Surface chemistry on transition metal colloids—an infrared and NMR study of carbon monoxide adsorption on colloidal platinum

Abstract Highly dispersed ( 13 C NMR. The chemical shift of the adsorbed CO is 192 ppm, and the absence of a Knight shift is interpreted in terms of a pseudomolecular description of the highly dispersed platinum particles, which are not large enough to exhibit metallic properties. The CO covered colloid is converted by hydrolysis into the molecular platinum carbonyl anion clusters [Pt 3 (CO) 6 ] n 2− , n = 3,4.