Kinetics and mechanism of the reactions of platinum(II)‐dipicolinate and platinum(II)‐glycylglycine with oxalate ion

The kinetics of the reactions of [Pt(dipic)(H₂O)] and [Pt(digly)(H₂O)] (where H₂dipic = pyridine‐2,6‐dicarboxylic acid and H₂digly = glycylglycine) with oxalate ion were studied at 25°C in aqueous medium by UV–vis spectroscopy at I = 0.1 mol dm^?3 over an wide range of pH. A probable associative pathway may involve a five‐coordinate intermediate leading to the formation of an unidentate oxalate species, which converts to bidentate chelate in subsequent fast steps. The products are isolated and characterized by CHN analysis, IR, and ¹H NMR spectra. The kinetic data from pH variation experiments are fitted by a computer program to a sequence of reactions and the different rate constants are evaluated. © 2003 Wiley Periodicals, Inc. Int J Chem Kinet 35: 327–333, 2003     

Effect of temperature on adsorption and corrosion inhibition characteristics of gelatin on mild steel in hydrochloric acid medium

Research on Chemical Intermediates - Adsorption characteristics of a water-soluble bio-polymer, gelatin, on mild steel in 1-M hydrochloric acid (HCl) together with its potential corrosion resistive...     

Mixed ligand palladium(II) complexes of oxalate and malonate with vitamin-B6 molecules: synthesis,crystal structure and kinetics

The synthesis of six mononuclear palladium complexes of general formula [Pd(ox)/(mal)L₂] and [Pd(ox)/(mal)L] (ox = oxalate, mal = malonate, both L and L are vitamin-B₆ molecules (I), L = pyridoxine, pyridoxal and L = pyridoxamine) has been achieved. The structures of these compounds were established by elemental analysis, i.r. and ¹³C-n.m.r. [Pd(oxalate)(pyridoxine)₂] was analyzed by single crystal X-ray diffraction. It exhibits square planar coordination with bond lengths 2.015 (2) Å for Pd—N and 2.010 (2) Å for Pd—O. The interaction of [Pd(ox)₂]^2– and [Pd(mal)₂]^2– with L has been followed kinetically in order to look into the nature of products and the mechanism of formation under the conditions [Pd^II-chelate] [L] and [L].     

Reactions of platinum(II) dipicolinate complex with amino acids—chelation and isomerization

The kinetic course of the reactions of [Pt(dipic_tr)Cl]^? (where H₂dipic = pyridine‐2,6‐dicarboxylic acid; bonded in tridentate mode) with glycine, β‐alanine, and L‐histidine was followed at 25°C in aqueous medium at pH 3.00–10.73 at I = 0.5 mol dm^?3 (LiClO₄) spectrophotometrically and through ¹H NMR spectral analysis. The selectivity of platinum(II) toward the amino acids with regard to chelation and isomerization is controlled by donor atoms and steric properties. The aquation equilibrium of the designated platinum(II) complex also affects the binding rate in the case of glycine and β‐alanine. The reaction products have been isolated and characterized through ¹H NMR spectra. © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 34: 262–270, 2002