Two polyhedral frameworks of an M12L24 spherical complex revealed by replica-exchange molecular dynamics simulations

Abstract

We performed replica-exchange molecular dynamics (REMD) simulations for self-assembly of an M12L24 spherical complex that consists of 12 palladium ions (M) and 24 bent ligands (L). We found two metal-ligand frameworks with polyhedral structure were mainly observed with almost equal probability. One of the two frameworks, which has the lowest potential energy, has the same symmetry, Td, as the framework determined by the X-ray crystallographic analysis. The other framework, which has a slightly higher probability, has a different symmetry, C3v. The latter framework is less likely to be observed experimentally than the former because of the difficulty in crystallization.