Structural diversity in metal-organic nanoscale supramolecular architectures

Supramolecular synthesis has gained much attention in recent years. Such an approach to synthesis represents an attractive alternative to traditional, multi-step synthesis, especially for making complex, nanoscopic structures. Of particular interest, in the context of this work, is the use of metal-organic interactions to direct the self-assembly of nanoscopic architectures. These interactions are highly directional, relatively "strong" (compared to other supramolecular interactions) and kinetically labile, which allows for "self-correction" and in turn the production, often in high yield, of defect-free products. This also means that a number of related, yet structurally diverse products (supramolecular isomers) could be isolated.; The work presented herein demonstrates the supramolecular synthesis of related, yet structurally diverse family of metal-organic nanoscale supramolecular architectures that are based on the ubiquitous paddle-wheel dimetal tetracarboxylate secondary building unit (SBU) and angular dicarboxylate ligands. It also demonstrates that the SBU self-assembles into clusters of four (tetragonal) and three (trigonal) nanoscale secondary building units (nSBU), which further self-assemble into nanoscale structures that include discrete (OD) faceted polyhedra, tetragonal 2D sheets and another 2D sheet that conforms to the so-called Kagome lattice. In addition, the work herein demonstrates that synthesis under thermodynamic equilibrium conditions facilitates "self-correction" so that the most stable thermodynamic product is obtained. Synthesis, characterization and crystal structure analysis of these structures is presented herein.