Tuning zinc(II) coordination architectures by rigid long bis(triazole) and different carboxylates: Synthesis, structures and fluorescence properties

Three metal-organic coordination polymers containing rigid bis(triazole) ligand, namely, [Zn1.5(btb)(nbta)(H2O)]n (1), {[Zn(btb)(3-nph)]·(H2O)}n (2) and [Zn(btb)(4-nph)]n (3) (btb=4,4'-bis(1,2,4-triazolyl-1-yl)-biphenyl, 3-H2nph=3-nitrophthalic acid, H3nbta=5-nitro-1,2,3-benzenetricarboxylic acid, and 4-H2nph=4-nitrophthalic acid) were synthesized under hydrothermal conditions and structurally characterized by X-ray single-crystal diffraction. Complex 1 possesses an interesting 3D coordination framework with a rarely binodal (4,4)-connected frl topological structure. Complexes 2 and 3 exhibit similiar 2D (4,4) grid layers with different point symbol (4(4)·6(4)) in 2 and (4(4)·6(2)) in 3. Furthermore, thermal stability of these compounds has been discussed. Complexes 1-3 exhibit strong solid-state fluorescence at room temperature in solid state.

catena-Poly[hexaaquamagnesium(II) [bis(μ3-5-nitro-2-oxidoisophthalato)dicopper(II)] dihydrate]

In the centrosymmetric dinuclear anions of the title bimetallic complex, {[Mg(H(2)O)(6)][Cu(2)(C(8)H(2)NO(7))(2)]·2H(2)O}(n), each Cu(II) ion is strongly coordinated by four O atoms in a distorted square-planar geometry. Two of these O atoms belong to phenolate groups and the other two to carboxylate groups from 5-nitro-2-oxidoisophthalate (L1) trianions, derived from 5-nitrobenzene-1,2,3-tricarboxylic acid (O(2)N-H(3)L). The phenolate O atoms bridge the two Cu(II) ions in the anion. In addition, each Cu(II) cation interacts weakly with a symmetry-related carboxylate O atom of an adjacent L1 ligand, giving a square-pyramidal coordination geometry. The copper residue forms a ladder-like linear coordination polymer via L1 ligands. The [Mg(H(2)O)(6)](2+) cations sit on centres of inversion. The polymeric anions, cations and free water molecules are self-assembled into a three-dimensional supramolecular network via O-H···O hydrogen bonds.

Three Novel Polymeric CoII/CuII Complexes Assembled from 5-Nitro-1,2,3-benzenetricarboxylate and 4,4'-Bipyridine: Syntheses, Crystal Structures, and Magnetic Properties

To investigate the coordination behaviour of tricarboxylate ligands that always induced the formation of intriguing metal organic frameworks, three CoII/CuII complexes constructed with bi-/tri-nuclear secondary building units (SBUs), namely CoII3(O2N-btc)2(4,4′-bpy)3(H2O)2 (1), [CuII3(O2N-btc)2(4,4′-bpy)2(H2O)2]·2H2O(2) and [CuII5(O2N-btc)2(O2N-btcH)2(4,4′-bpy)2(μ2 -OH2)2(H2O)8]·4H2O(3) (O2N-btcH3 = 5-nitro-1,2,3-benzenetricarboxylate, 4,4′-bpy = 4,4-bipyridyl), were hydrothermally synthesized using O2N-btcH3 and 4,4′-bpy as ligands. Complexes 1 and 2 exhibit the 3D framework constructed from a binuclear [M2(COO)2] (M = CuII and CoII) unit and a mononuclear MII unit, displaying (4·6·8)2(64·82) (42·68·83·102) and (4·6·8)2(62·84) (42·62·810·12) topology, respectively. Complex 3 displays an interesting 2D ladder-layered network constructed from a trinuclear [Cu3(μ2-OH2)2] unit and a mononuclear CuII unit as the linking nodes, showing (42.6)2(46.66.83) nets. These compounds are well characterized by elemental analysis, FTIR, thermogravimetric analysis and powder X–ray diffraction. The direct current magnetic susceptibility measurements were carried out to study their magnetic properties.