Publications (3)3.84 Total impact
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Article: Structural and photophysical characterisation of coordination and optical isomers of mononuclear ruthenium(II) polypyridyl 1,2,4-triazole complexes
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ABSTRACT: The X-ray crystal structure of the N2 isomers of the Ru(bipy)2 complexes of Hphpztr (1) and Hpztr (2), (bipy = 2,2'-bipyridine, Hphpztr = 2-(5'-phenyl-4'H-[1,2,4]triazol-3'-yl)pyrazine and Hpztr = 2-(4'H-[1,2,4]triazol-3'-yl)pyrazine) are reported. The molecular structure obtained for 2 demonstrates an interesting structural aspect in the sharing of a single proton between two molecular units. The isolation of the Δ and Λ stereoisomers of 1 and [Ru(phen)2(pztr)]+ (phen = 1,10-phenanthroline) (3) by semipreparative HPLC is also reported. The compounds obtained are characterised by electronic spectroscopy and particular attention is paid to the photophysical properties of Δ and Λ isomers of 1 and 3, in chiral enantiopure and racemic solvents.Dalton Transactions 01/2003; · 3.84 Impact Factor -
Article: Ruthenium(II) and osmium(II) polypyridyl complexes of an asymmetric pyrazinyl- and pyridinyl-containing 1,2,4-triazole based ligand. Connectivity and physical properties of mononuclear complexes
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ABSTRACT: The synthesis, purification and characterisation of two coordination isomers of ruthenium(II) and osmium (II) complexes containing the ligand 3-(pyrazin-2'-yl)-5-(pyridin-2"-yl)-1,2,4-triazole (Hppt) are described. The X-ray and molecular structure of the complex [Ru(bipy)2(ppt)]PF6·CH3OH is reported, where the Ru(bipy)2-centre is bound to the ppt- ligand via the pyridine nitrogen and the N1 atom of the triazole ring. 1H NMR spectroscopic measurements confirm that in the second isomer the Ru(bipy)2-moiety is bound via the N2 atom of the triazole ring and the pyrazine ring. Partially deuteriated metal complexes are utilised to facilitate interpretation of 1H NMR spectra. The redox and electronic properties indicate that there are significant differences in the electronic properties of the two coordination isomers obtained. The acid–base properties of the compounds are also reported and show that the pKa of the 1,2,4-triazole ring varies systematically depending on the nature of the non-coordinating substituent. Analysis of these data indicates a significant electronic interaction between the pyridyl/pyrazyl rings and the 1,2,4-triazole ring in the coordinated ppt- ligand. -
Article: A 2:1 Co-Crystal of Hydroquinone and 3,5-Bis(2-pyridyl)-1,2,4-triazole
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ABSTRACT: The title compound, 2C₁₂H₉N5₅.C₆H₆O₂, exhibits a three-dimensional hydrogen-bonded network of N-H...N, C-H...N, O-H...N, C-H...O, C-H...π and π...π interactions.Nieuwenhuyzen, M. and Keyes, Tia E. and Gallagher, John F. and Vos, Johannes G. (1997) A 2:1 Co-Crystal of Hydroquinone and 3,5-Bis(2-pyridyl)-1,2,4-triazole. Acta Crystallographica Section C, 53 (12). pp. 1873-1875. ISSN 0108-2701.
