Copper(ii) chlorofluorophosphate: a new layered square-net for intercalating amines

Abstract

Three copper(II) chlorofluorophosphates, synthesised in hydrofluorothermal conditions and characterised using single crystal X-ray diffraction, have been shown to adopt a new type of mixed-anion, layered structure. Identical two-dimensional, inorganic, square-nets, of the general formula [Cu₄Cl(PO₃(F,OH))₄]⁻, exist in all three compounds. Three different cationic species, [NH₄]⁺, [H-piperazine]⁺ and [H-1,4-diaminocyclohexane]⁺, can be incorporated between the inorganic layers and all three cations are oriented to hydrogen-bond to the anionic sheets. The [Cu₄Cl(PO₃(F,OH))₄]⁻ layers are constructed from a new type of secondary building unit formed from four ClCuO₄ square-based pyramids, connected via a μ⁴ bridging chloride ion, which are further linked via PO₃(F,OH) tetrahedra.