Document Type : Research Article
Department of Chemistry & Research Centre, Scott Christian College (Autonomous), Nagercoil, India
Quinones are considered as a class of organic compounds having a quinonoid group and are ultimate electron acceptors. Due to this property, they have favourable redox potential and have the ability to form stable hydrogen bonds. Luminescence quenching is one of the important techniques used to get numerous informations regarding the structure and dynamics of a luminophore. To comprehend the quinones' electron-accepting characteristics, a variety of transition metal complexes have been synthesized and researches were carried out. Of them, Ru(II) polypyridyl complexes have widespread applications in electron transfer reactions due to their well-defined photophysical and photochemical stability. The reaction of excited state Tris(4,4ˈ-dimethoxy-2,2ˈ-bipyridine) ruthenium(II)tetrafluoroborate [Ru(dMeObpy)3](BF4)2 complex with quinones were investigated through photoinduced electron transfer reaction in homogeneous and microheterogenous medium. Luminescence quenching technique has been used to study this reaction. The complex has an absorbance maximum of 448 nm in aqueous medium ..The quenching rate constants were deduced using Stern - Volmer equation. The interaction between the complex and the cationic micelle CTAB, were analyzed based on electrostatic interaction and the hydrophobicity. The plot between RTlnkq vs reduction potential of the quinones as well as the transient absorption spectra confirmed the oxidative nature of quenching of the ruthenium complex in presence of quinones.The quenching constant values are influenced by many factors such as the nature of the ligand, medium, size and structure of quenchers, electron transfer distance between the donor and the acceptor. The formation of Ru3+ species is confirmed by its characteristic absorption at 600 nm.