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Hydrothermal reaction of cyano-substituted viologen derivatives and NaN3 with corresponding metal salts in the presence/absence of H2PTA (H2PTA = p-phthalic acid) yielded three azide-based polynuclear coordination polymers: [Co4(N3)4(PTA)3(4-CV)2]n·2nH2O 3D (1), [Co4(N3)4(PTA)3(3-CV)2]n·nH2O 3D (2), and [Cu6(N3)14(4-CV)2]n 2D (3) (3/4-CV+ = 4,4'-bipyridinium-N-methyl-3/4-benzonitrile). The azido bridges are employed to construct two types of polynuclear cluster units: tetranuclear [Co4(μ1,1-N3)4] and hexanuclear [Cu6(μ1,1-N3)6(μ1,1,1-N3)4]. Polymers 1 and 2 are isostructural, and exhibit similar 3D frameworks constructed by unprecedented linear tetranuclear CoII 4 units with a four-connected 65·8 topology. Polymer 3 features a 2D (4,4) topological network built up by hexanuclear CuII 6 segments. The azide anion exhibits diverse coordination modes: μ1,1-N3 in 1 and 2, and μ1,1-, μ1,3-, μ1,1,1- and μ1,1,3-N3 in 3. Variable-temperature magnetic susceptibility data denote that 1 and 2 display a weak antiferromagnetic interaction in CoII 4 units and 3 shows a dominant ferromagnetic exchange in CuII 6 units. [ABSTRACT FROM AUTHOR]

Hydrothermal reaction of ZnCl2, NCCH2CH2COONa and NaN3, in the absence/presence of auxiliary ligand 2,2′-bipy/4,4′-bipy, gave birth to three novel coordination polymers, namely, [Zn(tzp)]n(1), [Zn2(tzp)(N3)(OH)(2,2′-bipy)]n(2) and [Zn2(tzp)2(4,4′-bipy)]n(3) (H2tzp = 1H-tetrazolate-5-propionic acid). The tzp2−ligand was in situgenerated through the [2 + 3] cycloaddition reaction of nitrile and azide, which was first untilized to synthesize coordination compounds. Polymer 1behaves as a three-dimensional (3-D) network built up by the fusion of one-dimensional (1-D) pseudo-channels formed by the linkage of tzp2−ligands and tetrahedral Zn nodes. When the chelating 2,2′-bipy was introduced into the reaction system, a two-dimensional (2-D) puckered network 2was constructed, where 1-D pseudo-channels, similar to those in 1, are bridged by azide ions in an end-on (EO) mode. Employment of the linear bridging 4,4′-bipy ligand as the auxiliary ligand resulted in the formation of an unusual 3-D polymer 3, where the connection of Zn and tzp2−produces a 2-D network, which are further joined by 4,4′-bipy. The tzp2−ligands in 1–3show the flexible conformations and different coordination modes, with the tetrazolate group being the 1,4-Nmode and the carboxylate group being the syn–anti, syn–synand monodentate mode, respectively. The results suggest that the flexible nature of the tzp2−ligand as well as the introduction of auxiliary ligands is responsible for the formations of 1–3. Their photoluminescent properties and thermal stabilities have also been discussed. [ABSTRACT FROM AUTHOR]