Synthesis, crystal structure, and photoluminescent properties of a tetracarbonyl(naphthyridylcarbamoyl)rhenium(I) complex and a highly emissive tetracarbonyl(naphthyridylamido)rhenium(I) complex

Abstract

The reactions of Re(CO)5X (X = Cl, Br) with 7-amino-2,4-dimethyl-1,8-naphthyridine (H2L1) and 7-[2-(6-chloropyridyl)-amino] -2,4-dimethyl-1,8 -naphthyridine (HL2) in the presence of tBuOK afforded the η1-naphthyridylcarbamoyl complex [Re(CO)4(HL1CO)] (1) and the naphthyridylamido complex [Re(CO)4(L2)] (2), respectively. The structures of HL2, 1·CHCl3, 1·HL3·2CH2Cl2 [HL3 = (7-chloronaphthyridyl)(5,7-dimethylnaphthyridyl)amine], and 2 have been determined by X-ray crystallography. Complex 1 displays a weak emission at 453 nm in an EtOH/MeOH (1:4, v/v) glassy solution at 77 K; complex 2 exhibits an intense (quantum yield: 0.22 in CH2Cl2) CH2Cl2) and long-lived emission (46 μs in CH2Cl2), with a solvent-sensitive λmax, in degassed solutions at room temperature. © Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2003).