ABSTRACT
Amphiphilic ruthenium(II) complexes IIIV were synthesized and their photophysical properties were investigated in the presence of anionic (SDS), cationic (CTAB) and neutral (Triton X-100) micelles. The absorption and emission spectral data in the presence of micelles show that these Ru(II) complexes are incorporated in the micelles. There are two types of interaction between complexes IIV and the micelles: hydrophobic and electrostatic. In the case of cationic micelles (CTAB), the hydrophobic interactions are predominant over electrostatic repulsion for the binding of cationic complexes IIIV with CTAB. In the case of anionic micelles (SDS), electrostatic interactions seem to be important in the binding of IIIV to SDS. Hydrophobic interactions play a dominant role in the binding of IIIV to the neutral micelles, Triton X-100. Based on the steady state and luminescence experiments, the enhancement of luminescence intensity and lifetime in the presence of micelles is due to the protection of the complexes from exposure to water in this environment.
Subject(s)
Micelles , Ruthenium/chemistry , Anions/chemistry , Cations/chemistry , Coordination Complexes/chemical synthesis , Coordination Complexes/chemistry , Hydrophobic and Hydrophilic Interactions , Octoxynol/chemistry , Spectrometry, Fluorescence , Static ElectricityABSTRACT
Three ruthenium(II)-bipyridine complexes carrying a tyrosine moiety were synthesized and photophysical and electron transfer studies with quinones were carried out using absorption and emission spectral techniques. The binding efficiency of quinones with ruthenium(II)-bipyridine complexes was also studied using these techniques. The binding efficiency was moderate and similar for all complexes with all quinones. The quenching modes were also similar and efficient for all complexes with all quinones. The quenching processes were diffusion controlled. The rate of electron transfer was calculated using semiclassical theory.
Subject(s)
Organometallic Compounds/chemistry , Pyridines/chemistry , Quinones/chemistry , Ruthenium/chemistry , Tyrosine/chemistry , Electron Transport , Molecular Structure , Organometallic Compounds/chemical synthesisABSTRACT
[Ru(dcbpy)(3)](2+) (dcbpy = 4,4'-dicarboxyl-2,2'-bipyridine) ion, in the excited state, undergoes facile electron transfer (ET) reaction with aryl methyl and dialkyl sulfides and the quenching rate constant, k(q) value is sensitive to the structure of the sulfide. The detection of the sulfur radical cation in this system using time-resolved transient absorption spectroscopy confirms the ET nature of the reaction. The semiclassical theory of ET has been successfully applied to the photoluminescence quenching of [Ru(dcbpy)(3)](2+) with sulfides. This is the first report for the generation and detection of sulfide radical cations from the excited state reaction of Ru(II) complex with organic sulfides.
