Synthesis and characterization of tetrairon–tungsten cluster complex containing a μ4, η2-carbonyl ligand

Abstract

Reaction of [(PPh 2C 5H 4)Cp 3Fe 4(CO) 4] ( 1) with (CO) 4W(CH 3CN) 2 at ambient temperature affords [(CO) 4W(PPh 2C 5H 4)Cp 3Fe 4(CO) 4] ( 2) as the major product, together with a small amount of [(CO) 5W(PPh 2C 5H 4)Cp 3Fe 4(CO) 4] ( 3). Compound 3 can be obtained in good yield by treating (CO) 5W(CH 3CN) with equal molar of 1, and reaction of 3 with Me 3NO in acetonitrile solvent produces 2 exclusively. The crystal structures of 2 and 3 have been determined by an X-ray diffraction study. Compound 2 contains an interesting μ 4, η 2-CO ligand, where two electrons donated by the carbon atom are involved to bridge a Fe 3 face and two electrons from oxygen are donated to the tungsten(0) atom.