Focal point analysis of the reaction barriers (in kcal mol−1) for the pericyclic reactions of Scheme 1a.
| Basis set | ΔEe(HF) | +δ[MP2] | +δ[CCSD] | +δ[CCSD(T)] | +δ[CCSDT(Q)] | NET |
|---|---|---|---|---|---|---|
| Diels-Alder reaction | ||||||
| cc-pVDZ (134) | 43.61 | −31.21 | 13.60 | −4.85 | 0.46–0.53 | 21.07 |
| aug′-cc-pVDZ (188) | 43.41 | −34.54 | 14.40 | −5.35 | [−0.07] | [17.86] |
| aug′-cc-pVTZ (416) | 45.10 | −35.88 | 15.13 | −5.78 | [−0.07] | [18.50] |
| aug′-cc-pVQZ (780) | 45.39 | −35.68 | 15.32 | −5.90 | [−0.07] | [19.06] |
| aug′-cc-pV5Z (1312) | 45.45 | −35.59 | [15.39] | [−5.94] | [−0.07] | [19.24] |
| CBS LIMIT | [45.47] | [−35.49] | [15.47] | [−5.99] | [−0.07] | [19.38] |
| ΔEfinal = ΔEe(NET/CBS) + Δ(DBOC) + Δ(rel) + Δ(core) = 19.38 + 0.04 + 0.03 + 0.11 = 19.56 kcal mol−1 | ||||||
| ΔE0 = ΔEfinal + Δ(ZPVE) = 19.56 + 2.38 = 21.94 kcal mol−1 | ||||||
| 1,3-Dipolar cycloaddition | ||||||
| cc-pVDZ (119) | 39.31 | −27.73 | 10.95 | −4.64 | 0.70–0.82 | 17.77 |
| aug′-cc-pVDZ (173) | 40.60 | −32.84 | 12.31 | −5.49 | [−0.12] | [14.47] |
| aug′-cc-pVTZ (374) | 43.22 | −33.33 | 13.12 | −5.78 | [−0.12] | [17.11] |
| aug′-cc-pVQZ (690) | 43.49 | −33.10 | 13.34 | −5.89 | [−0.12] | [17.73] |
| aug′-cc-pV5Z (1147) | 43.60 | −33.06 | [13.42] | [−5.93] | [−0.12] | [17.91] |
| CBS LIMIT | [43.65] | [−33.03] | [13.50] | [−5.98] | [−0.12] | [18.03] |
| ΔEfinal = ΔEe(NET/CBS) + Δ(DBOC) + Δ(rel) + Δ(core) = 18.03 + 0.02 + 0.01 + 0.23 = 18.29 kcal mol−1 | ||||||
| ΔE0 = ΔEfinal + Δ(ZPVE) = 18.29 + 1.71 = 20.00 kcal mol−1 | ||||||
| Electrocyclic rearrangement | ||||||
| cc-pVDZ (86) | 56.42 | −15.23 | 4.93 | −2.64 | 0.16–0.29 | 43.35 |
| aug′-cc-pVDZ (122) | 55.85 | −15.60 | 5.19 | −2.75 | [−0.13] | [42.56] |
| aug′-cc-pVTZ (268) | 56.55 | −16.34 | 5.79 | −3.01 | [−0.13] | [42.87] |
| aug′-cc-pVQZ (500) | 56.70 | −16.32 | 5.93 | −3.08 | [−0.13] | [43.10] |
| aug′-cc-pV5Z (838) | 56.72 | −16.32 | [5.99] | [−3.10] | [−0.13] | [43.16] |
| CBS LIMIT | [56.73] | [−16.32] | [6.04] | [−3.13] | [−0.13] | [43.19] |
| ΔEfinal = ΔEe(NET/CBS) + Δ(DBOC) + Δ(rel) + Δ(core) = 43.19 + 0.04 + 0.01 + 0.20 = 43.44 kcal mol−1 | ||||||
| ΔE0 = ΔEfinal + Δ(ZPVE) = 43.44 − 0.78 = 42.66 kcal mol−1 | ||||||
| Sigmatropic rearrangement | ||||||
| cc-pVDZ (110) | 53.88 | −22.92 | 9.46 | −3.57 | 0.27–0.41 | 36.71 |
| aug′-cc-pVDZ (155) | 53.71 | −23.24 | 9.77 | −3.69 | [−0.14] | [36.40] |
| aug′-cc-pVTZ (342) | 54.90 | −24.18 | 10.24 | −4.12 | [−0.14] | [36.71] |
| aug′-cc-pVQZ (640) | 54.98 | −24.32 | 10.34 | −4.21 | [−0.14] | [36.64] |
| aug′-cc-pV5Z (1075) | 55.00 | −24.34 | [10.37] | [−4.25] | [−0.14] | [36.64] |
| CBS LIMIT | [55.01] | [−24.36] | [10.41] | [−4.29] | [−0.14] | [36.63] |
| ΔEfinal = ΔEe(NET/CBS) + Δ(DBOC) + Δ(rel) + Δ(core) = 36.63 + 0.08 + 0.00 + 0.08 = 36.79 kcal mol−1 | ||||||
| ΔE0 = ΔEfinal + Δ(ZPVE) = 36.79 − 4.23 = 32.56 kcal mol−1 | ||||||
| Double group transfer | ||||||
| cc-pVDZ (106) | 80.06 | −36.85 | 12.53 | −4.69 | 0.30–0.56 | 50.79 |
| aug′-cc-pVDZ (142) | 80.08 | −38.54 | 13.03 | −5.09 | [−0.16] | [49.21] |
| aug′-cc-pVTZ (324) | 82.15 | −40.08 | 13.88 | −5.83 | [−0.16] | [49.85] |
| aug′-cc-pVQZ (620) | 82.33 | −40.16 | 14.08 | −6.00 | [−0.16] | [49.99] |
| aug′-cc-pV5Z (1058) | 82.39 | −40.13 | [14.15] | [−6.06] | [−0.16] | [50.03] |
| CBS LIMIT | [82.41] | [−40.11] | [14.22] | [−6.12] | [−0.16] | [50.14] |
| ΔEfinal = ΔEe(NET/CBS) + Δ(DBOC) + Δ(rel) + Δ(core) = 50.14 + 0.07 + 0.02 + 0.00 = 50.23 kcal mol−1 | ||||||
| ΔE0 = ΔEfinal + Δ(ZPVE) = 50.23 − 2.44 = 47.79 kcal mol−1 | ||||||
a
Please see the footnote of Table 1 for notation.