A novel copper organophosphonate with a pore-like 3D framework and Cu–Cu magnetic ordering

Abstract

H₂O₃PCH₂NH₂⁺CH₂PO₃H⁻ was hydrothermally reacted with Cu(II) in aqueous solution at a 1 : 1 ratio, forming Cu₃[NH₂(CH₂PO₃)₂]₂ (1). Two kinds of coordination environments exist around the central copper ions: a distorted square planar Cu(1) ion and an octahedral Cu(2) ion. They are bridged with one terminal oxygen atom forming a 3D-coordination framework of layers sharing corners. Novel antiferromagnetic coupling between the two kinds of Cu units was observed at 15 K, followed by ferromagnetic ordering at 9 K.