中文关键词:氢气生物学效应活性氧化物反应机理轨道组成 英文关键词:HydrogenBiological effectActive oxideReaction mechanismOrbital composition 基金项目:河北省高等学校科学技术研究青年基金项目（QN2014312）和唐山师范学院科学研究基金项目（2017B02）资助

作者	单位
孟祥军	唐山师范学院化学系 唐山 063000
王秀阁	唐山师范学院化学系 唐山 063000
和芹	唐山师范学院化学系 唐山 063000
王磊	唐山师范学院化学系 唐山 063000

摘要点击次数:886 全文下载次数:0 中文摘要: 为了认识氢气生物学效应的分子机制，采用量子化学的M06-2X/6-311+G（d，p）和CCSD（t）/aug-cc-pVTZ方法模拟了人体条件（310K、液相）下氢分子与超氧阴离子自由基的反应机理。研究表明，反应的吉布斯自由能变化值为117.2kJ·mol^-1，活化自由能垒为156.2kJ·mol^-1，从热力学及动力学角度该反应都不容易进行。然后从电子结构和轨道作用层面对反应的微观机制进行了探讨，发现从反应物变为过渡态过程中，复合物轨道的组成和轨道能级发生显著变化（尤其是第8号轨道能级升高最多，达到2.73eV），O₂^-片段向H₂片段的电子转移数增加了0.1760个，并且转移的电子主要集居于第8号轨道，这削弱了H₂片段两个H原子间的化学键，也是反应活化能的主要来源。 英文摘要: In order to understand the molecular mechanism of biological effects for hydrogen, M06-2X/6-311+G(d,p) and CCSD(t)/aug-cc-pVTZ methods were used to simulate the reaction of hydrogen molecules with superoxide anion free radicals under the conditions of human body (310 K, liquid phase). It was found that the variation value of Gibbs free energy and the barrier of activation free energy for the reaction were 117.2 kJ·mol^-1 and 156.2 kJ·mol^-1, respectively, indicating that the reaction is not easy to proceed either from a thermodynamic or kinetic perspective. Besides, the microscopic mechanism of the reaction was discussed from the level of electronic structure and orbital interaction. The results showed that both the orbital composition and the orbital energy level of the complex changed significantly during the transition from reactant to transition state (especially the energy level of the eighth orbital increased the most, reaching to 2.73 eV). The number of electron transfer from the fragment O₂^- to the fragment H₂ increased by 0.1760, and the transferred electrons were mainly concentrated in the eighth orbital, which weakened the chemical bond between the two H atoms of the fragment H₂ and was also the main source of activation energy for the reaction. 查看全文查看/发表评论下载PDF阅读器 相关附件：附件1-修改说明版权转让声明书 -->