Orbital splittings of some tetragonal nickel(II) complexes with heterocyclic amine ligands

Abstract

Electronic spectra (5000–20,000 cm.^–1) are reported for some complexes of the types NiL₄X₂ and polymeric NiL₂X₂(where L = pyridine, isoquinoline, and 3- and 4-methylpyridine; X = Cl, Br, or I) at room temperature and, in some cases, at ca. 80°K. The bands due to the transitions ³A_2g→³T_2g and ³A_2g→³T_1g(F) in O_h symmetry are split. From the observed band splittings the relative d-orbital energies are deduced by use of electrostatic and molecular orbital models.