邻苯三酚自氧化机理的量子化学研究

Quantum chemical study on sponteneous mechenism of pyrogallol

以WINMOPAC7.21和MOPAC2012中提供的PM6半经验量子化学方法研究了邻苯三酚自氧化机理。PM6半经验量子化学方法首先对邻苯三酚自氧化过程相关的各分子进行构型优化,利用提供的热力学参数计算获得了的热力学参数,包括分子的生成热,分子的熵,从而计算出每步反应的吉布斯自由能的变化值,进行反应自发性评价,揭示自氧化反应发生的可能性。由各相关分子的最高占有轨道,和最低空轨道能量的分析,获得了分子的第一电离势等与电子相关的分子指数,研究了邻苯三酚自氧化过程的机理,为文献推测的机理提供了量子化学的支撑。

The autoxidation mechanism of pyrogallol was studied by PM6 program from WINMOPAC7.21 and MOPAC2012 semi-empirical quantum chemistry methods. The molecular parameters of molecules related to the pyrogallol autoxidation mechanism such as heat of molecule formation, molecular entropy, which were used to calculate reaction heat and Gibbs free energy, and used to evaluate the reaction spontansity. The highest occupied molecular orbital, the lowest unoccupied orbital were also obtained from PM6 semi-empirical quantum chemistry calculations, from which some indixes of molecules related to the electron transfer properties, and also responsible for the autoxidation mechanism of pyrogallol in aqueous solution. The theoretical results were well accord with the experimental results in literature, and offer useful data for the further studies of the compound.