Journal Title
Title of Journal: Transition Met Chem
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Abbravation: Transition Metal Chemistry
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Publisher
Springer Netherlands
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Authors: Puttaswamy J P Shubha R V Jagadeesh
Publish Date: 2007/08/03
Volume: 32, Issue: 7, Pages: 991-999
Abstract
pAminoazobenzene PAAB is one of the important monoazo dyes and its oxidation kinetic study is of much use in understanding the mechanistic profile of PAAB in redox reactions Consequently the kinetics of oxidation of PAAB by sodium Nchlorobenzenesulfonamide or chloramineB CAB in HClO4 medium and in NaOH medium catalyzed by rutheniumIII chloride RuIII have been investigated at 298 K Uv–vis spectrophotometry was used as a basic analytical approach in this study Under an identical set of experimental conditions the reactions of PAAB–CAB in HClO4 medium were facile but the reactions became too slow to be studied in alkaline medium and hence rutheniumIII chloride has been used as a catalyst in alkaline medium The stoichiometry 12 and oxidation products nitrosobenzene and pnitrosoaniline are the same in both media but the kinetic and mechanistic patterns were found to be different The experimental rate laws obtained are − dCAB/dt = k CAB0 PAAB0 H+ in acid medium and − dCAB0/dt = k CAB0 PAAB0OH− x RuIII y in alkaline medium where x and y are less than unity The reaction was examined with reference to changes in a concentration of benzenesulfonamide b concentration of added neutral salts c ionic strength d dielectric permitivity and e solvent isotope effect The reaction was also studied at different temperatures and the overall activation parameters have been evaluated The oxidation reaction fails to induce the polymerization of added acrylonitrile C6H4SO2NHCl and C6H4SO2NCl− have been postulated as the reactive oxidizing species in acidic and alkaline media respectively It was found that the reactions are nearly 20 times faster in acid medium in comparison with alkaline medium It was also observed that rutheniumIII was an efficient catalyst for the facile oxidation of PAAB by CAB in alkaline medium by making the reaction go twelvefold faster than the uncatalyzed reactions The catalytic constant K C has been calculated at different temperatures and the values of activation parameters with respect to rutheniumIII have also been evaluated in alkaline medium The observed results have been explained by plausible mechanisms and the relative rate laws have been deduced
Keywords:
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- Synthesis and X-ray crystal structures of a series of 3d–4f lanthanide complexes: lanthanide(III)–copper(II) coordination polymers with 2,5-pyridinedicarboxylic acid ligand
- Intermediates in reactions of the diimine complex trisferrozineiron(II) with hydroxide or cyanide in binary aqueous solvent mixtures and in micelles
- A novel series of nickel(II)-dppe-arylazoimidazole complexes. Synthesis and spectroscopic characterization
- Gold(I)-Gold(III)-4,4′-bpy-phosphine complexes: Synthesis and multinuclear NMR study
- A copper(II) complex of the Schiff base from l -valine and 2-hydroxy-1-naphthalidene plus 1,10-phenanthroline: synthesis, crystal structure, and DNA interaction
- Biophysical, spectroscopic and biochemical investigation of DNA–Cu(II)-GSH interactions
- Kinetics and mechanism of substitution of iron(II)–triazine complexes by 1,10-phenanthroline
- Three coordination polymers constructed from bis(imidazol-l-yl-methyl)benzene: syntheses, structures, and third-order nonlinear optical properties
- Synthesis and photophysical characterization of ruthenium(II) and platinum(II) complexes with bis-pyridylethynyl-phenanthroline ligands as a metalloligand
- DNA binding and photocleavage properties of two mixed-ligand oxovanadium complexes
- Infrared and Raman spectroscopic characterization of the phosphate mineral kosnarite KZr 2 (PO 4 ) 3 in comparison with other pegmatitic phosphates
- Outer-Sphere electron-transfer and the effect of linkage isomerism in the titanium(III) reduction of nitro-pentacyanocobaltate(III) and nitro-, and nitrito-pentaamminecobalt(III) complexes in aqueous acidic media
- A series of trinuclear sandwich-like cyanide-bridged iron(III)-manganese(II) complexes: synthesis, crystal structures, and magnetic properties
- Synthesis and physico-chemical studies on transition metal complexes of symmetric bis -Schiff base ligands
- Exchange coupling in di-μ-hydroxo-bridged chromium(III) dimers
- Inner sphere oxidation of N , N ′-ethylenebis(isonitrosoacetyleacetoneimine)copper(II) by N -bromosuccinimide in aqueous weakly acidic solutions
- Initial state and transition state solvation in substitution at the square-planar complexes, [PtCl 4 ] 2− and [Pd(Et 4 dien)Cl] +
- Detection of single nucleotide polymorphisms by the specific interaction between transition metal ions and mismatched base pairs in duplex DNA
- Catalysis of the coupling reaction of aryl chlorides with bis(pinacolato)diboron by tricyclohexylphosphine-cyclopalladated ferrocenylimine complexes
- An oxovanadium(IV) complex of an l -serine Schiff base and 1,10-phenanthroline: synthesis, crystal structure, and DNA and albumin-binding properties
- Mössbauer study of some iron(III) complexes with urea type ligands and the crystal structure of hexakisdimethylureairon(III) perchlorate
- Preparation and characterization of Co(II), Ni(II) and Cu(II) complexes of a ligand containing 1,3,4-thiadiazole groups
- Syntheses, crystal structures, and magnetic and fluorescence properties of three complexes of mixed flexible N,N′-bis(3-pyridylmethyl)amine and rigid pyromellitate ligands
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