標題: Calculation of anharmonic effects in the unimolecular dissociation of M2+ (H2O)(2) (M = Be, Mg, and Ca)
作者: Li, Qian
Yao, Li
Xia, Wenwen
Lin, S. H.
應用化學系
Department of Applied Chemistry
關鍵字: anharmonic effect;unimolecular reaction;rate constant;Rice-Ramsperger-Kassel-Marcus (RRKM) theory
公開日期: 17-十一月-2015
摘要: The anharmonic and harmonic rate constants of the unimolecular dissociation of M2+(H2O)(2) (M = Be, Mg, and Ca) were calculated using the Rice-Ramsperger-Kassel-Marcus theory. The anharmonic effects of the reactions were investigated. The results show that the energy barrier of the dissociation of Be2+(H2O)(2) is 68.47 kcal/mol, and the anharmonic (T-4000K = 4.28x10(8) s(-1)) and harmonic (T-4000K = 4.22x10(8) s(-1)) rate constants were close in value in both the canonical and microcanonical systems. The energy barriers of the two steps for the dissociation, Mg2+(H2O)(2) MgOH++H3O+, were 37.41 and 11.39 kcal/mol, and those for the dissociation, Ca2+(H2O)(2) CaOH++H3O+, were 21.15 and 26.42 kcal/mol. The anharmonic effect of the two reactions is significant and cannot be neglected in both the canonical and microcanonical systems. The comparison also shows that the rate constants of the dissociation of Ca2+(H2O)(2) have the maximum values, while those of Be2+(H2O)(2) have the minimum values in the three reactions; however, the anharmonic effect also shows the similar trend in the comparison.
URI: http://dx.doi.org/10.1080/00268976.2015.1036148
http://hdl.handle.net/11536/129377
ISSN: 0026-8976
DOI: 10.1080/00268976.2015.1036148
期刊: MOLECULAR PHYSICS
Volume: 113
Issue: 22
起始頁: 3480
結束頁: 3494
顯示於類別:期刊論文