Kinetic studies on substitution of cis-diaqua-chloro-tris-(dimethyl sulphoxide)-ruthenium(II) complex with some dipeptides in aqueous medium
Arup Mandal Parnajyoti Karmakar Subhasis Mallick Biplab K Bera Subala Mondal Sumon Ray Alak K Ghosh
Click here to view fulltext PDF
Permanent link:
https://www.ias.ac.in/article/fulltext/jcsc/124/04/0801-0807
The 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)$^+_2$], [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 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$_1 \tilde 10^{−3}$s-1 and k$_2 \tilde 10^{−5}$ 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.
Arup Mandal1 Parnajyoti Karmakar1 Subhasis Mallick1 Biplab K Bera1 Subala Mondal1 Sumon Ray1 Alak K Ghosh1
Volume 135, 2023
All articles
Continuous Article Publishing mode
Click here for Editorial Note on CAP Mode
© 2022-2023 Indian Academy of Sciences, Bengaluru.