铂与氢、水和苯分子相互作用的量子化学研究

THE QUANTUM CHEMISTRY STUDY ON INTERACTION OF PLATINUM, HYDROGEN,WATER AND BENZENE

采用量子化学程序Gaussian 98(A .9)从头算的B3LYP方法 ,全优化计算铂对氢、水和苯的化学吸附作用 ,得到了 3种相关络合物PtX、PtXX和PtXXX (X =H ,H2 O或C6H6)的平衡几何构型和电子结构信息 ,并探讨了这些络合物的成键性质 ,以及苯环与铂原子之间的分子轨道作用性质。结果表明 ,苯环与铂原子之间有很强的成键作用 ,并随着游离氢原子和水分子的参与 ,作用强度有很大变化。苯分子吸附在金属铂上 ,它的芳香性得到不同程度的降低 ,苯环被活化 ,苯环与铂原子之间形成 η2 型π键络合物 ;水参与作用后 ,苯环与铂原子之间形成σ络合物 ;氢和水同时参与作用后 ,苯环与铂原子之间仅有很弱的π轨道作用。

The chemical adsorption of benzene,water and hydrogen on platinum was studied by using B3LYP,an initio method from Gausssian 98 program (A.9 version). The equalization geometric configurations and related electronic structural information about the three complexes PtX,PtXX,PtXXX (X=H,H 2O or C 6H 6) were worked out. The bond properties of these complexes and the bonding interaction were also discussed. It was found that there existed a strong bonding interaction between Pt and benzene,and the bonding strength changed with the participation of hydrogen and water. The aromaticity of the adsorbed benzene molecules on Pt was greatly reduced,the benzene ring was activated to form the η 2 type π complex with Pt. When water took part in the interaction,the σ complex was formed between Pt and benzene,but only weak π orbital interaction was formed when both water and hydrogen participated in the interaction.