Study On Physical Properties Of Five Fluoride Molecules Under External Electric Field

With the continuous development of society and economy,more and more countries have begun to pay attention to the global impact caused by environmental pollution.As one of the major pollution sources,fluorine pollution has attracted more and more scholars’ attention.Under the action of external electric field,molecules will undergo a series of physical and chemical changes,such as the generation of new free radicals,the breaking of chemical bonds and the generation of new excited states.The study of physical and chemical properties of molecules under external electric field has been successfully applied to many fields such as environmental science,biology,medicine,materials science and so on.In this paper,Gaussian09 quantum chemistry software is used to simulate and optimize the ground state geometric structures of potassium fluoride,4-fluorophenol,nitrogen trifluoride,sulfuryl fluoride and o-fluoroaniline,and the geometric configuration,spectral characteristics and dissociation characteristics of the molecules are studied by applied electric field.1.DFT-LSDA/6-311 G basis set was selected to study the bond length,energy,dipole moment,energy level distribution and infrared spectrum of potassium fluoride.The results show that with the increase of the reverse electric field intensity,the molecular potential barrier gradually decreases,and the potential energy curve is flat and the molecules tend to dissociate at the electric field intensity of 0.02 a.u..2.Using DFT-B3LYP/6-311G+2d2p basis set to study the characteristics of 4-fluorophenol molecules,the results show that with the increase of electric field intensity,the potential energy curve decreases,and at 0.03 a.u.electric field intensity,the potential energy curve is flat and the molecules tend to dissociate.3.DFT-B3LYP/6-311 Gdp method and basis set were selected to study the geometric configuration,spectral characteristics and dissociation characteristics of o-fluoroaniline.The results show that the potential energy curve of o-fluoroaniline decreases and tends to dissociate under the electric field intensity of 0.05 a.u..4.Using DFT-B3LYP/6-311G+dp basis set to simulate the applied electric field of nitrogen trifluoride molecules,the results show that Zeeman effect occurs in the infrared spectrum of nitrogen trifluoride molecules under the action of external electric field.Under the electric field intensity of 0.05 a.u.,the dissociation of nitrogen trifluoride molecules will occur.When the electric field intensity is increased to0.09 a.u.,the nitrogen trifluoride molecules will undergo synergetic dissociation.4.Selecting DFT-LSDA/6-311G3d3 p basis set level,the properties of sulfuryl fluoride molecules were studied by external electric field.The geometric configuration,spectral characteristics and dissociation characteristics of sulfuryl fluoride molecules have changed obviously.Under the electric field intensity of0.08 a.u.,one of the S-F bonds of sulfuryl fluoride molecules will break,and after the electric field is increased to 0.1a.u.,the double S-F bonds will co-dissociate.Through the calculation and analysis of the above five kinds of fluoride molecules,it provides ideas for external electric field degradation of fluoride,and also provides theoretical reference for experimental external electric field degradation.