Abstract

The synthesis, characterization and spectroscopic and theoretical studies of new kappa(1)-S monometallic Re-spy (1)/Re-thiopy (2) and kappa(1)-N-bimetallic Re-2-dps (3)/Re-2-dpds (4) complexes substituted with 4-mercaptopyridine derivatives are reported. The obtainment of either monosulfide bridge-complex (3) or disulfide bridge-complex (4) depends on the reaction media. The structure of complex3was confirmed by monocrystal X-ray diffraction. Additionally it was possible to determine the presence of an intramolecular interconversion between1and2mediated by solvent molecules through the intermediate species1-H(+)using UV-Vis and NMR spectroscopy. Electronic spectra calculated by TD-DFT feature distinct MLCT transitions for2and show that the pi-stacking interaction present in1is broken in the methanol/water mixture, leading to a structural distribution similar to2. Cyclic voltammograms of all complexes display the characteristic reduction process for the rhenium center and the bipyridine ligand. Additionally, an irreversible process associated with the bridging ligand for3and4is observed.