Nanocrystalline Manganese Substituted Nickel Ferrite Thick Films as PPM Level H2S Gas Sensors

A simple sol-gel auto combustion technique is introduced for the synthesis of nanocrystalline manganese substituted nickel ferrite dry powders. These dry powders were mechano-chemically mixed with organic binders to prepare thixotropic pastes. Thixotropic pastes of as prepared ferrite powders were formulated and screen printed on glass substrates to form thick films, followed by firing at 450oC. The crystal structure, phase, surface morphology and topography of the samples were characterized by X-ray diffraction study, scanning electron microscopy, transmission electron microscopy, etc. The gas sensing behavior of the samples were characterized by exposing the films to various inflammable and toxic gases like LPG, NH3, CO2, ethanol, H2S and Cl2. It was found that the sensors made from the composition containing x=1.0, exhibits highly selective and most sensitive towards 20 ppm of H2S gas at 3500C. The effect of operating temperature, gas concentration, type of gases, etc. on gas response were studied and discussed. DOI: 10.17762/ijritcc2321-8169.15082

X-ray K-absorption studies of some schiff base copper oomplexes

770-771The chemical shifts and widths of copper K-edges are reported for some schiffbase copper complexes by means of X-ray absorption spectroscopy in which a Cauchris type bend spectrograph has been utilized. The metal-ligand distances have been computed using Levy's method. The results are examined to understand the nature of metal-ligand bonding. The observed linear relationships between chemical shifts (E, eV) and bond distance] (A) and edge width and metal-ligand electronegative differences have been interpreted in terms of changes in the degree of covalency of the metal-ligand bonding in the synthesised copper complexes

Synthesis and characterization of manganese(II), cobalt(II), nickel(II), copper(II) and zinc(II) complexes with 2-[2ʹ-hydroxy salicylidene 5ʹ-(4ʹ-phenyl,2ʹʹ-thiazolylazo)]benzoic acid and 2-[2'-hydroxy salicylidene 5ʹ-(4ʹʹ-phenyl, 2ʹʹ-thiazolylazo)] phenol

540-544Metal complexes of the type [M(L).2H2O]2 [L=2-[2'–hydroxy salicylidene 5ʹ-(4ʹ-phenyl,2ʹʹ-thiazolylazo)]benzoic acid (L1) and 2-[2ʹ-hydroxysalicylidene 5'-(4"-phenyl-2"-thiazolylazo)] phenol (L2)]; M= Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) have been synthesized and characterized by elemental analysis, magnetic susceptibility, molar conductance, TGA, X-ray diffraction and spectral studies. L1 and L2 acts as dibasic tetradentate ligands and the complexes appear to be octahedral. Antibacterial activities of ligands and their metal complexes have been determined against Escherichia coli, Bacillus substilis, Klebsiella Pneumoniae, Pseudomonas aerogens, Salmonella paratyphi B, Staphylococcus aureus and Proteus vulgaris.</i

Synthesis, characterisation and X-ray diffraction studies of 8-(4-phenyl-2-azothiazolyl)-7 -hydroxy-4-methylcoumarin

1203-1206New 8-(4-phenyl-2-azothiazolyl)-7-hydroxy-4-methylcoumarin (HL) has been synthesized by the diazotisation of 4-phenyl-2-aminothiazole and its consequent coupling with 7-hydroxy-4-methylcoumarin. HL has been characterised by elemental analysis, IR and NMR spectral data. X-ray diffraction study has been carried out and examined for its structural properties. The structure of HL has emerged as tetragonal non-primitive system. The compound is also found to be active against some bacterial and fungal species