【摘要】 用EHMO方法计算Ni(111)面和Cu(111)面吸附乙烯分子的几何构型、键连能和活化能。结果表明,Ni吸附的稳定构型为C—C,键长l=1.60、C—C键与金属面距离h=1.80,HCH面向上弯曲角θ=30°;Cu吸附的h=1.70,l=1.94,θ=60°。两个体系的键连能分别为260.8和89.5kJ/mol。讨论了键连能差异并用MO自然相关法解释了不同吸附能力。更多还原

【Abstract】 The stable geometries, the bonding energies and the activation energies are calculated for ethylene adsorption on transition metal Ni(111) and Cu(111) surfaces by using EHMO method. The results show that the C-C bond length, 1 = 1.60A, the perpendicular distance between the C-C bond and the metal surface, h = 1.80A and the bend up angle of the plane HCH, θ=30° for the Ni adsorption) and l= 1.94A,h=1.70A and θ=60° for the Cu adsorption. The corresponding bonding energies for two systems are 62.1 and 21.3 kcal/mol, respectively. These results are consistent with the experimental fact. The origins of the different bonding energies are discussed and the origins of the different values for the activition energies are explained by molecular orbital natural correlation.更多还原