title: New types of the flexible self-assembled metal-organic coordination polymers constructed by aliphatic dicarboxylates and rigid bidentate nitrogen ligands.
abstract: The reaction of metal ions, flexible aliphatic dicarboxylates and rigid bidentate linear ligands under mild conditions in water afford four novel metal-organic coordination polymers, [Cd(mu-mal)(mu-pyz)(0.5)(H(2)O)](n) 1 (mal = malonate dianion, pyz = pyrazine), [Cd(2)(mu-suc)(2)(mu-pyz)(H(2)O)(2)](n) 2 (suc = succinate dianion), and ([M(mu-bipy)(H(2)O)4][suc].4H(2)O)(n)(M = Co, 3, M = Zn, 4, bipy = 4,4'-bipyridine). The molecular structures of 1-4 have been established by single-crystal X-ray crystallography. 1 is a 3D network being composed of layers of octahedrally coordinated Cd atoms bridged by malonate anions in syn-anti configurations within the layers and pyz molecules between layers. Unlike that in 1, each Cd atom in 2 displays uncommon pentagonal-bipyramidal geometry to form 2D infinite grid sheets with square grid dimensions of ca. 7.936 x 7.936 [Angstrom]. Both 3 and 4 exhibit 1D linear -M-bipy-M-bipy- chain polymers, and these chains were packed as ...ABCABC... layered structures. The bridging succinate ligands in 2 adopt the syn-anti mode with a torsion angle of 60.8(7) degrees, while the solvated succinate ligands in 3 and 4 adopt the anti-anti mode with a torsion angle of 180.0 degrees. To our knowledge, compound 2 represents the first example of flexible self-assembled succinate-pyrazine mixed bridging ligand coordination network. 3 and 4 are the first two cases of succinate-bipy polymers with non-coordinated succinate. The magnetic behavior for 3 was studied in the temperature range of 5-300 K. The result indicates the occurrence of a weak antiferromagnetic coupling between the cobalt(II) ions.
authors.affiliation: Departmrnt of Chemistry, Northeast Normal University, Changchun 130-024, P.R. China.
authors.forename: Hongyan
authors.initials: H
authors.lastname: Mao
authors.forename: Changzheng
authors.initials: C
authors.lastname: Zhang
authors.forename: Gang
authors.initials: G
authors.lastname: Li
authors.forename: Hongyun
authors.initials: H
authors.lastname: Zhang
authors.forename: Hongwei
authors.initials: H
authors.lastname: Hou
authors.forename: Linke
authors.initials: L
authors.lastname: Li
authors.forename: Qingan
authors.initials: Q
authors.lastname: Wu
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhu
authors.forename: Enbo
authors.initials: E
authors.lastname: Wang