ReI(CO)3+ complexes with N∧O- bidentate ligands

Simple reactions between Re(CO)(5)Cl and 2-benzoxazol-2-ylphenol, 2-benzothiazol-2-ylphenol or 2-(1-methyl-1H-benzoimidazol-2-yl)phenol (performed in boiling toluene) lead to dimeric complexes of general formula Re-2(CO)(6)(Nboolean ANDO(-))(2). The obtained dimeric species are quite stable in non-coordinating solvents, but in coordinating media (e. g., pyridine-pyr) they undergo disscociative solvolysis to form monomeric derivatives of general formula Re(CO)(3)(Nboolean ANDO(-))pyr. Molecular structures of both the dimeric and monomeric forms have been confirmed by means of X-ray measurements, electron impact mass spectrometry and IR spectroscopic investigations. UV-VIS absorption and emission properties of the newly synthesized Re(CO)(3)(+) complexes have been investigated and briefly compared with those previously reported for their 8-oxyquinolinato analogues.