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The merits of d(super 10) metal and pyridine-3,4-dicarboxylic acid are combined and two novel three-dimensional coordination polymers are synthesized. The strong photoluminescent properties of both these compounds make them excellent candidates for potential photoactive materials.

Research has been conducted on supramolecular assemblies produced by polyoxometalate and crown ether building blocks. The authors describe the synthesis and characterization of these assemblies via the use of elemental analyses, single-crystal X-ray diffraction, IR, UV-vis and TG.

We investigate mechanisms controlling the complex electrical conductivity of a porous media using noninvasive spectral induced polarization (SIP) measurements of a silica gel during a pH dependent surface adsorption experiment. Sorption of sodium on silica gel surfaces was monitored as the pH of a column was equilibrated at 5.0 and then successively raised to 6.5 and 8.0, but the composition of the 0.01 M NaCl solution was otherwise unchanged. SIP measurements show an increase in the imaginary conductivity of the sample (17.82 ± 0.07 μS/cm) in response to the pH change, interpreted as deprotonation of silanol groups on the silica gel surface followed by sorption of sodium cations. Independent measurements of Na+ accumulation on grain surfaces performed using a radioactive 22Na tracer support the interpretation of pH-dependent sorption as a dominant process controlling the electrical properties of the silica gel (R² = 0.99) and confirms the importance of grain polarization (versus membrane polarization) in influencing SIP measurements of silicate minerals. The number of surface sorption sites estimated by fitting a mechanistic, triple-layer model for the complex conductivity to the SIP data (13.22 × 1016 sites/m²) was 2.8 times larger than that estimated directly by a 22Na mass balance (5.13 × 1016 sites/m²), suggesting additional contributions to polarization exist. [ABSTRACT FROM AUTHOR]

Two novel nickel coordination polymers [Ni[sub 2](2,2′-bipy)[sub 2](OH)[sub 2](H[sub 2]btec)[sub 3n], (1) and [Ni[sub 2](1,10′-phen)[sub 2](H[sub 2]O)2[sub (]btec)][sub n] (2) (btec = 1,2,4,5-benzenetetracarboxylate) have been hydrothermally synthesized and characterized by elemental analyses, IR and XPS spectra, TG analysis, X-ray powder diffraction, and single crystal X-ray diffraction. Crystal data for 1: C[sub 90]H[sub 66]N[sub 12]O[sub 30]Ni[sub 6], monoclinic P2[sub 1]/c, a = 10.905(2) Å, b = 18.006(4) Å,, c = 20.551(4) Å, β = 94.91(3)δ, Z = 2. Crystal data for 2: C[sub 34]H[sub 22]N[sub 4]O[sub 10]Ni[sub 2], monoclinic P2[sub 1]/n, a: 10.122(2) Å, b = 9.3106(19) Å, c = 15.690(3) Å, β = 92.03(3)°, Z = 2. Compound 1 exhibits a novel one-dimensional chainlike structure, in which the dinuclear Ni centers are linked by the btec ligands. Furthermore, the adjacent chains are linked into a 2-D wavelike layer via the strong OH···O hydrogen bonding interactions. Compound 2 possesses an unusual two-dimensional steplike network with interesting rhombic grids. Both compounds exhibit unprecedented metal-organic ligand construction modes in {M/btec/L} (M = transition metal; L = chelate ligands) systems. The magnetic behaviors of compounds 1 and 2 have been studied. [ABSTRACT FROM AUTHOR]