Dihydroxybenzoquinone and chloranilic acid derivatives of rare earth metals

Abstract

The crystal structures of lanthanide complexes involving the dianions of dihydroxybenzoquinone (H₂dhbq) or chloranilic acid (H₂can) are presented. The complexes, Ln₂dhbq₃·24H₂O (Ln = Y, La, Ce, Gd, Yb and Lu) are 2-D coordination polymers with metal centres linked by dhbq²⁻ ligands. Each of these species contain a Ln₂(H₂O)₁₈ pentagonal dodecahedral cage. Despite the variation in the radii of lanthanide ions this series is isostructural. In contrast, the hydrated structures of Ln₂can₃ (Ln = Sc, Y, La, Pr, Nd, Gd, Tb, Yb and Lu) show considerable structural variation. The crystal structures of the diamond-like networks Ycan₂⁻ and Thcan₂ are also presented.