HIO3分子的密度泛函理论研究

利用密度泛函理论对于HIO3分子的异构化及其消去反应势能面进行了细致的研究.B3LYP结合混合基组,对于O和H原子使用6-311 G(3df,3pd)基组,对于I原子使用3-21G基组,进行结构优化,振动频率计算以及电子拓扑学分析.在势能面上八个稳定的异构体结构被找到,经过计算稳定性如下:HOIO2-1>HOOOI-2>HOOOI-1>HOIOO-1>HOIOO-2>HOIO2-2>HIO3-1>HIO3-2,此外,势能面上存在三种稳定的松散复合物.对于势能面上IO HO2,OIO OH和IOO OH的反应机理进行了详细的讨论.利用振动模式分析的方法对于反应物,中间体,过渡态以及产物之间的关系进行明确的分析.此外,还应用电子密度拓扑学对于异构化及其消去过程进行分析.

Computational investigation for HIO3 isomers by density function theory

The present study provides the potential energy surface of isomerization and elimination for the HIO3 system by means of DFT methods.The structural optimizations,intrinsic reaction coordinate(IRC) calculations,vibrational mode and electronic density topological analyses were performed at B3LYP level in conjunction with the 6-311 G(3df,3pd) basis set for hydrogen,oxygen and 3-21G basis set for iodine.Eight isomers of relative thermodynamic stability,HOIO2-1>HOOOI-2>HOOOI-1>HOIOO-1>HOIOO2>HOIO2-2>HIO3-1>HIO3-2,have been identified as energy minima,and three loose complexes have been located on the PES besides the covalently bound minima.Isomerization,molecular elimination saddle points have been traced and a qualitative understanding of the mechanism and kinetics of the stratospherically important IO HO2,OIO OH and IOO OH has been derived.Vibrational mode analysis is used to elucidate the relationships of the reactants,the transition states,isomers,the complexes and the products.The breakage and formation of the chemical bonds in the isomerization and elimination processes have also been discussed by the topological analysis method of electronic density.