Synthesis and characterization of chitosan/ZnO nanoparticle composite membranes.

Novel chitosan/ZnO nanoparticle (CS/nano-ZnO) composite membranes were prepared via the method of sol-cast transformation and studied by UV-vis absorption spectroscopy (UV-vis), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray fluorescence spectrometry (EDX). The characterization revealed that ZnO nanoparticles dispersed homogeneously within the chitosan matrix. The mechanical and antibacterial properties of the product were investigated.

catena-Poly[[[tetra-aqua-zinc(II)]-μ-4,4'-bipyridine-κN:N'] benzene-1,4-di-carboxyl-ate].

In the title compound, {[Zn(C(10)H(8)N(2))(H(2)O)(4)](C(8)H(4)O(4))}(n), the Zn(II) atoms, lying on a twofold rotation axis, are bridged by 4,4'-bipyridine ligands, resulting in a linear chain along the b axis. In the chain, the Zn(II) atom adopts a slightly distorted octa-hedral coordination geometry involving four water mol-ecules at the equatorial positions. The noncoordinated benzene-1,4-dicarboxyl-ate anion, which is also located on a twofold rotation axis, bridges adjacent chains through O-H⋯O hydrogen bonds, forming a three-dimensional supra-molecular network.

1,1'-Dimethyl-4,4'-(propane-1,3-di-yl)dipyridinium tetra-bromidocadmate(II).

In the cation of the title compound, (C(15)H(20)N(2))[CdBr(4)], the dihedral angle between the two pyridine rings is 70.85 (5)°. An inter-molecular π-π inter-action between the pyridine rings [centroid-centroid distance = 3.

1,1'-Dimethyl-4,4'-bipyridinium bis-(tetra-fluorido-borate).

In the title compound, C(12)H(14)N(2) (2+)·2BF(4) (-), the cation has a centre of symmetry at the mid-point of the central C-C bond. π-π inter-actions, with a shortest atom-to-atom distance of 3.757 (4) Å, extend the crystal structure into a one-dimensional supra-molecular chain.

5-Amino-3-(4-pyrid-yl)isoxazole.

In the title compound, C(8)H(7)N(3)O, there are two independent mol-ecules in the asymmetric unit, in which the angles between the pyridine ring and the isoxazole ring are 35.8 (6) and 10.6 (2)°.