Pt AND Pt/Cu CARBONYL CLUSTERS SYNTHESIZED BY RADIOLYSIS

摘要

In the mixed solvent: 50/50% v/v water/2-propanol, [Pt_3(CO)_6]_n~(2-) clusters with n = 3-10 have been obtained by irradiating solutions containing K_2PtCl_4 under 1 atm CO. n is deduced from the very typical UV-visible and IR absorption spectra. The reduction occurs by a combined effect of CO and of the radicals produced by radiolysis (radiocatalysis). The synthesis is selective: the nuclearity n can be chosen by adjusting the dose (high doses yield low n values). Increasing the Pt salt concentration leads to CO-stabilized subcolloid particles. Intermetallic cluster compounds are expected from solutions containing two metal salts: bimetallic Pt/Cu carbonyl clusters have been obtained. Two distinct compounds have been characterized by their UV-visible spectra. Attempts with Pt/Ru and Pt/Sn systems were unsuccessful.