Synthesis of thiocarbonyl-bridged(η5-C5H5)2Fe2(CO)3(CS) and crystal structure of an s-alkylated derivative

Abstract The reaction of CpFe(CO) 2 − with (PhO) 2 CS, a new method of introducing a thiocarbonyl bridging ligand into a metal complex, yielded Cp 2 Fe 2 (CO) 3 (CS). The molecule exists as a cis-trans mixture in solution as evidenced by IR and NMR studies. On reaction with a variety of alkyl halides or other alkylating agents, stable S-alkyl derivatives are formed. The X-ray structure of [Cp 2 Fe 2 (CO) 3 (CSEt)]BF 4 is reported, and the nature of the bonding of the unusual CSEt + bridging group is discussed.