Synthesis, characterisation and crystal structure of a three-dimensional network of an h-bonded Ni (II) Hexametylenetetramine complex

A three-dimensional network of H-bonding nickel (II) hexamethylenetetramine complex has been synthesized and characterised and its structure determined by single crystal X-ray diffraction studies which show that [Ni(H2O)6](HMTA)2Cl32.4H2O crystallizes in the triclinic crystal system with space group PĪ, a = 9.2955(4), b = 9.3187(2), c = 9.3996 Ǻ, α = 119.4160(10), β = 94.4940(10), ɣ = 100.8680(10)º, V =682.47(4) Å3 and z = 1. The nickel atoms are each bonded to six aquo ligands giving an octahedral geometry. The ligand hexamethylenetetramine (HMTA) and chloride ions are bonded to water molecules through hydrogen bonding. Thermal studies show a decomposition pattern corresponding to the loss of the coordinated and uncoordinated water molecules, chloride ions and HMTA ligand in the form of a mixture of gases

A One Pot Green Synthesis and Characterisation of Iron Oxide-Pectin Hybrid Nanocomposite

Copyright © 2013 Foba-Tendo J. Ngenefeme et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Nano-composites comprised of magnetite nanoparticles in a pectin matrix were prepared by the co-precipitation method. Both sodium hydroxide and ammonium hydroxide were used as precipitating agents and the effects of stoichiometric ratios of iron salts to polymer concentration on particle properties were investigated. The precipitates obtained with NH4OH were sponge-like. The XRD pattern revealed magnetite as the only iron oxide phase present when NH4OH was used as precipitating base whilst nanoparticles precipitated using NaOH showed the presence of additional peaks. The nanocomposites obtained were further characterized using transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), X-ray powder diffraction (XRD), and zeta-potential. FT-IR confirmed the COO-Fe linkage. Zeta-potential analysis showed a potential change from positive in pure magnetite to negative in polymer coated magnetite depending on the oxide-polymer ratio. SEM and TEM showed fairly evenly distributed nanosize pores