Structural Characterization of Cadmium Hexacyanometallates(II) and Related Complexes

Abstract

Cadmium hexacyanometallates (II) crystallize in the same monoclinic cell (space group C52h−P21/n) reported for the analogs of manganous complexes. In that monoclinic framework, two outer cations (M = Mn2+ or Cd2+) of neighboring structural units M2[LII(CN)6], (L = FeII, RuII, OsII), are linked by two common water molecules. On heating above 100°C, these water bridges are removed. In dehydrated complexes, the outer cation (M) remains linked to only three CN ligands. The loss of aquo-ligands induces a remarkable π-back donation from the inner cation (L) to CN ligands, which was studied using IR, Raman, and Mossbauer spectroscopies.