Porous Supramolecular Networks Constructed of One-Dimensional Metal Organic Chains: Carbon Dioxide and Iodine Capture

In search of porous materials for selective sorption and iodine inclusion, we have found two networks made of chains with a kink at the metal nodes held together by supramolecular interactions (H-bond and pi pi stacking). The solvent can be removed and replaced reversibly without loss of crystallinity, as demonstrated by single-crystal-to-single-crystal crystallography. In contrast, iodine uptake degrades the crystallinity to amorphous, and it regains its crystalline state after removal of the iodine at 200 degrees C. Slight differences in behavior of the sorption and inclusion properties between the tetrahedral metal nodes, Zn and Co, are associated with the size of the nodes. An important feature is the extent of iodine that can be included between the chains that is doubled with temperature from 30 to 100 degrees C and exceeds the weight in mass of the compounds.