Orthogonal control of dissociation dynamics relative to thermodynamics in a main-chain reversible polymer.

A pair of homologous and soluble reversible polymers display nearly identical solution structures but dramatically different dissociation dynamics (1.0 vs ca. 100 s-1) along their main chains. The polymers are formed by organopalladium-pyridine coordination, and steric effects at the metal center control the dynamics. Importantly, the association constant is not significantly affected by the sterics. The resulting orthogonal control over dissociation kinetics provides a general tool for studying the effects of dynamics independent of thermodynamics in supramolecular systems, particularly main-chain reversible polymers.