Abstract
We report herein syntheses of medium-nuclearity very-mixed metal clusters by an unusual combination of core expansion and metal exchange upon reacting MIr3(CO)11(è-L) (M ) Mo, W; L ) C5H5,C5HMe4,C5Me5) with [M(CO)3(è-L)]- (M ) Mo, W; L ) C5HMe4,C5Me5), the metal exchange being a remarkable “ligand-driven” process, together with comprehensive theoretical, structural, and spectroscopic studies of the resultant species, and studies clarifying aspects of the reaction mechanism.