Bimetallic electroactive titanocene dithiolene complexes

Three tetrathiolate derivatives have been investigated as bridging ligands to prepare redox active (titanocene dithiolene)-based bimetallic complexes, namely 1,2,4,5-benzenetetrathiolate, 1,2,3,4-butadiene tetrathiolate and benzene-1,4-di(ethylenedithiolate). The corresponding bimetallic bis(cyclopentatienyl) Ti (IV) dithiolene complexes were synthesized and structurally characterized. Comparison of the electrochemical properties of these bimetallic complexes with those of the corresponding monometallic complex, highlights the instability of the reduced species Ti (III) which was so far unknown in the monometallic one. UV–vis-NIR spectroelectrochemical studies confirm a more rapid decomposition of the reduced species for the bimetallic complexes compared to the monometallic one, as already observed for the oxidized species. Bimetallic complexes involving titanocene-dithiolene moieties connected to conjugated organic linkers were synthesized, structurally characterized and analysed through electrochemical and spectroelectrochemical investigations. • Bimetallic redox active titanocene(dithiolene) complexes syntheses and structures. • Monitoring of the stability of the oxidized and reduced species by spectroelectrochemistry. • Demonstration of the instability of the reduced Ti(III) species.