The synthesis, spectroscopic properties and electrochemistry of (8-quinolinolato)-bis-{1-alkyl-2- (arylazoimidazole)}ruthenium(ii) hexafluorophosphate: single crystal X-ray structure of [ru(q)(meaaime)2](PF6)·CH2Cl2 [Q = 8-quinolinolate, meaaime = 1-methyl-2-( p-tolylazoimidazole)

Abstract

The reaction of [Ru(OH2)2(RaaiR′)2]2+ [RaaiR′ = 1-alkyl-2-(arylazo)imidazole, p-R–C6H4–N=N–C3H2–NN(1)–R′, R=H (1), Me (2), Cl (3); R′ = Me (a), Et (b), CH2Ph (c)] with 8-quinolinol (HQ) in acetone solution followed by the addition of NH4PF6 afforded violet, mixed ligand complexes of composition [Ru(Q)(RaaiR′)2](PF6). The structure of [Ru(Q)(MeaaiMe)2](PF6) (2a) has been confirmed by X-ray diffraction studies. Solution electronic spectra exhibit a strong MLCT band at 560–580 nm in MeCN. Cyclic voltammogrames show a Ru(III)/Ru(II) couple at 1.0–1.1 V versus SCE along with three successive ligand reductions. The electronic properties are correlated with EHMO results.