Electronic interaction between two fluorenyl-bridged molybdenocene dithiolene electroactive centers

Abstract

A bimetallic metal complex involving a fluorene linker between two redox active bis(cyclopentadienyl)molybdenum dithiolene moieties has been synthesized and characterized by electrochemistry and spectroelectrochemistry. Cyclic voltammetry experiments show sequential oxidation of the two redox centers with small ΔE values between the first and the second redox processes and between the third and the fourth ones. Comparative electrochemical studies carried out using either [NBu4][PF6] or the poorly coordinating supporting electrolyte [Na][B(C6H4(CF3)2)4] in dichloromethane indicate strong electrostatic effects on consecutive electron transfers, especially for highly charged species. Spectroelectrochemical investigations together with DFT calculations evidence that the two molybdenocene dithiolene electrophores are weakly electronically coupled through the organic bridge.