TUNING OF THE PHOTOSTABILITY OF BIS(2,2'-BIQUINOLINE)RUTHENIUM(II) COMPLEXES CONTAINING PYRIDYLTRIAZOLE LIGANDS BY VARIATION OF PH

摘要

The synthesis and characterisation of [Ru(biq)(2)(LL')](n+) compounds, where LL' = 3-methyl-5(pyridin-2-yl)-1,2,4-triazolate (3Meptr(-), n = 1) and 1-methyl-3(pyridin-2-yl)-1,2,4-triazole (1Meptr,n = 2) and biq = 2,2'-biquinoline are reported. NMR spectroscopy has been used to elucidate the coordination mode of the ligands. The complexes have been further characterised by electrochemical, UV-Vis absorption and emission measurements. The acid-base behaviour of [Ru(biq)(2)(3Meptr)](+) has been studied and a pK(a) of 4.1 +/- 0.2 is obtained for the coordinated triazole ligand. The photochemical properties of the H3Meptr complex can be tuned by varying the pH. When the triazole ligand is deprotonated the big complex is photostable, but upon protonation of the triazole ring, photolabilisation of the LL' ligands is observed. [References: 46]