Expedient Synthesis of a Metallostibine Os 2 (CO) 8 (µ‐SbPh): An Unusual and Strong Two‐Electron‐Donor Ligand

A metallostibine, Os 2 (CO) 8 (µ‐SbPh) ( 2 ), was generated readily and in high yield and purity from the Os 3 (CO) 11 (µ‐SbPh)(Cl) 2 ( 1 ) cluster through elimination of the terminal Os(CO) 3 (Cl) 2 Lewis acid fragment with activated γ‐alumina. Compound 2 is air sensitive in solution but relatively stable as a solid. The Sb atom in 2 adopts a trigonal pyramidal geometry in both the solid and solution states, with an active lone pair of electrons. Experimental and computational studies show that 2 is a strong two‐electron donor with a donor strength comparable to that of alkylphosphines.