Pyramidal nitrogen inversion hindered by a strong intramolecular hydrogén bond in 2-diethylaminomethylphenols
作者:G. S. Denisov、V. A. Gindin、N. S. Golubev、A. I. Koltsov、S. N. Smirnov、M. A. And L. Rospenk Koll Sobczyk
DOI:10.1002/mrc.1260311116
日期:1993.11
of the O‐methylated derivative (2) this process is fast (on the NMR time‐scale) down to 150 K. The frequencies and the activation parameters of the nitrogen inversion in (1) were measured by DNMR, which indicated that the inversion requires a preliminary stage of breaking an intramolecular hydrogen bond. The activation enthalpy, δH inv‡ , of the inversion stage was evaluated as 28.5 ± 6.7 kJ mol−1.
在低于 260 K 的 2-二乙基氨基甲基-3,4,6-三氯苯酚 (1) 的 1H NMR 光谱中,发现 CH2 信号的额外分裂,这可以归因于受阻氮反转。在 O-甲基化衍生物 (2) 的分子中,这个过程很快(在 NMR 时间尺度上)低至 150 K。 (1) 中氮转化的频率和活化参数是通过 DNMR 测量的,这表明反转需要破坏分子内氢键的初步阶段。转化阶段的活化焓 δH inv‡ 被评估为 28.5 ± 6.7 kJ mol-1。