Basic building units, self-assembly and crystallization in the formation of complex inorganic open architectures

Careful investigations of open-framework metal phosphates reveal that the formation of these complex architectures is likely to involve a process wherein one-dimensional ladders or chains, and possibly zero-dimensional monomers, transform to higher dimensional structures. The one-dimensional ladder appears to be the primary building unit of these structures. At one stage of the building-up process, spontaneous self-assembly of a low-dimensional structure such as the ladder seems to occur, followed by crystallization of a two- or three-dimensional structure. Accordingly, many of the higher dimensional structures retain the structural features of the 1D structure, indicating the occurrence of self-assembly. These findings mark the beginnings of our understanding of complex supramolecular inorganic materials.