Kinetics and mechanism of substitution on square-planar palladium(II) complexes in mixed aqueous solvents

摘要: The kinetics of halide replacement in the complexes[Pd(iea)X]X and [Pd(ieda)X]X [iea = iminobis(ethyleneamine) ieda iminobis(ethylenediethylamine); X Cl- or l-] have been measured a variety mixed aqueous organic solvents. rate expression is Rate =k1+K2[X–]. Plots log k1 k2 against Grunwald–Winstein Y values are linear with gradients between 0.33 0.63. results interpreted terms similar associative mechanism for each reaction, involving appreciable Pd–X bond cleavage rate-determining transition state. utility k plots other free-energy relations (such as rate–equilibrium correlations) elucidating intimate mechanisms square-planar substitutions discussed.