IMMOBILIZATION AND PHOTOACOUSTIC-SPECTROSCOPY OF N-(2-PYRIDYL)ACETAMIDE CATION COMPLEXES BONDED TO SILICA-GEL

N-(2-Pyridyl)acetamide was covalently immobilized onto silica gel giving 1.57 x 10(-4) mol of this molecule per gram of silica. This new bidentate chelate extracts MCl2 (M = Ni, Co, Cu) from ethanol and acetone solutions. The photoacoustic spectra of the solid complexed samples were obtained in the visible and near-infrared spectral regions and were analysed using ligand field theory. The calculated Racah parameters indicate a tetrahedral geometry for nickel and cobalt and a highly distorted octahedral geometry for the copper complex.