Synthesis, characterization and sorption properties of a porous coordination polymer: Co3(citrate)2(4,4′-bipyridine)4(H2O)2·4(H2O)

A porous coordination polymer, Co3(citrate)2(4,4′-bipyridine)4(H2O)2·4(H2O) has been synthesized and characterized. It adopts a 3-D framework, built up by parallel [Co3(citrate)2]n chains cross-linked by 4,4′-bipyridine ligands. The connection leads to hydrophilic cavities filled with water molecules, which interact with the citrate ligands through hydrogen bonds. Dangling 4,4′-bipyridine ligands are observed in the structure, pointing to cavities. Two equivalents of coordination water and four equivalents of crystallization water molecules can be removed reversibly based on TGA studies.