ABSTRACT We investigated the reactivity of some para-substitued Schiff bases by performing quantum chemical calculations using the density functional theory method. First, we employed this method to predict reliable orbital molecular energies. Then, we calculated the quantum chemical parameters: energy gap, chemical hardness and Mullikan electronegativity. Our simulated results prove that the presence of intermolecular hydrogen bond increases the gap in HOPySB4 Schiff base and the electrophilicity index increases with electronegativity effect (ClPySB2). So, we deduce that the reactivity and selectivity are generated by its structure. This study establishes that the fraction of electrons for HOPySB4 is large. We have also evaluated the conformations of these molecules using the molecular dynamics simulation in gas and in solution. We conform that the HOPySB4 reaches its high stable conformation state in the solution environment. We compared theses calculated results and conclude that the HOPySB4 Schiff base is an inhibitor of choice. Molecular simulations give us very good results in the prediction of reactivity and inhibition effect.

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缓蚀效果席夫碱反应性预测的理论研究

摘要我们通过使用密度泛函理论方法进行量子化学计算，研究了一些对位取代的席夫碱的反应性。首先，我们采用这种方法来预测可靠的轨道分子能量。然后，我们计算了量子化学参数：能隙、化学硬度和马利坎电负性。我们的模拟结果证明分子间氢键的存在增加了 HOPySB4 席夫碱的间隙，并且亲电指数随着电负性效应（ClPySB2）而增加。因此，我们推断反应性和选择性是由其结构产生的。这项研究表明 HOPySB4 的电子比例很大。我们还使用气体和溶液中的分子动力学模拟评估了这些分子的构象。我们认为 HOPySB4 在溶液环境中达到其高度稳定的构象状态。我们比较了这些计算结果并得出结论，HOPySB4 Schiff 碱是首选的抑制剂。分子模拟在预测反应性和抑制作用方面给了我们很好的结果。