A damped non-linear least-squares computer program (DALSFRK) for the evaluation of reaction rate constants

Abstract

After consideration of the limitations of linear treatments for the analysis of kinetic data, a damped non-linear least-squares computer program (DALSFRK) is described. The program, which employs Marquardt's algorithm as the basis of minimisation, has been developed with the aid of synthetic data. The program is applied to an analysis of the kinetics of the halide-substitution reactions of [Pt(3NH-pd)X]⁺[X = halide, 3NH-pd = 3-azapentane-1,5- diamine (diethylenetriamine)]. It is shown that the present non-linear data treatment not only provides a very satisfactory overall analysis of the data but also enables an accurate evaluation of the first-order rate constants for the process (i). Such values have not previously been attainable directly by linear treatments. [Pt(3NH-pd)X]⁺ [graphic omitted] [Pt(3NH-pd)(OH₂)]²⁺+ X–(i)