title: Spectroscopic investigation on kinetics, thermodynamics and mechanism for electron transfer reaction of iron(III) complex with sulphur centered radical in stimulated biological system.
abstract: Electron transfer reactions of biological organic sulphides with several metal ions to generate sulphide radical cations are a great concern in biochemical process. To understand the mechanism, a stimulated biological system having model compounds, iron(III)-bipyridyl complex with thio-diglycolic acid (TDGA) was investigated. Spectroscopic study reveals the kinetics and thermodynamics of the reaction in aqueous perchloric acid medium. The reaction follows first and fractional order of 0.412 with respect to [Fe(bpy)3](3+) and TDGA, respectively. The oxidation is insensitive to variation in [H(+)] but slightly decreases with increase in ionic strength ([I]). Addition of acrylamide, a radical scavenger has no effect on the rate of the reaction. The high negative value of ΔS(#) (-74.3±1.09 J K(-1) mol(-1)) indicates the complex formed has a definite orientation higher than the reactants. Based on the above results, a suitable reaction mechanism for this reaction is proposed.
authors: Department of Chemical Engineering, Coimbatore Institute of Technology, Coimbatore 640 014, India.
authors: S
authors: S
authors: Deepalakshmi
authors: Department of Chemical Engineering, Coimbatore Institute of Technology, Coimbatore 640 014, India. Electronic address: sivalingam@cit.edu.in.
authors: A
authors: A
authors: Sivalingam
authors: Department of Chemical Engineering, Coimbatore Institute of Technology, Coimbatore 640 014, India.
authors: T
authors: T
authors: Kannadasan
authors: Research Department of Chemistry, Aditanar College of Arts and Science, Tirucendur 628 216, India.
authors: P
authors: P
authors: Subramaniam
authors: Department of Petroleum Engineering, JCT College of Engineering and Technology, Coimbatore 641 105, India.
authors: P
authors: P
authors: Sivakumar
authors: Department of Petrochemical Engineering, JCT College of Engineering and Technology, Coimbatore 641 105, India.
authors: S T
authors: ST
authors: Brahadeesh
mesh_terms: D015082:2,2'-Dipyridyl / Q000737:chemistry; D020106:Acrylamide / Q000737:chemistry; D004583:Electrons; D007501:Iron / Q000737:chemistry*; D007700:Kinetics; D009994:Osmolar Concentration; D012997:Solvents / Q000737:chemistry; D013057:Spectrum Analysis; D013455:Sulfur / Q000737:chemistry*; D013816:Thermodynamics; D013864:Thioglycolates / Q000737:chemistry
chemical_list: D012997:Solvents; D013864:Thioglycolates; D020106:Acrylamide; C010518:thiodiacetic acid; D015082:2,2'-Dipyridyl; D013455:Sulfur; D007501:Iron
keywords: Electron transfer reactions; Iron(III) complex; Kinetics; Mechanism; Thermodynamics