The conformational preference of the methyl group of 1-methyl-1-germacyclohexane was studied experimentally in solution (low-temperature 13C NMR) and by quantum chemical calculations (CCSD(T), MP2 and DFT methods). The NMR experiment resulted in an axial/equatorial ratio of 44/56 mol% at 114 K corresponding to an A value (A = G ax − G eq) of 0.06 kcal mol−1. An average value for ΔG e→a # = 5.0 ± 0.1 kcal mol−1 was obtained for the temperature range 106–134 K. The experimental results are very well reproduced by the calculations. CCSD(T)/CBS calculations + thermal corrections resulted in an A value of 0.02 kcal mol−1, whereas a ΔE value of −0.01 kcal mol−1 at 0 K was obtained.
通过溶液实验(低温 13C NMR)和量子化学计算(CCSD(T)、MP2 和 DFT 方法)研究了 1-甲基-1-锗环己烷甲基的构象偏好。核磁共振实验结果表明,在 114 K 时,轴向/赤道比为 44/56 mol% ,对应的 A 值(A = G ax - G eq)为 0.06 kcal mol-1。在 106-134 K 的温度范围内,得到了 ΔG e→a # = 5.0 ± 0.1 kcal mol-1 的平均值。计算结果很好地再现了实验结果。CCSD(T)/CBS 计算 + 热校正得到的 A 值为 0.02 kcal mol-1 ,而在 0 K 时得到的 ΔE 值为 -0.01 kcal mol-1 。