We performed density-functional calculations aimed to investigate the adsorption mechanism of a single pyridine (C5H5N) molecule on Cu(110) and Ag(110) surfaces. Our ab initio simulations show that, in the ground state, the pyridine molecule adsorbs with its molecular plane perpendicular to these substrates and is oriented along the [001] direction. In this case, the bonding mechanism involves a sigma bond through the lone-pair electrons of the nitrogen atom. When the heterocyclic ring is parallel to the surface, the bonding takes place via pi-like molecular orbitals. However, depending on the position of the N atom on the surface, the planar adsorption configuration can relax to a perpendicular geometry. The role of the long-range van der Waals interactions on the adsorption geometries and energies was analyzed in the framework of the semiempirical method proposed by Grimme [J. Comput. Chem. 27, 1787 (2006)]. We demonstrate that these dispersion effects are very important for geometry and electronic structure of flat adsorption configurations.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据