Di-2-pyridyl ketone/benzoate/azide combination as a source of copper(II) clusters and coordination polymers: dependence of the product identity on the solvent

The reactions of di-2-pyridyl ketone with Cu(O2CPh)2 in the presence of NaN3 and LiOH have led to an antiferromagnetically coupled (S = 0) Cu(II)6 cluster with a novel core and to (Cu(II)8)n and (Cu(II)2)n coordination polymers (the former 1D and the latter 2D) with interesting structures. The cluster or polymer formation depends on the reaction solvent.     

Oscillator models for multiphoton optical bistability and phase conjugacy

Nonlinear oscillator models are constructed to treat the bistability in situations involving elementary excitations in solids. Such models are shown to be useful not only in describing single photon but also multiphoton bistability. The resulting bistability both with and without cavity is considered. The two-photon excitonic bistability in CuCl is in detail. The effect of local field corrections can also be incorporated, in a simple manner, in such models.     

Directed assembly and reactivity of olefins within a one-dimensional ladder-like coordination polymer based on a dinuclear Zn(II) platform

A ladder-like coordination polymer involving a dinuclear Zn Schiff-base complex possesses organic linkers that undergo [2+2] photodimerisation in the solid state.     

Determination of acetaldehyde in liquid, solid and semi-solid food after pervaporation-derivatization

 A spectrophotometric method for the determination of acetaldehyde in liquid, semi-solid and solid food samples, employing the coupling of a continuous flow configuration to a pervaporation unit, has been proposed. It is based on the reaction of the analyte with fuchsin in acidic medium and subsequent formation of a coloured product (alkylsulphonic acid chromophore) with sodium sulphite, which was monitored spectrophotometrically. Variable sensitivity was obtained by altering the pervaporation temperature and the thickness of the membrane. The detection limits went down to 4.2 μg/mL and the precision was between 1.2 and 3.6%. Received: 5 August 1996/Revised: 16 October 1996/Accepted: 18 October 1996     

Flow-injection/pervaporation coupling for the determination of sulphide in Kraft liquors

A dynamic manifold has been coupled with a pervaporation module for the determination of sulphide ion in complex matrices such as Kraft liquors. The method is based on ethylene blue formation and features detection limits of 0.68 and 0.42 microg mL(-1) of S(2-) for injection and continuous introduction of the sample, respectively, with linear ranges of 1-15 and 1-10 microg mL(-1). The method is highly selective as the interferences from other sulphur species are avoided in the pervaporation process; thus, it has been applied successfully to the determination of the analyte in white and green bleaching liquors.     

Crystal and molecular structure of [Cu2(3,5-dihydroxybenzoate)4 (acetonitrile)2] ⋅ 8H2O

The crystal and molecular structure of the title compound, [Cu₂(3,5-dihydroxybenzoate)₄ (acetonitrile)₂] 8H₂O 1, is reported. Crystal data for 1: tetragonal, space group I 4/m, a = 11.720(2) Å, c = 15.304(3) Å, V = 2102.4(6), and D _c = 1.53 g/cm³, for Z = 2. The metal and organic components crystallize to form a Cu paddle-wheel complex, of idealized D_4h symmetry, that assembles in the solid-state, along with eight equivalents of water, to form a 3D hydrogen-bonded network held together by O–H O hydrogens bonds. The metal complexes pack to form a 2D layered structure.