Initial-state and transition-state contributions to solvent effects on reactivity for the reaction of cis-dichlorobis(4-cyanopyridine)platinum(II) with thiourea in binary aqueous solvent mixtures

Abstract

Rates, rate laws, and rate constants are reported for the reaction of the title complex cis-[Pt(4CN-py)₂Cl₂] with thiourea, thiocyanate, and iodide in 50%(v/v) methanol, at 298.2 K. From the measured rates of reaction of cis-[Pt(4CN-py)₂Cl₂] with urea and solubilities of these two compounds in a variety of binary aqueous solvent mixtures, the initial-state and transition-state contributions to the reactivity trends have been deduced. For this reaction initial-state effects are considerably more important than transition-state effects.