The preparation and characterization of four-coordinate complexes related by electron-transfer reactions

Article abstract of DOI:10.1021/ic50010a031

The synthesis and characterization of a new series of four-coordinate complexes of the general type [MS₄C₄R₄]^z are described in detail. Three series of complexes have been obtained. With R = C₆H₅ and CF₃ and M = Ni three species have been obtained with z = 0, -1, and -2. With R = CN a series of new mononegative anionic complexes was prepared containing M = Cu, Co, Ni, Pd, Pt, and Au. The related species with z = -2 have been previously reported.^2,3 All known numbers of these three series are readily interconverted by electron-transfer reactions. Polarographic half-wave potentials for the oxidation-reduction couples are tabulated. The mononegative anions of Ni, Pd, and Pt contain the metal in the doublet spin state and have been examined by electron spin resonance. The initial observations of hyperfine splittings by Ni⁶¹, Pd¹⁰⁵, and Pt¹⁹⁵ are reported. The presence of three principal g-values in the glass spectra of the complexes demonstrates the marked deviations of the ligand fields in these complexes from axial symmetry.