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在HF/LANL2DZ水平上,采用能量梯度法,研究了铑碘催化剂催化甲醇羰基化反应循环中各基元反应的反应物、中间体、过渡态、产物的几何结构,并计算了它们势能面的变化。通过对各基元反应过渡态的IRC解析,证实了所得各类几何结构是甲醇羰基化锗碘催化循环反应途径上的驻点,完整给出了循环反应过程中分子沿极小能量途径在各基元反应过程中的构型变化,并提出了中间体构型转换在循环反应过程中的作用。通过结构分析,提出了顺式和反式催化循环反应两种途径之间除催化活性物顺反异构关联外,还可以通过中间体构型转换关联,其活化能为49.79kJ/mol,并且在还原消除基元反应步骤有既非顺式也非反式的情况,证明该循环反应可能经历多个途径实现,但无论何种途径,碘甲烷氧化加成基元反应是整个循环反应过程的速控步骤。
At the level of HF / LANL2DZ, the energy gradient method was used to study the geometrical structures of the reactants, intermediates, transition states and products of each elementary reaction catalyzed by rhodium iodide catalyst in the carbonylation reaction of methanol, and their potential energy surface Variety. Through the IRC analysis of the transition states of each elementary reaction, it is confirmed that the geometrical structures obtained are the stagnation points on the catalytic reaction pathway of germanium carbonyloiodide iodide, and the molecular path along the minimum energy in the cycle reaction The conformational changes during the elementary reaction are also discussed. The role of the intermediate configuration transition in the cyclic reaction is also proposed. According to the structural analysis, the cis-trans and trans-catalyzed cyclic reactions are proposed. In addition to the cis-trans and trans-transamination, the activation energy is 49.79kJ / mol In the reductive elimination motif reaction step there is neither cis nor trans, proving that the cyclic reaction may go through several ways, but whatever the route, the methyl iodide oxidation adduct reaction is the entire cycle of the reaction Speed control steps.