Hydrothermal Syntheses and Crystal Structures of Cobalt(II) Complexes Constructed by Dipyrido[3,2-a:2′,3′-c]phenazine and Different Carboxylate Ligands

Two new metal-organic complexes, {[Co(2)(bptc)(DPPZ)(2)(H(2)O)(2)]center dot H(2)O}(n) 1 and {[Co(2)(ccm)(2)(DPPZ)(2)]center dot 2H(2)O}(n) 2, were obtained by the hydrothermal reactions of Co(NO(3))(2)center dot 6H(2)O with chelating ligand dipyrido[3,2-a:2',3'-c]phenazine (DPPZ) and the corresponding carboxylic acid, namely, 3,3',4,4'-benzophenonetetracarboxylic acid (H(4)bptc) or 2-carboxycinnamic acid (H(2)ccm), respectively. The complexes were structurally characterized by single-crystal X-ray diffraction, elemental analyses, IR spectra, and thermal gravimetry. 1 presents unique chiral chain structures, which are further consolidated into three-dimensional supramolecular frameworks via noncovalent bonds, such as hydrogen bonding and pi-pi interactions. 2 features infinite double-chain structures, which are connected by strong pi-pi interactions to result in three-dimensional supramolecular architectures.