Key Laboratory of Coal Science and Technology of Ministry of Education and Shanxi Province, Taiyuan University of Technology, Taiyuan 030024, China.
J Mol Model. 2012 Apr;18(4):1255-62. doi: 10.1007/s00894-011-1155-8. Epub 2011 Jul 7.
The detailed mechanisms of the hydrolysis of carbonyl sulfide (OCS) by nucleophilic water and hydroxide ion in both the gas phase and bulk water solvent have been investigated using density functional theory. Various reaction channels on the potential surface have been identified. The thermodynamic results demonstrate that the hydrolysis of OCS by nucleophilic water and hydroxide ion should proceed more favorably at low temperature. The hydrolysis of OCS by the hydroxide ion is the main reaction channel from thermodynamic and kinetic perspectives, and the bulk solvent can influence the rate-determining step in this channel. However, the solvent barely modifies the activation energy of the rate-determining step. For the hydrolysis of OCS by nucleophilic water, the solvent does not modify the rate-determining step, and the corresponding activation energy of the rate-determining step barely changes. This bulk solvent effect suggests that most of the contribution of the solvent is accounted for by considering one water molecule and a hydroxide ion.
采用密度泛函理论研究了亲核水和氢氧根离子在气相和水体溶剂中催化羰基硫（OCS）水解的详细反应机制。在势能表面上确定了各种反应通道。热力学结果表明，亲核水和氢氧根离子催化 OCS 水解在低温下更有利。从热力学和动力学角度来看，氢氧根离子催化 OCS 水解是主要的反应通道，而体相溶剂可以影响该通道中的速率决定步骤。然而，溶剂对速率决定步骤的活化能几乎没有影响。对于亲核水催化 OCS 水解，溶剂不改变速率决定步骤，相应的速率决定步骤的活化能几乎不变。这种体相溶剂效应表明，溶剂的大部分贡献可以通过考虑一个水分子和一个氢氧根离子来解释。
