Theoretical Studies on the Molecular Structures and Thermodynamic Properties of Polychlorinated Fluoranthenes |
| |
Authors: | ZENG Xiao-Lan② WANG Hong-Jun WANG Yan WANG Hui-Juan |
| |
Affiliation: | College of Chemistry and Chemical Engineering,Xinyang Normal University, Xinyang 464000, China |
| |
Abstract: | DFT-B3LYP/6-311G** method has been used to optimize molecular geometric structures of 527 polychlorinated fluoranthene(PCFRT) congeners and calculate their thermo-dynamic properties in the ideal gas state,such as heat capacity at constant volume(Cv),entropy(S),standard enthalpy of formation(ΔfH) and standard Gibbs free energy of formation(ΔfG).The relations of Cv,S,ΔfH and ΔfG with the number and position of chlorine atoms have also been explored,from which the relative stability of PCFRT congeners was theoretically proposed according to the magnitude of the relative standard Gibbs free energy of formation(Δr,fG).It was found that some of the PCFRT isomers are in a nonplanar configuration and there are intramolecular Cl…Cl weak interactions in some of the isomers.With increasing the number of chlorine atoms,the values of ΔfH and ΔfG of the most stable PCFRT isomers decrease initially and then increase.The values of ΔfH and ΔfG of PCFRT congeners with the same number of chlorine atoms show a strong dependence on the positions of chlorine atoms.The relative thermodynamic stability of PCFRT isomers is determined mainly by intramolecular adjacent Cl…Cl nuclear repulsive interaction between Cl atoms at two different six-membered rings.Most PCFRT congeners are easier to form thermodynamically than their parent compound. |
| |
Keywords: | polychlorinated fluoranthene(PCFRT) molecular structure thermodynamic property relative stability density functional theory(DFT) |
本文献已被 CNKI 维普 万方数据 等数据库收录! |
|