Two 1-D zinc(II) coordination polymers based on flexible bis (2-methylbenzimidazole) and rigid dicarboxylate co-ligands

Two coordination polymers, {[Zn(bbi)(pydca)]center dot 2H(2)O}(n) (1) and [Zn(bmb)(1,3-bdc)](n) (2), where (bbi = 1,1'-(1,4-butanediyl) bis(2-methylbenzimidazole), H(2)pydca = pyridine-2,6-dicarboxylic acid, bmb = 1,3-bis(2-methylbenzimidazol-1-ylmethyl)benzene and 1,3-H(2)bdc = 1,3-benzenedicarboxylic acid), have been hydrothermally synthesized and characterized by elemental analysis, IR spectroscopy, and powder and single-crystal X-ray diffraction. Structural analysis showed that 1 is a 1-D zigzag chain coordination polymer, which is further linked into a 3-D supramolecular framework via classical O-H center dot center dot center dot O hydrogen bonding interactions. In 2, the 1-D loop-like chains are additionally assembled by four C-H center dot center dot center dot pi hydrogen bond interactions to construct a 3-D supramolecular network. The thermal stabilities and fluorescence properties of the complexes were investigated.