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

Benzene‐1,2,4,5‐tetrathiolate (btt) has been used as a bridging ligand to prepare a redox active (molybdenocene dithiolene)‐based bimetallic complex Cp 2 Mo(btt)MoCp 2 , 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 MoS 2 C 2 metallacycles are electronically coupled in the monocationic as in the dicationic state. Two salts of the dication [Cp 2 Mo(btt)MoCp 2 ] 2+ have been structurally characterized with PF 6 − and HSO 4 − counterions, showing different chair or boat conformations associated with variable folding angles of the two MoS 2 C 2 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.