1. DFT Calculation on 76 Polychlorophenazines: Their Thermodynamic Function and Implication of CI Substituted Position.
- Author
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Hong-Xia Yu, Hui Liu, Zun-Yao Wang, and Lian-Sheng Wang
- Subjects
ENTROPY ,THERMODYNAMICS ,HEAT ,THERMAL expansion ,INSULIN derivatives ,CHLORINE ,GAUSSIAN processes - Abstract
Thermodynamic functions, including enthalpy (H
θ ) and entropy (Sθ ) for 76 polychlorophenazines (PCPZs) in the gas state at 298.15 K and 101.325 kPa, have been calculated using the B3LYP/6-31G* level with Gaussian 03 program, and considered on solvation affects. Total free energy in water (Gw ) was calculated with the same program. Based on these data, the isodesmic reactions were designed to calculate the standard formation heat (Δf Hθ ) and standard free energy of formation in water (Δf Gw θ ). The dependences of these thermodynamic parameters on the numbers and positions of chlorine substitution (NPCS ) were discussed. It is suggested that Sθ , Δf Hθ , and Δf Gw θ of PCPZs varied greatly with NPCS. Moreover, the values of molar heat capacity at constant pressure (Cp,m ) 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 Cp,m was obtained using the least-squares method. In addition, according to the relative magnitude of their Δf Gw θ , the relative stability order of PCPZ congeners was theoretically proposed. [ABSTRACT FROM AUTHOR]- Published
- 2008
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