Acta Phys. -Chim. Sin. ›› 2013, Vol. 29 ›› Issue (06): 1161-1167.doi: 10.3866/PKU.WHXB201304021

• THERMODYNAMICS, KINETICS, AND STRUCTURAL CHEMISTRY • Previous Articles     Next Articles

Mechanism and Thermodynamic Properties of CH3SO3 Decomposition

CAO Jia1,2, WANG Wen-Liang2, GAO Lou-Jun1, FU Feng1   

  1. 1 College of Chemistry & Chemical engineering, Yan’an University, Yan’an 716000, P. R. China;
    2 Key Laboratory for Macromolecular Science of Shaanxi Province, School of Chemistry &Chemical engineering, Shaanxi Normal University, Xi’an 710062, P. R. China
  • Received:2012-12-17 Revised:2013-04-01 Published:2013-05-17
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (21173139) and Foundation of Shaanxi Education Department (2013JK0667)

Abstract:

The mechanism and kinetics of unimolecular decomposition of CH3SO3 are studied at the G3XMP2//B3LYP/6-311+G(3df,2p) level of theory. Six possible dissociation channels and potential energy surface for the CH3SO3 decomposition are investigated. Rate constants over the temperature range of 200-3000 K are calculated using Rice-Ramsperger-Kassel-Marcus (RRKM) theory. The results indicate that the product P1(CH3+SO3) is dominant between 200-3000 K. Products P2(CH3O+SO2) and P3(HCHO+HOSO) increase significantly at higher temperatures (>3000 K). Products P4(CHSO2+H2O), P5(CH2SO3+H) and P6(CHSO3+H2) show little formation in the temperature range (200-3000 K). The total rate constant can be expressed as ktotal=1.40×1012T0.15exp(7831.58/T). Thermodynamic properties including enthalpies of formation (DfHΘ298 K, DfH0 K), entropies (SΘ298 K), and heat capacities (Cp, 298-2000 K) of all the minima and transition states are predicted from statistical mechanics, and found to be in good agreement with the available experimental values.

Key words: CH3SO3, Decomposition mechanism, Thermodynamic property, Rate constant

MSC2000: 

  • O641