Synthesis and properties of new π-conjugated pyridine ligands with tetrathiafulvalene derivatives and the rhenium(I) tricarbonyl complexes

Three new π-conjugated pyridine ligands with redox-active tetrathiafulvalene (TTF) derivatives, L1–L3, have been synthesized and characterized. The Diels–Alder reaction is the key step for this multistep synthetic strategy. The crystal structures of L1 and L3 have been studied. The electrochemical and spectroscopic properties of these new ligands, as well as the corresponding tricarbonyl rhenium(I) complexes (ReL1(CO)3X, X = Cl, 5; X = Br, 6) have also been investigated.