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International Journal of Chemical Engineering
Volume 2008, Article ID 938645, 6 pages
http://dx.doi.org/10.1155/2008/938645
Research Article

DFT Calculation on 76 Polychlorophenazines: Their Thermodynamic Function and Implication of Cl Substituted Position

1Department of Environment, Nanjing University, Nanjing 214007, Jiangsu, China
2School of Biological and Chemical Engineering, Jiaxing University, Jiaxing 314001, Zhejiang, China

Received 18 April 2008; Revised 1 August 2008; Accepted 10 September 2008

Academic Editor: Z. Zhang

Copyright © 2008 Hong-Xia Yu et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Thermodynamic functions, including enthalpy () and entropy () for 76 polychlorophenazines (PCPZs) in the gas state at 298.15 K and 101.325 kPa, have been calculated using the B3LYP/6-31 level with Gaussian 03 program, and considered on solvation affects. Total free energy in water () was calculated with the same program. Based on these data, the isodesmic reactions were designed to calculate the standard formation heat () and standard free energy of formation in water . The dependences of these thermodynamic parameters on the numbers and positions of chlorine substitution () were discussed. It is suggested that , and of PCPZs varied greatly with . Moreover, the values of molar heat capacity at constant pressure () from 200 to 1800 K for PCPZ congeners were calculated using a statistical thermodynamics calculation program based on Gaussian output files, and the temperature-dependence relation of was obtained using the least-squares method. In addition, according to the relative magnitude of their , the relative stability order of PCPZ congeners was theoretically proposed.