Kinetics and mechanism of substitution of aqua ligands from cis-diaqua- bis(bipyridyl ruthenium(II)) complex by salicylhydroxamic acid in aqueous medium.

Autor: Mahanti, Bibekananda, Sankar, Gouri
Zdroj: Transition Metal Chemistry; Dec1992, Vol. 17 Issue 6, p521-524, 4p
Abstrakt: The kinetics of substitution of aqua ligands from cis-[Ru(bipy)(HO)] ion by salicylhydroxamic acid (L) in aqueous medium has been studied spectrophotometrically at different temperatures (50-65°C). The following rate law has been established in the pH range 4.0 to 5.8; where k is the water dissociation rate constant of the reactant complex, k is the aquation rate constant, k is the ligand (in neutral form i.e., SHAH) capturing rate constant and k′ is the ligand (in anionic form i.e. SHA) capturing rate constant of the penta coordinated intermediate, [Ru(bipy)(HO)]. Activation parameters have been calculated and compared with other substitution reactions of this complex. The rate increases with the increase in pH. The k values decrease with the decrease of the dielectric constant of the medium. The experimental results are consistent with a dissociative mechanism. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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