Synthesis, crystal structure and properties of a copper(II) complex with 2,2'-dimethoxy-4,4'-biphenyldicarboxylic acid

A copper(II) complex, [Cu ₄L ₄(H ₂O) ₉]•10H ₂O (1), (H ₂L=2,2'-dimethoxy-4,4'-biphenyldicarboxylic acid), was synthesized and characterized by FT-IR, TGA, powder and single crystal XRD. The complex crystallizes in orthorhombic system with space group Pnma, a=1.493 9(3) nm, b=3.051 6(6) nm, c = 1.569 4(3) nm, V=7.154(2) nm ³, E=4 with final F=0.040 6. The complex contains four crystallographically distinct Cu(II) ions and each Cu(II) ions locates in a square-pyramid environment. Three μ ₂-bridging water molecules connect the four Cu(II) ions to form a short zigzag chain which is further joined by the L ligands to generate a 2D layer. A lot of hydrogen bonds assemble the 2D layer into a 3D supramolecular structure. The TG analysis shows that the complex is stable below 295 °C. Magnetic susceptibility measurement indicates that there is a weak antiferromagnetic exchange coupling between the Cu(II) ions. CCDC: 872818, 1.