title: Theoretical Investigation of Mono- and Di-Chloro-Substitient Effects on the Insulation and Greenhouse Properties of Octafluorocyclobutane.
abstract: Octafluorocyclobutane,c-C4F8, and its derivatives are regarded as promising replacements of insulation gaseous SF6, which are currently widely used in electric equipment but suffer greatly from its greenhouse effect. Based on the recent finding that the dielectric and thermodynamics properties of insulating gases are greatly dependent on the molecule's microscopic electronic and vibrational parameters, in this work, we use density functional theory (DFT) to study the molecular structures, electron affinities, and IR-active vibrational frequencies as well as thermodynamic properties forc-C4F8and a series of mono-, di-substitutedc-C4F8compounds. It is shown that DFT calculation of perfluoro-compounds is sensitive to the chosen functional. Although all chloro-substitutedc-C4F8molecules are found to have much larger electron affinities, only part of them have less IR intensity in the atmospheric IR "window" thanc-C4F8. Such a study provides useful guideline for the pre-screening search for new insulation gases via electronic structure calculations.
authors.affiliation: College of Electrical and Electronic Engineering, Huazhong University of Science and TechnologyWuhan, China; State Grid Electric Power Research InstituteWuhan, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Cheng
authors.affiliation: State Grid Electric Power Research InstituteWuhan, China; School of Electrical Engineering, Wuhan UniversityWuhan, China.
authors.forename: Zhaoyu
authors.initials: Z
authors.lastname: Qin
authors.affiliation: State Grid Electric Power Research Institute Wuhan, China.
authors.forename: Chaohai
authors.initials: C
authors.lastname: Zhang
authors.affiliation: College of Electrical and Electronic Engineering, Huazhong University of Science and TechnologyWuhan, China; State Grid Electric Power Research InstituteWuhan, China.
authors.forename: Huixuan
authors.initials: H
authors.lastname: Shi
authors.affiliation: State Grid Electric Power Research Institute Wuhan, China.
authors.forename: Kun
authors.initials: K
authors.lastname: Zhao
authors.affiliation: School of Chemistry and Chemical Engineering, Nanjing University Nanjing, China.
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Xie
authors.affiliation: School of Chemistry and Chemical Engineering, Nanjing University Nanjing, China.
authors.forename: Haibo
authors.initials: H
authors.lastname: Ma
keywords: density functional theory; electron affinity; insulating gas; octafluorocyclobutane; vibrational frequency