Sumon Ray

Kinetic Studies on Interaction of Platinum(II) Complexes with an ‘S’ Containing Ligand in Aqueous Medium

The kinetics of the substitution reactions of [Pt(dach)(H2O)2]2+ and [Pt(en)(H2O)2]2+ (where ‘dach’ and ‘en’ are cis-1,2-diaminocyclohexane and ethylenediamine, respectively) with excess N,N′-diethylthiourea have been studied in aqueous solution by UV–Vis spectrophotometry. The effect of different N–N spectator ligands on the reactivity of platinum(II) complexes was investigated by studying the water lability of the reactant complexes. The kinetic study has been substantiated by product isolation, IR, NMR and ESI-MS spectral analysis and DFT calculations. The reactions follow normal square-planar substitution mainly in an associative way. Rate parameters have been evaluated under different conditions. The substitution rates of the complexes studied can be tuned through the nature of the N–N chelates, which is important in the development of new active compounds for cancer therapy.

Kinetics and mechanism of reactions of some essential amino acids with cis-diaqua(1,3-diaminopropane)-platinum(II) ion: a potent anticancer agent

Abstract The substitution of both coordinated water molecules of cis-diaqua(1,3-diaminopropane)platinum(II) complex by a series of amino acids, viz. l-asparagine, l-glutamic acid, and glycine was investigated as a function of ligand concentration, temperature, and pH and found to occur in two consecutive reaction steps. The mechanism of the substitution reactions appears associative in nature as supported by the large and negative values of ΔS≠. The kinetic study has been substantiated by product isolation, UV, IR, and ESI-MS spectroscopic analysis and rate parameters have been evaluated under different reaction conditions.Graphical Abstract

Mechanistic and Kinetic Investigations on the Interaction of Model Platinum(II) Complex With Ligands of Biological Significance in Reference to the Antitumor Activity

The kinetics of interaction of cis-[Pt(cis-dach)(H2O)2]2+ (where dach is cis-1,2-diaminocyclohexane) with three different amino acids, namely L-Asparagine (L1H), L-Arginine (L2H), and L-Gluatmic acid (L3H) have been studied spectrophotometrically in the 40–60°C temperature range. The substitution was found to occur in two subsequent reaction steps: the first step is the ligand-assisted anation and the second one is the chelation step. The kinetic study has been substantiated by product isolation, IR, NMR, and ESI-MS spectroscopic analysis.

Kinetic studies on substitution of cis-diaqua-chloro-tris-(dimethyl sulphoxide)-ruthenium(II) complex with some dipeptides in aqueous medium

AbstractThe kinetics of interaction between cis-[RuCl(Me2SO)3(H2O)2] +  and some selected dipeptides such as glycyl glycine(gly gly), glycyl alanine(Gly-L-ala) and glycyl-L-leucine(gly leu) has been studied spectrophotometrically as a function of [RuCl(Me2SO)3(H2O)

Substitution reactions of [Pd(bipy)(malonate)] explored with a different set of ligands: Kinetic and mechanistic interpretation in aqueous medium and at pH 7.4

_{2}^{+}

Kinetic and mechanistic aspects of ligand substitution on cis -diaqua ( cis -1,2-diaminocyclohexane)platinum(II) with three glycine-containing dipeptides

], [dipeptide] and temperature at a particular pH(5.0), where the substrate complex exists predominantly as a diaqua species (in aqueous solution) and dipeptides as the zwitter ions. The reaction has been found to proceed via two distinct consecutive steps i.e., it shows a non-linear dependence on the concentration of dipeptide: first process is dependent and the second step is independent of ligand concentration respectively. The rate constants for the processes are: k

Mechanistic aspects of ligand substitution on cis -diaqua-chloro-tris(dimethyl sulfoxide) ruthenium(II) complex by adenosine and cytidine in aqueous medium

_{1} \sim 10^{-3}

Kinetic and Mechanistic Studies on the Interaction of Glycyl-L-alanine, Glycyl-L-asparagine, and Glycyl-L-tyrosine with Hydroxopentaaquarhodium(III) Ion

s − 1 and k

Displacement of aqua ligands from the hydroxopentaaquarhodium(III) ion by 1-hydroxybenzotriazole (HOBt): A kinetic and mechanistic approach

_{2} \sim 10^{-5}

Relative reactivity of N,N-donor ligands in substitution reactions of cis-diaqua(2-aminomethylpiperidine)platinum(II): a detailed kinetic and mechanistic study

s − 1. The activation parameters were calculated from Eyring plots suggests an associative mechanism for the interaction process. From the temperature dependence of the outer sphere association equilibrium constants, the thermodynamic parameters were also calculated, which gives a negative ΔG0 value at all temperatures studied, supporting the spontaneous formation of an outer sphere association complex. Graphical AbstractThe kinetics of interaction between cis-[RuCl(Me2SO)3(H2O)2]+ and some glycyl-containing dipeptides such as glycyl glycine(gly gly), glycyl alanine(gly ala) and glycyl-L-leucine(gly leu) has been studied spectrophotometrically as a function of [RuCl(Me2SO)3(H2O)2]+, [dipeptide] and temperature at a particular ph(5.0), where the substrate complex exists predominantly as a diaqua species (in aqueous solution) and dipeptides as the zwitter ions. The reaction has been found to proceed via two distinct consecutive steps: first process is [ligand] dependent whereas the second step is [ligand] independent. The rate constants for the processes are: k1~10−3s−1 and k2~10−5s−1.