Coordination-directed self-assembly of M12L24 nanocage: effects of kinetic trapping on the assembly process.

We demonstrate the spontaneous formation of spherical complex M12L24, which is composed of 12 palladium ions and 24 bidentate ligands, by molecular dynamics simulations. In contrast to our previous study on the smaller M6L8 cage, we found that the larger M12L24 self-assembly process involves noticeable kinetic trapping at lower nuclearity complexes, e.g., M6L12, M8L16, and M9L18. We also found that the kinetic trapping behaviors sensitively depend on the bend angle of ligands and the metal-ligand binding strength. Our results show that these kinetic effects, that have generally been neglected, are important factor in self-assembly structure determination of larger complexes as M12L24 in this study.