New emissive fac-tricarbonylchlorobis(ligand)rhenium(I) complexes prepared from pyridine/thiophene hybrid ligands

Stille coupling between tributyl-(2,3-dihydro-thieno[3,4-b][1,4]dioxin-5-yl)-stannane and 4-bromopyridine resulted in the preparation of the new pyridine/thiophene hybrid ligand 4-(2,3-dihydro-thielio[3,4-b][1,4]dioxin-5-yl)-pyridine [4-py-EDOT] (1). Reaction of 1, 4-thiophen-2-yl-pyridine (2), or 4-[2,2']bithiophenyl-5-yl-pyridine (3) with ClRe(CO)(5) resulted in the isolation of complexes 4-6, ClRe(L)(2)(CO)(3), where L = 1, 2, or 3 respectively. The solid-state structure of 4 was determined by X-ray crystallography, which clearly shows the fac arrangement of the three CO ligands and the two 4-py-EDOT ligands arranged cis to one another. The metal complexes 4-6 have been characterized by H-1 and C-13 NMR, ESI or FAB MS, FTIR, UV-Vis, fluorescence, and elemental analysis. (C) 2004 Elsevier B.V. All rights reserved.