Transition-metal ion complexes containing perchlorate groups and pyridine or substituted pyridines

Abstract

A series of complexes of the general formula [CoL₄(ClO₄)₂] have been prepared and studied; L = pyridine (py), 3-methylpyridine (3-Mepy), 4-methylpyridine (4-Mepy), 3,5-dimethylpyridine (3,5-Me₂py), 4-ethylpyridine (4-Etpy), 3-ethyl-4-methylpyridine (3-Et-4-Mepy), 4-n-propylpyridine (4-Prⁿpy), 4-isopropylpyridine (4-Prⁱpy), or 3-bromopyridine (3-Brpy). Also prepared were [Mn(py)₄(ClO₄)₂], [Cu(py)₄(ClO₄)₂], and [Zn(py)₄](ClO₄)₂. Magnetic susceptibility measurements, infrared spectra, and near-infrared and visible absorption spectra show that the solid Co(II) complexes are tetragonally distorted octahedral species. However, the pyridine base solutions of the complexes display bands typical of a regular octahedral arrangement of ligands about cobalt(II). D_q and B_complex values were calculated from the visible and near-infrared spectral data.