KINETICS OF LIGAND REPLACEMENT, IN N-SUBSTITUTED ETHYLENEDIAMINE PALLADIUM(II) COMPLEXES

The rate of substitution by ethylenediamine, of Cl-, in the substrates [Pd(R2N(CH2)(2)NR2)Cl-2] and of 2.2'-bipyridine (bpy), in the complex es [Pd(bpy)(R2N(CH2)(2)NR2)](ClO4)(2) (R = H, methyl, ethyl or phenyl) have been studied, at 25 degrees C, respectively in dimethylformamide and in water. In both processes the rate of reaction depends on the n ature of the substituent R at nitrogen. While the kinetic data for neu tral complexes can be accounted for simply in terms of electronic and steric properties of the ligands, the trend of the kinetic constants s eem to be related to the capacity of the various complexes to form hyd rogen bonding with water. (C) 1997 Elsevier Science Ltd.