Kinetics and Thermodynamics of Constitutional Dynamic Coordination Systems Based on FeII, CoII, NiII, CuII, and ZnII

The self-adaptation of constitutional dynamic systems based on selective coordination between 5,5-dimethyl-2,2-bipyridine and deuterium-labeled 4,4-dimethyl-2,2-bipyridine to Fe-II, Co-II, Ni-II, Cu-II, or Zn-II has been evaluated by ESI-MS in methanol. The equilibration rates of the systems proved dependent on the metal species, following the order Zn-II > Cu-II > Co-II > Ni-II > Fe-II, where Zn-II resulted in rapid rearrangement of the original homoleptic complexes. The heteroleptic complexes were favored in the systems with Co-II, Cu-II and Zn-II, whereas the homoleptic complexes were more pronounced with Fe-II and Ni-II.