Table 7. Energies and Gibbs Free Energies (in Italics) of the Dimerization Reactions with Different Substituents at the ωB97X-D/6-311G** Levela.
| substituents (R) | 2R | 8R | 12R | 21R |
|---|---|---|---|---|
| tBu | –44.6/–25.1 | –53.6/–35.1 | –43.0/–22.7 | –63.5/–42.7 |
| TMS | –45.9/–32.4 | –58.4/–36.2 | –47.0/–24.2 | –60.0/–39.7 |
| TTMS | –29.7/–20.6 | –49.2/–14.2 | –43.6/–6.6 | –20.5/11.4 |
| DMP | –49.4/–32.4 | –62.0/–35.8 | –45.2/–21.2 | –48.2/–21.8 |
| DTBP | –25.5/–9.7 | –29.7/–1.0 | 10.5 [9.0]/35.7 | 8.0 [9.0]/37.5 |
| BTMSP | –39.3/–19.7 | –28.4/–13.2 | 0.8 [−3.3]/29.4 | 1.6 [0.7]/31.2 |
a
tBu: tert-butyl; TMS: trimethylsilyl; TTMS = tris(trimethylsilyl)silyl; DMP = 2,6-dimethyl-phenyl; DTBP = 2,6-di-tert-butylphenyl; BTMSP = 2,6-bis(trimethylsilyl)-phenyl, LNO-CCSD(T)/CBS dimerization energies in brackets.