In this paper, the reaction mechanism of HOCO with its radical has been investigated deeply by density functional theory(DFT), while the geometries and harmonic vibration frequencies of the reactants, intermediates, t...In this paper, the reaction mechanism of HOCO with its radical has been investigated deeply by density functional theory(DFT), while the geometries and harmonic vibration frequencies of the reactants, intermediates, transition states and products have been calculated at the B3LYP/6-311++G** level. The CCSD(T)/cc-p VQZ method was used to further calculate the single-point energy of each stationary point along the reaction channel. The result shows that channels(b) and(d) via carbon-carbon intermediates are competing with the ones(e),(f),(i) and(l) through carbon-oxygen intermediates, and the six channels are dominant for the title reaction to produce HCOOH and CO2. The result also indicates that the hydrogen abstraction from the HOCO radical can be performed quickly by the self-interaction of HOCO in the absence of other radicals or atoms, which indirectly proves for the first time that the ground-state cis-HOCO radical is not decomposed by the tunneling effect. In addition, the charges of natural population analysis(NPA) and the variation of chemical bonds have been analyzed by the Natural Bond Orbital(NBO) method along with the important reaction path.展开更多
基金supported by the National Natural Science Foundation of China(50673085,20677053)the Basic Research Programs of Qingdao Science and Technology Plan(No.13-1-4-233-jch)
文摘In this paper, the reaction mechanism of HOCO with its radical has been investigated deeply by density functional theory(DFT), while the geometries and harmonic vibration frequencies of the reactants, intermediates, transition states and products have been calculated at the B3LYP/6-311++G** level. The CCSD(T)/cc-p VQZ method was used to further calculate the single-point energy of each stationary point along the reaction channel. The result shows that channels(b) and(d) via carbon-carbon intermediates are competing with the ones(e),(f),(i) and(l) through carbon-oxygen intermediates, and the six channels are dominant for the title reaction to produce HCOOH and CO2. The result also indicates that the hydrogen abstraction from the HOCO radical can be performed quickly by the self-interaction of HOCO in the absence of other radicals or atoms, which indirectly proves for the first time that the ground-state cis-HOCO radical is not decomposed by the tunneling effect. In addition, the charges of natural population analysis(NPA) and the variation of chemical bonds have been analyzed by the Natural Bond Orbital(NBO) method along with the important reaction path.
