.0
75.9			0.0 + 0.0 = 0.0
90	0.31	0.32 − 0.09 = 0.23	0.33 − 0.15 = 0.18
120	1.35	1.39 − 0.35 = 1.04	1.45 − 0.54 = 0.91
150	1.45	1.49 − 0.60 = 0.89	1.56 − 0.85 = 0.71
180	0.92	0.96 − 0.60 = 0.36	1.01 − 0.80 = 0.21
ΔGth		0.34	0.78
Thiophene, S-C-O-C
0	0.87	0.81 + 0.17 = 0.98	0.70 + 0.36 = 1.06
6.3		0.81 + 0.15 = 0.96
5.1			0.70 + 0.35 = 1.05
30	1.10	1.04 + 0.22 = 1.26	0.94 + 0.40 = 1.34
60	1.58	1.52 + 0.03 = 1.55	1.44 + 0.60 = 2.04
90	1.89	1.86 + 0.05 = 1.91	1.80 + 0.49 = 2.29
120	1.98	1.97 − 0.03 = 1.94	1.95 + 0.29 = 2.24
150	0.90	0.90 − 0.01 = 0.89	0.89 + 0.0 = 0.89
180	0.0	0.0 + 0.0 = 0.0	0.0 + 0.0 = 0.0
ΔGth		−0.16	−0.40
Thiophene, S-C-S-C
0	1.10	1.06 − 0.52 = 0.54	1.01 − 0.55 = 0.46
30	0.78	0.75 − 0.32 = 0.43	0.70 − 0.34 = 0.36
60	0.21	0.19 − 0.10 = 0.09	0.16 − 0.08 = 0.08
82.7	0.0
83.3		0.0 + 0.0 = 0.0
83.8			0.0 + 0.0 = 0.0
120	0.66	0.69 − 0.29 = 0.40	0.72 − 0.42 = 0.30
150	0.99	1.02 − 0.59 = 0.43	1.08 − 0.82 = 0.26
171.9		0.85 − 0.73 = 0.12
172.1			0.88 − 0.97 = -0.09
180	0.81	0.84 − 0.67 = 0.17	0.88 − 0.92 = -0.04
ΔGth		0.52	0.67

^a Energies in kcal/mol, torsion angles in deg. See also the footnotes for Table 3.