Abstract

Upon reduction of N(PPh)OsHgC(CO)(= 2 or 3) with sodium diphenylketyl in tetrahydrofuran a hexaanionic cluster{,} OsHgC(CO){,} is generated which could only be partially characterised by IR spectroscopy as well as through its chemical reactivity. After chromatographic work-up the tetraanionic cluster OsHgC(CO) was isolated as the exclusive reaction product. This was also obtained in low yield (20-30%) by thermolytic degradation of OsHgC(CO) in CHCl. As a consequence of traces of HCl in the CHCl as well as degradation of the cation{,} the salt PPhHOsHgHC(CO) crystallised from the reaction mixture. An X-ray single-crystal analysis of the latter has established its solid-state structure in which two OsC units are small micro-linked by a central mercury atom. The OsHgC(CO) cluster may be converted into the dimercury cluster dianion OsHgC(CO) by reaction with Hg(OSCF).