The acid dissociation constants of some orthopalladated complexes have
been determined in 10% v/v DMSO/water mixed solvent. The positive cha
rge is located on the Pd(II) atom; in basic medium the H atom on the l
igand is partially released, which convert these complexes into zwitte
rions, The ionization constants of the two overlapping equilibria of t
he HA-dppm-AH complex were evaluated by application of the separation
method. (C) 1998 Elsevier Science B.V. All rights reserved.