【摘要】 用密度泛函DFT(B3LYP)方法和MP2从头算方法,在6-311G(d,p),6-311++G(d,p)基组水平上研究了CO+HO2=CO2+OH,CO+NO2=CO2+NO 2个反应的过渡态结构和反应机理,沿IRC分析指出反应均为协同完成的一步反应.同时计算了2个反应的活化位垒和反应焓变,并与实验估计值进行了比较.对CO与HO2的反应采用MP2/6-311++G(d,p)方法,计算所得反应位垒为100.98 kJ/mol,与实验估计值93.60 kJ/mol基本接近,对CO与NO2的反应采用B3LYP/6-311++G(d,p)方法,计算所得反应位垒为115.99 kJ/mol,比实验估计值141.51 kJ/mol低25.52 kJ/mol.计算同时表明2个反应均为放热反应.更多还原

【Abstract】 The reaction mechanism of reactions CO+HO2=CO2+OH(1) and CO+NO2=CO2+NO(2) was theoretically studied with DFT(B3LYP) and MP2.The geometry and energy of reactants,transitional states and products were optimized at the 6-311G(d,p) and 6-311++G(d,p) levels.Based on IRC,the calculated results indicated that reaction(1) and(2) are all the concerted one-step processes.The energy barrier and enthalpy for the reactions were also calculated and compared with experimental findings.The energy barrier of the reaction(1) was 100.98 kJ/mol by using MP2/6-311++G(d,p).The difference is less between the value and the experimental value 96.30 kJ/mol.And the reaction(2) was 115.99 kJ/mol by using B3LYP/6-311++G(d,p),with the experimental value 141.51 kJ/mol only differs 25.52 kJ/mol.The results showed that both the reactions were the exothermal.更多还原