Glyoxal can be important in atmospheric chemistry in terms of its ability to convert to secondary organic aerosols. In this study, the glyoxal-breaking reaction by two atmospheric active radicals, NO2 and NH2, has been investigated at the B3LYP and M06-2X levels in connection with 6-311++G(d,p) basis set. The formation of the most stable adducts from glyoxal with NO2/NH2 radical requires two hydrogen atom transfers. The accuracy of the predicted mechanisms in describing the hydrogen transfers was confirmed by atoms-in-molecules calculations and natural bond orbital analysis. The calculated results predict that hydrogen transfer process in both reactions at the M06-2X level is favourable from the kinetic and thermodynamic points of view. In the natural bond orbital analysis, the stabilization energy, E(2), delocalization corrections, at the B3LYP level is much higher than the same results at the M06-2X level (nearly twice). The activation thermodynamic parameters show that the first steps of the two reactions have lower barrier energy than the second steps. The Gibbs free energy values estimate that adducts of both the reactions at the mentioned method are spontaneous. The whole reaction of glyoxal + NH2 is more favourable than the whole reaction of glyoxal + NO2. The rate constants were calculated for the mentioned pathways using transition state theory for bimolecular steps and the fitted equations are reported.

中文翻译：

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乙二醛与 NO2 和 NH2 自由基的大气反应：夺氢机制和自然键轨道分析

乙二醛在大气化学中很重要，因为它能够转化为二次有机气溶胶。在本研究中，结合 6-311++G(d,p) 基组，在 B3LYP 和 M06-2X 水平上研究了两种大气活性自由基 NO2 和 NH2 的乙二醛破坏反应。乙二醛与 NO2/NH2 自由基形成最稳定的加合物需要两个氢原子转移。分子中原子计算和自然键轨道分析证实了描述氢转移的预测机制的准确性。计算结果预测，从动力学和热力学的角度来看，M06-2X 水平的两个反应中的氢转移过程都是有利的。在自然键轨道分析中，稳定能 E(2)、离域校正、B3LYP 级别的结果远高于 M06-2X 级别的相同结果（接近两倍）。活化热力学参数表明，两个反应的第一步比第二步具有更低的势垒能。吉布斯自由能值估计上述方法中两种反应的加合物都是自发的。乙二醛+NH2的整体反应比乙二醛+NO2的整体反应更有利。使用双分子步骤的过渡态理论计算了上述途径的速率常数，并报告了拟合方程。吉布斯自由能值估计上述方法中两种反应的加合物都是自发的。乙二醛+NH2的整体反应比乙二醛+NO2的整体反应更有利。使用双分子步骤的过渡态理论计算上述途径的速率常数，并报告拟合方程。吉布斯自由能值估计上述方法中两种反应的加合物都是自发的。乙二醛+NH2的整体反应比乙二醛+NO2的整体反应更有利。使用双分子步骤的过渡态理论计算了上述途径的速率常数，并报告了拟合方程。