Reductive Trapping of [(OC)5W–W(CO)5]2− in a Mixed-Valent SmII/III Calix[4]pyrrolide Sandwich

Abstract

Reduction of tungsten hexacarbonyl by the divalent samarium(II) complex [Sm2(N4Et8)(thf)4] ((N4Et8)4−=meso-octaethylcalix[4]pyrrolide) in toluene at ambient temperature gave the remarkable heteronuclear mixed-valent samarium(II/III)/tungsten complex [{(thf)2SmII(N4Et8)SmIII(thf)}2{(μ-OC)2W2(CO)8}], which features the trapping of a rare [W2(CO)10]2− anion with an unsupported W−W bond.