Bagus Paul S, Hermann Klaus, Wöll Christof
Department of Chemistry, University of North Texas, Denton, Texas 76203-5070, USA.
J Chem Phys. 2005 Nov 8;123(18):184109. doi: 10.1063/1.2107647.
The electronic interaction of two molecules, the aromatic benzene (C6H6) and the saturated hydrocarbon cyclohexane (C6H12) with a Cu(111) surface, have been determined using precise, ab initio electronic structure calculations. For the interaction of these adsorbates with the substrate, we present a detailed analysis and decomposition of various individual chemical mechanisms that contribute. A novel aspect of this analysis is the use of charge-density difference contour plots to graphically display the chemistry. A wave-function-based approach was used in order to avoid problems when the presently most commonly employed approach, density-functional theory, is applied to weakly chemisorbed molecules, where the interaction is dominated by van der Waals forces. The present information are not only relevant with regard to understanding the chemistry going on when molecules are adsorbed on a Cu surface but also have important consequences with regard to charge injection in molecular electronic devices, e.g., organic field-effect transistors and organic light-emitting diodes.
利用精确的从头算电子结构计算，已确定了两种分子，即芳香苯（C6H6）和饱和烃环己烷（C6H12）与Cu(111)表面的电子相互作用。对于这些吸附质与基底的相互作用，我们对各种起作用的单个化学机制进行了详细分析和分解。该分析的一个新颖之处在于使用电荷密度差等高线图来直观展示化学反应。为了避免在将目前最常用的方法——密度泛函理论应用于弱化学吸附分子（其相互作用以范德华力为主）时出现问题，采用了基于波函数的方法。目前的信息不仅与理解分子吸附在铜表面时发生的化学反应相关，而且对于分子电子器件（如有机场效应晶体管和有机发光二极管）中的电荷注入也具有重要意义。
