Complex of Tris(Phenanthroline)Cobalt(II)Trifluoroacetate: Characterisation and Powder XRD Analysis

The powder complex of tris(phenanthroline)cobalt(II) trifluoroacetate (TFA) has been prepared by interaction of cobalt(II) nitrate, phenanthroline (phen) in aqueous solution with drops of ethanol, and an excess of saturated aqueous solution of sodium trifluoroacetate, whereupon the yellowish powder was produced. AAS measurment for the metal content, equivalent conductance (1:2), and TGA-DTA of the powder suggest the corresponding formula of [Co(phen)3](TFA)2.5H2O. The efffective magnetic moment of 4.9 BM indicates the high-spin nature of this complex which corresponds to three unpaired electrons in the electronic configuration of Co(II) with significantly higher than the spin only value due to the orbital contribution. UV-Vis spectrum of the complex reveals the d-d spin-allowed transition bands as well as the MLCT and intraligand band. The estimating transition energy ratio of 2.04 for ν2/ν1, is clearly in the range for octahedral configuration. The infrared spectral property indicates the main mode of vibrations for the functional groups of ligand phen and TFA, and thus supports strongly the formula proposed for this complex. The corresponding powder XRD was then refined using Rietica-Le Bail method and found to be fit as triclinic crystal system with space group of PĪ.

Thermal Properties of Composite Polymer Electrolytes Poly(Ethylene Oxide)/Sodium Trifluoroacetate/Aluminum Oxide (PEO)10CF3COONa + x wt.% Al2O3

Polymeric membranes of poly(ethylene oxide) (PEO) and sodium trifluoroacetate (PEO:CF3COONa) combined with different concentrations of aluminum oxide (Al2O3) particles were analyzed by impedance spectroscopy, differential scanning calorimetry (DSC) and thermogravimetry (TGA). DSC results show changes in the crystalline fraction of PEO when the concentration of Al2O3 is increased. TGA analysis showed thermal stability up to 430 K showing small changes with the addition of alumina particles. The decrease in crystalline fraction for membranes with low Al2O3 concentration is associated with the increase in conductivity of (PEO)10CF3COONa + x wt.% Al2O3 composites.

Electrochemical Trifluoromethylation of Isonicotinic acid hydrazide using Cyclic Voltammetry and Galvanostatic Electrolysis

Trifluoromethylation of isonicotinic acid hydrazide has been investigated in trifluoroacetic acid containing pyridine, triethylamine and sodium trifluoroacetate dissolved in acetonitrile on platinum and glassy carbon electrodes using cyclic voltammetry. LSVs for isonicotinic acid hydrazide in 0.1 M TFA/ Py/TEA/NaTFA in acetonitrile on platinum electrode show that there is no distinct oxidation peak for the oxidation of isonicotinicacid hydrazide within the voltammetric region of 0.0 to 1.6 V vs Ag and it gets oxidized anodically in the gas evolution region itself. TFA/ NaTFA medium shows slightly higher current density than the other two media for the oxidation of isonicotinic acid hydrazide. CVs for different concentrations of isonicotinic acid hydrazide show that anodic peak becomes broad and flat. It shows that severe adsorption of INAH/product takes place on the glassy carbon electrode during the voltammetry scanning. Galvanostatic electrolysis of INAH in TFA/Py/ACN medium at low current density on Pt shows good conversion with low selectivity.