Polarized Crystal Spectra of Some Nickel(II)Cyanide Complexes

Abstract

In order to settle some questions as to the bonding in square -planar nickel complexes the following compounds were investigated: $${\text{N}}{{\text{a}}_{\text{2}}}{\text{Ni(CN}}{{\text{)}}_{\text{4}}}{\text{.3}}{{\text{H}}_{\text{2}}}{\text{O}}\;{\text{and}}\;{{\text{K}}_{\text{2}}}{\text{Ni(CN}}{{\text{)}}_{\text{4}}}{\text{.3}}{{\text{H}}_{\text{2}}}{\text{O}}$$ which are isomorphous having triclinic symmetry, $$CaNi{\left( {CN} \right)_4}.5{H_2}O$$ which is orthorhombic and $$SrNi{\left( {CN} \right)_4}.5{H_2}O$$ both being monoclinic. The polarized spectra were measured with the light parallel and perpendicular to the c-axis; this axis being nearly, but not quite perpendicular to the planes of the nickel cyanide complexes. The spectra were measured both at room tem¬perature and at liquid nitrogen temperature.