作者:Frank G. Riddell、Eric S. Turner
DOI:10.1016/0040-4020(79)80059-9
日期:1979.1
Conformational equilibria and nitrogen inversion barriers in some tetrahydro-1,2,5-oxadiazines have been investigated by 1H NMR spectroscopy and by chemical equilibration. The conformational free energy differences obtained are: 4-methyl, 1.2±0.2; 6-p-nitrophenyl, 1.4±0.2kcal mole−1. Barriers to inversion of the N atom at position 2 are in the region 14.1–15.6 kcal mole−1. The conformational behaviour
通过1 H NMR光谱和化学平衡研究了某些四氢-1,2,5-恶二嗪中的构象平衡和氮转化障碍。所获得的构象自由能差为:4-甲基,1.2±0.2;6-对硝基苯基,1.4±0.2kcal摩尔-1。在位置2处N原子反转的障碍在14.1–15.6 kcal摩尔-1范围内。四氢-1,2,5-恶二嗪环的构象行为表明是由四氢-1,2和1,3-恶嗪环的行为方面组成的。