Rhenium(I) Tricarbonyl Complexes with New Pyridine Ligands Containing Crown Ether-Annelated or Anthracene-Functionalized 1,3-Dithiole-2-ylidene

Two bispyridine ligands containing crown ether-annelated or anthryl-substituted 1,3-dithiole-2-ylidene, 4,5-dithia-(3′,6′,9′,12′-tetraoxatetradecyl)-2-bis(2-pyridyl)methylene-1,3-dithiole (BPyDT(O4S2), 3) and 4-methylthio-5-[{2-(9′-anthryloxy)-ethyl}thio]-2-bis(2-pyridyl)methylene-1,3-dithiole (BPyDT(SMe)(SEA), 7), have been synthesized and characterized. The rhenium(I) tricarbonyl complexes ClRe(CO)3(BPyDT(O4S2)) (4) and BrRe(CO)3(BPyDT(SMe)(SEA)) (8) have been prepared based on them. The crystal structures of compounds 3, 4, and 8 have been determined. Complexes 4 and 8 exhibit greenish-yellow emission, while ligands 3 and 7 show blue luminescence in fluid solutions at room temperature. Redox properties of 3, 4, 7, and 8 have been investigated by cyclic voltammetry, and the crown ether-annelated compounds 3 and 4 show significant Na+-binding properties with large positive redox shifts.