HNO自由基与O_2反应机理的理论研究

Theoretical Mechanism Study of the HNO+O_2 Reaction

采用密度泛函理论(DFT)和从头算方法,在B3LYP/6-311++G(d,p)水平上对反应HNO+O_2做了理论计算研究。优化得到了反应物、中间体、过渡态和产物的几何构型以及相应的能量值、振动频率。通过分析反应路径的能量差异,以及异构化难易程度,发现HNO+O_2反应有2种产物通道:HOONO和HNO_3。其中过氧亚硝酸HOONO是主要产物,有3种稳定的构象。

In order to figure out the reaction mechanisms of HNO radical with O2,a detailed theoretical study was performed. Reveal the microscopic reaction mechanism and provide theoretical support for the protection of the air. The geometry configurations of reactants,intermediates,transition states and products were optimized so that their harmonic vibration frequencies and energies were obtained at the B3LYP/6-311G（d, p） level. Intrinsic reaction coordinate calculations at the same level were computed to ensure the connections between transition states and intermediates. The energies were confirmed by single-point calculated at the QCISD/6-311G（d, p）,and all the total energies were corrected by the zero-point energy. Through analyzing the energy and isomerization of the reaction paths,it is found that HNOO2 possesses two products：HOONO and HNO3. HOONO is the main product,and it has three isomers.