Synthesis and characterisation of ruthenium polypyridyl complexes containing a pendent hydroquinone grouping

The synthesis of the ligand 1,4-dihydroxy-2,5-bis(3-(pyridin-2-yl)-1,2,4-tr iazol-1-yl)benzene (L1) and its mono and dinuclear rutheniumbis(2,2'-bipyri dyl) complexes are reported. The compounds obtained are characterised by NM R, UV-Vis and emission spectroscopy and have also been studied by electroch emical and spectroelectrochemical techniques. The data obtained suggest tha t L1 is bound to the metal centre via the pyridine ring and the N4 atom of the triazole moiety. The compounds emit at room temperature and electrochem ical studies show that the central hydroquinone unit is oxidised before the ruthenium centres. (C) 2000 Elsevier Science S.A.. All rights reserved.