亚硝酰氢与羟基自由基反应的密度泛函理论研究

A density functional theoretical study of the reaction of HNO with OH radical

用密度泛函理论研究了HNO+OH反应机理。在(U)B3LYP/aug-cc-pVTZ水平上,优化了反应通道上各驻点(反应物、中间体、过渡态和产物)的几何构型,获得了零点能校正后的反应势能曲线。研究表明:根据进攻方式的不同,有3个反应通道,反应通道不同则产物不同。反应的主要产物是NO+H_2O,次要产物是NH_2+O_2;主要产物和次要产物与反应物的总能量之差(经零点能校正后)分别为-133.42 kJ/mol和150.44 kJ/mol。生成主要产物时主要反应通道的活化能为102.11 kJ/mol。

Using the density functional theory （DFT）, the reaction mechanism for the HNO ＋ OH reaction was studied. The geometries of stationary points （reactants, transition states, isomers and productions） were optimized at the （U）B3LYP/aug-cc-pVTZ level. The potential energy surfaces （PES） for the HNO ＋ OH reaction were obtained with the corrections of zero-point vibrational energies. The calculated results suggested that the attacking way of the OH radical to HNO have three pathways. NO ＋ H2O is the main product by the analysis of the change of the HNO ＋ OH reaction energies and NH2 ＋ O2 is the secondary product. The relative energies of the main and secondary products with respect to that of the reactants are - 133.42 kJ/mol and 150.44 kJ/mol, respectively. The activation barrier of the dominant reaction pathway was predicted to be 102.11 kJ/mol.