Table 6. Electronic Energies (in kJ/mol, Relative to the trans Compound 2 for cis (1) and trans (2) Minima), Transition States and Associated Intermediates Calculated at Different Levels of Theory.
| (A)
dissociative mechanism |
(B) associative | (C) twist | |||||||
|---|---|---|---|---|---|---|---|---|---|
| method | cis (1) | cis-ts | cis-min | ts | trans-min | trans-ts | trans (2) | tsa | tst |
| B3LYPgasa | 15.28 | 96.03 | 91.29 | 92.12 | 72.85 | 86.6 | 0 | 139.19 | 193 |
| B3LYPsolb | –3.94 | 111.99 | 107.65 | 125.3 | 90.56 | 94.82 | 0 | 140.47 | 189.09 |
| B2GP-PLYPgasc | 27.61 | 118.38 | 109.04 | 112.08 | 87.02 | 105.99 | 0 | 163.68 | 192.58 |
| B2GP-LYPsold | 0.8 | 124.65 | 114.19 | 140.45 | 95.52 | 103.61 | 0 | 158.56 | 199.43 |
| ΔH0 | 16.0 | 138.8e | 0 | 138.8e | 138.8e | ||||
a
B3LYP/6-31G*.
b
PCM-B3LYP/6-311G*//B3LYP/6-31G*.
c
B2GP-PLYP/6-311G*//B3LYP/6-31G*.
d
PCM-B2GP-PLYP/6-311G*//B3LYP/6-31G*.
e
Activation enthalpy is obtained without explicit considerations of a particular transition state.