文献类型：期刊文献

英文题名：Theoretical study on the structure, vibrational frequency and thermodynamic properties of 2,3,7,8-tetrachlorinated dibenzo-p-dioxin

作者：Liu, GS; Yu, JG

机构：[1]Jiangxi Sci & Technol Normal Univ, Dept Chem, Nanchang 330013, Peoples R China;[2]E China Univ Chem Technol, LRUE, Shanghai 200237, Peoples R China

年份：2005

卷号：717

期号：1-3

起止页码：15

外文期刊名：JOURNAL OF MOLECULAR STRUCTURE-THEOCHEM

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000228024900004)】；

语种：英文

外文关键词：2,3,7,8-tetrachlorinated dibenzo-p-dioxin (TCDD); density functional theory (DFT); semi-empirical molecular orbital method; PM3 Hamiltonian

摘要：In this paper, semi-empirical molecular orbital method with the PM3 Hamiltonian was used to study the geometrical optimization and thermodynamic parameters of heats of formation, standard entropy, standard enthalpy, heat capacity of 2,3,7,8-tetrachlorinated dibenzo-p-dioxin (TCDD). Density function theory (DFT) method was also employed to further optimize the molecular geometry of 2,3,7,8-TCDD at B3LYP/6-31G, B3LYP/6-31G*, B3LYP/6-311G* and MP2/6-31G* levels, respectively. Harmonic vibrational spectrum have been performed at B3LYP/6-31G* and B3LYP/6-311G* levels. The standard thermodynamic properties at various temperatures have been evaluated using the scaled B3LYP/6-31G* and B3LYP/6-311G* frequencies. Calculated results are compared with each other and with available experimental data, and are discussed in detail. (c) 2004 Elsevier B.V. All rights reserved.