Facet-selective adsorption on noble metal crystals guided by electrostatic potential surfaces of aromatic molecules

J Am Chem Soc. 2013 Oct 16;135(41):15489-500. doi: 10.1021/ja406018u. Epub 2013 Oct 4.

Abstract

We aim to provide a model platform composed of aromatic molecules and noble metal surfaces to study the molecular facet-selective adsorption and employ the discoveries to design surfactants for predictable shape-controlled syntheses of nanocrystals. Starting from Pt, it is demonstrated that negative electrostatic potential on the aromatic ring is the prerequisite to display binding selectivity to Pt(111), while a neutral to positive one prefers Pt(100). The geometric matching between molecular binding sites and surface lattices plays a role as well in facet selectivity. Significantly, Raman spectroscopy has been employed to probe the interactions between aromatic molecules and metal surfaces, providing direct evidence of their binding mechanisms. These discoveries are further exploited to design and identify Pd(111) and Pd(100) facet-specific surfactants. These results represent a step forward in achieving predictable and programmable nanostructures through better understanding of organic-inorganic interfaces.