An unusual 3D metal-organic framework with multiform helical chains

A new metal-organic framework, namely, {[Co2(oba)2(bib)]·H2O}n (1) (H2oba = 4,4′-oxybis(benzoic acid) and bib = 1,4-bis(2-methyl-imidazol-1-yl)butane), was prepared via self-assembly of the bib with cobalt salt in the presence of V-shaped oba ligand under mild condition. The structure of polymer 1 presents a six-connected self-interpenetrating 44.610.8 topological network with interweaving helical chains. In addition, the most stable conformation of bib has been analyzed by B3LYP calculation.