Ak. Ghosh et Gs. De, MECHANISTIC STUDIES ON LIGAND SUBSTITUTION IN HEXAAQUARHODIUM(II) IONBY SALICYLALDOXIME, Indian journal of chemistry. Sect. A: Inorganic, physical, theoretical & analytical, 33(10), 1994, pp. 929-931
The kinetics of formation of [Rh(OH2)(4)(salH)](2+) from [Rh(OH2)(6)](
3+) has been studied spectrophotometrically by following the appearanc
e of a characteristic peak of the product complex (lambda(max) = 345 n
m) as a function of substrate and ligand concentrations, temperature a
nd solvent polarity. The rate of the reaction is found to be first ord
er each in [substrate] and [ligand]. Activation parameters (Delta H do
uble dagger = 54.4 kJ mol(-1), Delta S not equivalent to = - 77.0 JK(-
1) mol(-1)), compared with that of the water-exchange, suggest an asso
ciative mode of activation. Solvent effect study also helps to lead to
the same mechanistic conclusion.