Supramolecular Templating Approach for the Solvent-Free Synthesis of Open-Framework Metal Oxalates.

A series of open-framework metal oxalates (metal = Zn, Co, Mn, Bi, In) were prepared under solvent-free conditions by a supramolecular templating approach. These compounds have cationic, anionic, and neutral frameworks with pore apertures ranging from small 8-membered rings (8 MRs) to extra-large 16 and 20 MRs. The zinc oxalate exhibits a proton conductivity of 2.6 × 10(-3) S cm(-1) at 60 °C under 98% relative humidity.