Rankin Rees B, Sholl David S
Department of Chemical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA.
J Chem Phys. 2006 Feb 21;124(7):74703. doi: 10.1063/1.2168440.
Adsorption of amino acids on Cu(100) is known experimentally to induce surface reconstructions featuring intrinsically chiral Cu(3,1,17) facets, but no information about the geometry of the molecules on these chiral facets is available. We present density-functional theory calculations for the structure of glycine and alanine at moderate coverages on Cu(3,1,17). As might be expected, molecules prefer to bind at the step edges on this surface rather than on the surface's (100)-oriented terraces. The adsorption of enantiopure alanine on Cu(3,1,17) is predicted to be weakly enantiospecific, with S-alanine being more stable on Cu(3,1,17)(S) than R-alanine. By comparing the surface energies of Cu(100) and Cu(3,1,17) in the presence of adsorbed glycine or alanine, our calculations provide insight into the driving force for chiral reconstructions of Cu(100) by amino acids.
实验表明，氨基酸在Cu(100)上的吸附会诱导表面重构，形成具有固有手性的Cu(3,1,17)晶面，但目前尚无关于这些手性晶面上分子几何结构的信息。我们给出了甘氨酸和丙氨酸在Cu(3,1,17)上中等覆盖度时结构的密度泛函理论计算结果。正如预期的那样，分子更倾向于在该表面的台阶边缘而非(100)取向的台面上结合。预测对映体纯的丙氨酸在Cu(3,1,17)上的吸附具有弱对映体特异性，S-丙氨酸在Cu(3,1,17)(S)上比R-丙氨酸更稳定。通过比较存在吸附的甘氨酸或丙氨酸时Cu(100)和Cu(3,1,17)的表面能，我们的计算为氨基酸对手性Cu(100)重构的驱动力提供了见解。
