Expedient Synthesis of a Metallostibine Os₂(CO)₈(µ‐SbPh): An Unusual and Strong Two‐Electron‐Donor Ligand

Abstract

A metallostibine, Os2(CO)8(µ‐SbPh) (2), was generated readily and in high yield and purity from the Os3(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.

The metallostibine Os2(CO)8(μ-SbPh): A versatile donor precursor for antimony-containing heterometallic clusters

“…Reagent grade solvents were dried over the appropriate drying agents and were freshly distilled prior to use. The clusters 1, Os3(CO)11(CH3CN), Os3(CO)10(CH3CN)2 and Ru3(CO)11(CH3CN), were prepared as described in the literatures [4,22]. TLC separations were carried out on 20 × 20 cm 2 plates coated with silica gel 60 Reaction of 2 with Fe 2 (CO) 9 .…”

“…We recently reported the synthesis of the metallostibine Os2(CO)8(-SbPh), 2, which exhibits strong donor strength comparable to that of alkylphosphines. It is also less sterically hindered compared to, for example, PPh3 [4]. It should thus be a versatile precursor for the introduction of both Sb and Os atoms, via simple substitution of a CO or other two-electron ligands, in the construction of larger clusters.…”