UC Santa Cruz

Molecules are architectures of atoms, while crystal engineering of crystalline solids deals with targeted structures built from molecules. As the prototype of polymeric crystal engineering, coordination polymers (CPs), in some cases also described as metal-organic frameworks (MOFs), are an intriguing class of hybrid materials, which exist as infinite crystalline lattices extended from inorganic vertices (metal ions or clusters) and organic ligand supports by coordination interactions. The last decade has seen enormous research efforts in the syntheses and studies of coordination polymers. However, the emphasis is placed on the investigations of structural properties and potential applications of cationic coordination polymers such as anion exchange, photoluminescence, and electrocatalysis. In particular, silver(I) coordination polymers have established much attention due to its flexible coordination sphere which affords diverse topologies and dimensionalities. Besides the versatility of silver coordination geometry, synthesis of organic ligands represents equally important factors in the assembly process. Because of the facile formation of Ag-N bonds, N-donor containing ligands have widely been studied. Ag-ligand interactions are labile, which allows the silver CPs to control structural modifications for guest removal or ion exchange properties. Another interesting factor is that the presence of ligands and metal ions linked in the crystal structure allows for various possible excitation/emission scenarios which also provide photoluminescence processes. Lastly, transitional metal coordination polymers can be controlled via synthesis by their pore size, crystallinity, and availability of various functional groups which made them attractive as electrochemical storage materials for fuel cells.