Spectrum And Dissociation Characteristics Of Halogenated Compounds Under External Electric Field

Halogen elements are one of the organic pollutants that threaten the ozone layer.Studying the dissociation characteristics of halogen element molecules under the action of an external electric field has important reference value for the protection of the ozone layer.By studying the geometric properties and spectral properties of the molecular ground state,we can guess the dissociation properties of the molecule,and then scan the molecular potential energy curve and potential energy surface to find direct evidence of the molecular dissociation properties.The electric field degradation mechanism is of great significance.In order to elucidate the generation mechanism of halogen element radicals and understand their influence on the atmospheric environment,it is necessary to study the dissociation kinetics of halogen element molecules under the action of an external electric field.This paper uses Gaussian09 quantum computing software to simulate molecules.The main work is divided into the following parts:The first part is the dissociation of cesium bromide and 4-bromophenol molecules.The ground state geometric parameters,spectral properties and two-body dissociation of cesium bromide and 4-bromophenol molecules were calculated by Semiempirical/PM6 and B3LYP/6-311+G（d,p）methods under different external electric fields,respectively characteristic.With the enhancement of the external electric field,the energy gaps of both cesium bromide and 4-bromophenol molecules decrease,and both molecules become more active.Scanning the potential energy curves of the two molecules found that the external electric field with a strength of-0.015 a.u.broke the Cs-Br bond of the cesium bromide molecule.When the external electric field strength was 0.03 a.u.,the C-Br bond of the 4-bromophenol molecule was broken,so the bromine Both cesium and 4-bromophenol molecules undergo dissociation.The second part is the stepwise dissociation of the fluorochlorocarbonyl molecule.The ground state geometry,spectral properties and stepwise dissociation properties of chlorofluorocarbon molecules under different external electric fields were optimized and calculated at the B3LYP/6-31G（d）basis set level by density functional method.With the increase of the external electric field,the energy gap of the chlorofluorocarbon molecule first increases and then decreases,which enhances the activity of the molecule.From the potential energy curve of the C-Cl bond and the molecular potential energy surface,it is found that when the external electric field strength is 0.03 a.u.,the C-Cl bond is broken,when the external electric field strength is-0.005 a.u.,the molecular CCl and CF bonds are broken,and the three-body gradual dissociation occurs.The third part is the cooperative dissociation of p-dibromo benzene and aluminum chloride molecules.Density functional theory was used to calculate p-dibromo benzene and aluminum chloride molecules under different external electric fields at the B3LYP/6-311+G（d,p）and B3LYP/6-31+G（d）basis set levels,respectively.The ground state geometry and spectral properties of,and finally,the dissociation properties of aluminum chloride molecules are directly given by calculating the molecular potential energy curve and potential energy surface.The energy gap of p-dibromo benzene and aluminum chloride molecules decreases with the enhancement of the external electric field,both molecules become more active,and the bonds connected to the bromine atoms are more easily broken.When the external electric field strength is 0.02 a.u.,the two C-Br bonds of the p-dibromo benzene molecule are gradually broken,and the threebody gradual dissociation phenomenon occurs.Under the same external electric field,another dissociation channel appears in the molecule,which may occur cooperative dissociation.Leave.When the external electric field strength is 0.04 a.u.,the 1Al-4Cl bond of the aluminum chloride molecule is broken;when the external electric field strength is 0.045 a.u.,another dissociation pathway appears in the aluminum chloride molecule,and synergistic dissociation may occur.