On the relationship between α-nickel hydroxide and the basic salts of nickel

alpha-Nickel hydroxide is isostructural with the hydroxide-rich basic salts of nickel. The anions in the basic salts are strongly grafted to the nickel hydroxide sheets, but in Lu-nickel hydroxide, the anions are loosely intercalated between the hydrated nickel hydroxide sheets, [Ni(OH)(2-x)(H2O)(x)](x+). The loose intercalation causes the sheets to become disordered and leads to a turbostratic structure. In contrast, the nickel hydroxy-anion sheets in the basic salts are stacked together in a highly ordered fashion. The basic salts of nickel transform into the alpha-hydroxide upon ageing in a tartarate buffer, into beta-hydroxide at pH 4, and into beta(bc) (bc: badly crystallized) phase in 1 M KOH. (C) 1998 Elsevier Science S.A.