High molecular weight reversible coordination polymers

In supramol. polymers, monomeric units are connected by reversible, non-covalent interactions. Solid state coordination polymers are well-known but few reversible coordination polymers have been studied in soln. We are interested in reversible coordination polymers contg. transition metals with catalytic activity. For this purpose, we have investigated the complex of palladium dichloride and 1,12-bis(diphenylphosphino)dodecane. In this system, ring- and chain-structures are in equil. Our investigations have led to the prodn. of high mol. wt. polymer. This polymer is reversible and in dil. soln. establishes equil. with cyclic oligomers with a time const. of 13 h. In order to avoid equilibration, the analogous platinum complex was synthesized. This system indeed showed slower exchange kinetics. Combined 31P-NMR and SEC studies have been performed to study the role of Pt centers coordinated by 3 phosphine ligands in the formation of networks. [on SciFinder (R)]