Chromium pentacarbonyl complexes of some dihydro- and tetrahydro-thiophene derivatives: determination of the type of bonding of chromium to a sulfoxide moiety

Chromium pentacarbonyl complexes of some dihydro- and tetrahydro-thiophenes and their sulfoxides have been prepared. In the sulfide derivatives the chromium is readily seen to be attached to the sulfur atom. The sulfoxide functionality also acts as a ligand for chromium, and by means of IR and mass spectra and the ESCA technique it was tentatively concluded that chromium is bonded to the sulfur atom of the sulfoxide. This assignment was confirmed by an X-ray analysis of 2,5-dihydrothiophene-1-oxide chromium pentacarbonyl.