Electrical conductance and ion pair formation of Co [III] complexes of acetylpyridinethiosemicarbazone halides in ethanol-water mixtures at 25C

The conductance of [III] complexes of acetylpyri-dinethiosemicarbazone halides were measured in ethanol-water mixtures covering a range of dielectric constant 24.33 < D < 78.54 at 25C. The conductance parameters derived from the Fuoss-Onsager conductance theory indicate that the solvation of these halides decreases with the decrease of the dielectric constant until a certain minimum and then increases again. The plots of log Ka vs. 1/D are not linear indicating that the solvent separated-ion pairs in these systems are characterized by strong hydrogen bonding

Thermodynamic studies on some aqueous-amides

The thermodynamic dissociation constant of p-nitro-anilinium ion pK[BH][+], was calculated in aqueous, -formamide, -acetamide and -propionamide solvent, it was found that the order of basicity of such mixtures is in agreement with the electron availability at the oxygen atom of the amide molecule. The calculated values of the free energy of transfer indicate that, the addition of the amide increases the basicity of water molecules. The equilibrium constant K'[b]of the equilibrium, H[3] O[+] [amide] [amide]. H[+] +H[2]O, is calculated which indicates that the basicity increases in the order formamide < acetamide < propionamide. The free energies of transfer delta Gt[0] [H+], of the solvated proton, from water to aqueous amide show that propionamide has a higher ability to replace a water molecule in the aquo-proton than formamide