A partially decarbonylated metal cluster is quickly formed on the surface of silica by oxidation at room temperature; it is possible to regenerate the initial cluster compound under a carbon monoxide atmosphere at 200°C. Decarbonylation of Rh6(CO)16 at higher temperature produces a new metallic material on the surface, characterized by two v(CO) vibration bands at 2048 ± 7 cm-1 and 1893 ± 10 cm-1. These two bands have been respectively assigned to a terminal carbonyl group and a bridged carbonyl group bonded to two rhodium atoms. Oxidation of this compound occurs very easily under oxygen at room temperature and gives an oxidized material presumably of the same nuclearity; adsorption of carbon monoxide produces two intense sharp bands at 2093 and 2038 cm-1 which have been assigned to the symmetric and asymmetric stretching modes of two CO molecules bonded to a single oxidized Rh site as RhI(CO)2. The conversion from the oxidized surface species to the metallic one can be performed under mild conditions, but attempts to regenerate the initial cluster compound were unsuccessful.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Organic Chemistry
- Inorganic Chemistry
- Materials Chemistry