A Bimetallic Benzene‐1,2,4,5‐Tetrathiolate (btt) Molybdenocene Complex Cp2Mo(btt)MoCp2: Radical and Diradical States

Abstract

AbstractBenzene‐1,2,4,5‐tetrathiolate (btt) has been used as a bridging ligand to prepare a redox active (molybdenocene dithiolene)‐based bimetallic complex Cp2Mo(btt)MoCp2, which exhibits four successive electron transfers up to the tetracation. Spectro‐electrochemical investigations together with DFT and TD‐DFT calculations evidence that the two electroactive MoS2C2 metallacycles are electronically coupled in the monocationic as in the dicationic state. Two salts of the dication [Cp2Mo(btt)MoCp2]2+ have been structurally characterized with PF6− and HSO4− counterions, showing different chair or boat conformations associated with variable folding angles of the two MoS2C2 metallacycles along the S−S hinge. The bis‐oxidized dicationic complex exhibits a diradical character, with both radicals essentially localized on the metallacycles and with antiferromagnetic coupling evidenced from magnetic susceptibility measurements.