CH_3NO_2在Cu(111)面吸附态的研究

A STUDY OF THE CHEMISORPTION OF CH_3NO_2 ON Cu(lll) SURFACE

用CNDO/2半经验量化计算方法对CH_3NO_2分子在Cu(111)面四个吸附位上25种吸附态进行了优化计算,得到以CH_3NO_2分子中的-NO_2取向吸附在Cu(111)面的桥位上,且CH_3NO_2分子中的ONO面与Cu-Cu键成60°时为最稳吸附态。计算得到的这一稳定吸附态的吸附取向和吸附体系的态密度结果与我们的实验结果是一致的;从吸附态的轨道成分分析表明,吸附是通过CH_3NO_2分子中O原子的2p轨道与Cu的3d轨道相互作用。

The chemisorption of CH3NO2 on Cu(111) surface has been studied by the semiempirical quantum mechanical method (CNDO/2) of cluster models. The results indicate that the bridge site of Cu(111) is preferable for CH3NO2 adsorption, the orientation of CH3NO2 adsorption is that 桸O2 points downward to the Cu surface, and the angle between the plane ONO and Cu-Cu bond is 60? The orientation of adsorption and the density of states calculated by CNDO/2 calculation are in agreement with the experimental results. The analyses of atomic orbital percentages show that CH3NO2 adsorption is the result of interaction of 2p atomic orbitals of 0 for CH3NO2 with 3d atomic orbitals of Cu.