Trichloridothallium(iii) complexes with bipyridine derivatives: From structure to luminescence properties

چکیده مقاله

Several new thallium(iii) complexes, [Tl(4,4′-dmbpy)Cl3(DMSO)] ·H₂O (1), [Tl(4,4′-dtbpy)Cl3(DMSO)] (2), [Tl(5,5′-dmbpy)Cl3(DMSO)]·(5,5′-dmbpy) (3), and [Tl(6-mbpy)Cl3(DMSO)] (4) (4,4′-dmbpy≤4,4′-dimethyl-2,2′- bipyridine, 4,4′-dtbpy≤4,4′-ditert-butyl-2,2′-bipyridine, 5,5′-dmbpy≤5,5′-dimethyl-2,2′-bipyridine, and 6-mbpy≤6-methyl-2,2′-bipyridine) were prepared from the reaction of TlCl3 with the mentioned ligands in DMSO. The four complexes were fully characterised and their structures were determined by X-ray diffraction. These complexes have a bidendate nitrogenous ligand, a DMSO molecule, and three chloride anions (in the facial position) attached to a TlIII metal centre in a distorted octahedral environment. The stability of the complexes in DMSO is evident by a 203,205Tl-1H spin-spin coupling, determined by 1H NMR spectroscopy. Interestingly, six bond hydrogen-thallium coupling was observed with a coupling constant of 6JTlH≤20Hz. The absorption and emission spectra of the complexes were investigated. These studies revealed that upon coordination to TlIII, the luminescent intensity is increased in comparison with the related unbound ligands. © 2013 CSIRO.