Solvothermal synthesis and magnetic properties of cobalt(II) phosphite structures of varying dimensionality

Abstract

Three new organically templated cobalt phosphites, [C₄N₂H₁₂][Co(HPO₃)₂] (1), [(C₄N₂H₁₂)_0.5(C₂NH₈)][Co₂(HPO₃)₃] (2) and [C₂NH₈]₂[Co₃(HPO₃)₄] (3) have been synthesized under solvothermal conditions templated by piperazine. Single-crystal structure analysis reveals that compound 1 displays a one-dimensional (1D) chain-like structure, containing corner-shared four-membered rings. In compound 2, the linkages between CoO₄ and HPO₃ units form an inorganic layer with 4- and 12-membered aperture, while in compound 3, corner-sharing CoO₄ and HPO₃ units give rise to a three-dimensional structure with 16-membered ring channels, in which organic amine cations reside. The presence of 4-membered rings and one-dimensional chain/ladder structures in all compounds shows that such units are vital for building up of higher dimensionality. The magnetic properties of the three compounds are also discussed.