Syntheses, structures, and properties of tricarbonyl rhenium(I) heteronuclear complexes with a new bridging ligand containing coupled bis(2-pyridyl) and 1,2-dithiolene units

A new type of polypyridine ligand containing coupled bis(2-pyridyl) and cyanoethylthio-protected dithiolene, 4,5-bis(2-cyanoethylthio)-2-bis(2-pyridyl)methylene-1,3-dithiole (BPyDT(SCH2CH2CN)(2), 3), two mononuclear complexes, BrRe(CO)(3)(BPyDT(SCH2CH2CN)(2)) (4) and BPyDTS2Pt(dbbpy) (7), and one homodinuclear complex, BPyDT(SAuPPh3)(2) (5), have been synthesized and characterized. With the deprotected polypyridine ligand BPyDTS22- as the bridging unit, one tricarbonyl rhenium(l) heterotrinuclear complex, ClRe(CO)(3)(BPyDT(SAuPPh3)(2)) (6), and one heterodinuclear complex, ClRe(CO)(3)(BPyDTS2Pt(dbbpy)) (8, dbbpy = 4,4'-di-tert-butyl-2,2'-bipyridine), have been studied. The structures of all these compounds have been determined by X-ray crystallography. UV-vis studies have been carried out for them, showing distinct electronic absorptions. Compounds 3-6 exhibit blue to red luminescence in CH(2)l(2) solution at room temperature. Ground-state electronic structures for 3-8 have been analyzed by the B3LYP calculations.