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


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)


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