Structural and Magnetic Properties of the Topologically Novel 2-D Material Cu₉F₂cpa)₆: A Triangulated Kagome - Like Hexagonal Network of Cu(II) Trimers Interconnected by Cu(II) Monomers

Abstract

Abstract Cu9F2(cpa)6 xH2O (cpa = carboxypentonic acid) has been synthesized, and characterized by x-ray diffraction. It is isomorphous with the CI and Br congeners. Two coordinatively different Cu(II) ions comprise the unit cell: six Cutrimer (square pyramidal) and three Cumonomer (elongated octahedra). The six Cut ions form two exchange coupled trimeric clusters. Each of these trimers is bridged to three Cum sites; each Cum is connected to two trimers. The extended lattice is a hexagonal network with trimers at the vertices and Cum ions along the edges. Magnetic field-dependent magnetic susceptibility studies in the range 1.7 – 300 K demonstrate that the compound has a magnetic ground state which is highly field dependent at lower temperatures (< 20K). The interconnected triangulation suggests spin frustation. Theoretical results for this type of lattice are unknown, but analogies can be drawn to the Kagomé lattice.