Spin-free six-coordinate
complexes of nickel(II) and the heterocyclic ligands 2-aminomethylpyridine, 2-methylaminomethylpyridine, 2-(2- aminoethyl)pyridine, and
2-aminomethyl-6-methylpyridine have been prepared and studied. Various hydrated
and anhydrous nickel(II) complexes with the anions sulphate, nitrate, halide,
and perchlorate were obtained with nickel ion to ligand stoicheiometric ratios
of 1 : 1, 1 : 2, and 1 : 3, and in a number of instances water molecule and
anion attachments to the coordination sphere are reported; the sulphate
complexes are considered to be of the bridged type. Also, certain mixed-ligand
solid complexes and mixed-ligand cationic species in aqueous solution were
prepared. Physical measurements used to elucidate structures included molecular
conductances in suitable solvents, solubility observations, infrared
spectrophotometry, pyrolysis methods, and measurements of magnetic
susceptibility. Complex cations in aqueous solution were characterized by
visible and near-infrared spectrophotometry.
Application of near-infrared spectrophotometry to determination of drugs. (I). Rapid assay of cefaclor in mixed powders.