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The title mononuclear ZnII complex, [ZnCl2(C15H13N5)2], is isotypic with the previously reported HgII complex. The ZnII atom is located on a twofold rotation axis and has a distorted tetra­hedral environment of two Cl atoms and two N atoms from two heterocyclic ligands. In the crystal, complex mol­ecules are extended by inter­molecular π–π inter­actions [centroid–centroid distance = 3.792 (2) Å] into a three-dimensional supra­molecular network.

Source of materialTo a solution of 4,5-bis(2-hydroxyethylsulfanyl)-1,3-dithiole-2-thione [1] (2.86 g, 10 mmol) and CBr 4(8.3 g, 25 mmol) in dichloromethane (100 ml) was drop-added a solution of PPh 3 (6.56 g, 25 mmol) in the same solvent (20 ml) within 2 hours. The mixture was stirred at room temperature for 7 hours. The resulting solution was washed with water and dried over Na 2SO4. The solvent was then evaporated under reduced pressure and the crude product was purified by column chromatography (dichloromethane : petroleum ether = 2 : 3) to afford the title compound as yellow solid. DiscussionDuring the past decades, tetrathiafulvalene (TTF) and its derivatives (TTFs) as building blocks in both conducting molecular materials and supramolecular chemistry [2-4] have been attracted increasing attention since the discovery of the first metallic charge transfer (CT) complex between TTF and 7,7,8, [5]. On account of the hybrid organic-inorganic materials, CT salts based on TTFs have been widely investigated in the search for new and improved superconducting CT complexes and radical cation salts [6,7].TTFs serve as important p-electron donors for the development of molecular-based organic metals and superconductors, and a variety of studies on modification of the TTF skeleton have been made [8][9][10]. There are many routes for the preparation of TTFs. Generally, the most widely used is the coupling of two identical or non-identical 1,3-dithiole-2-(thi)ones mediated by a trivalent phosphorus derivative [11]. As important precursors of TTF derivatives, 1,3-dithiole-2-thiones have also attracted attention [12]. In the molecule of the title compound, the bond lengths and angles are within normal ranges [13]. In the crystal structure, adjacent molecules are linked by weak intermolecular C−H···S interactions (C···S distances: 3.7676(4) and 3.7932(4) Å, respectively) [14] into a chain, which extends into a two dimensional supramolecular architecture via weak inter-chain interactions of Br···Br (Br···Br distances: 3.731(1) and 3.889(1) Å, respectively) [13]. The adjacent layers are further interconnected into a interleaved three-dimensional supramolecular architecture by weak interactions of S···S and Br···S, with S···S distance range from 3.527(2) to 3.796(2) Å and a Br···S distance of 3.700(2) Å [13]. In addition, dipole-dipole and van der Waals interactions are also effective in the molecular packing.

Source of materialThetitle compound was prepared under the hydrothermalconditions. Am ixture of CoCl 2 ·6H 2 O( 0.1 mmol, 23.7 mg), benzoic acid (0.1 mmol, 12.2 mg) and 4,4'-bis-(1,2,4-triazol-1-ylmethyl)biphenyl (btmb, 0.1 mmol, 31.6 mg) in distilled water (10 mL) was placed in a25mLTeflon-lined stainless steelvessel, which was heated at 130°C for three days, and then cooled to room temperature. Red block-shaped crystals were obtained. Experimental detailsHatoms were generatedgeometrically, and refined as riding atoms, with C-H=0.93Å(CH)and 0.97 Å(CH 2 ). Hatoms bound to Oatoms were foundfromdifferencemaps and refined with distancerestraintsofO-H =0.85 Å. All Hatoms were refined with U iso (H) =1.2 U eq (C, O). DiscussionConsiderable interest continues to be focused on the rational design and syntheses of novel coordination polymers, because of their intriguing architectures and their potential applications as functional materials [1,2].Auseful strategy to synthesize such networked compounds involves the selection of appropriate multidentate bridging ligands and metal ions displaying appropriate electronic and steric properties that will act in concert to promote the formation of desired polymeric architectures [3][4][5]. Thus, the flexible triazole-containing ligand 4,4'-bis-(1,2,4-triazol-1-ylmethyl)biphenyl(btmb) has widely been utilized to construct coordination polymers because of its variable conformations and versatile coordination modes [6][7][8][9]. Herein we present the title polymeric compound [Co(C 18 H 16 N 6 )(C 7 H 5 O 2 ) 2 (H 2 O) 2 ] n (I), assembled from btmb, benzoic acid and Co II.The asymmetric unit of (I)containsone Co II ion, onebenzoate ligand,halfabtmb ligand andone coordinated watermolecule. Each Co II ion lies on an inversion centre, and adopts adistorted octahedral geometry with two Natoms from two symmetry-related btmbligands and two Oa toms from two benzoate ligands in the equatorial positions and two water Oa toms in the axial positions. Each btmb ligand adopts atrans conformation bridging two Co II ions to generateazigzagpolymer chain. Furthermore, thechains of (I)are furtherl inkedt ogethert hrough interchain O-H···Oh ydrogen bonds between the coordinated water molecules and the carboxylate oxygen atomsw ith the O···O distance of 2.828 Å along the ab plane to produce an infinite two-dimentional layer.

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