Syntheses, Crystal Structures and Magnetic Properties of Two Copper(II) and Manganese(II) Coordination Compounds Constructed from Biphenyl Tricarboxylic Acid

Zero dimensional dinuclear copper (II) coordination compound and 3D manganese (II) coordination polymer, namely [Cu-2(Hdppa)(2)(4,4 '-bipy)(H2O)(4)]center dot 4,4 '-bipy center dot 6H(2)O (1) and {[Mn-3(mu(5)-dppa)(2)(4,4 '-bipy)(H2O)(2)]center dot 4H(2)O}(n) (2), have been constructed hydrothermally using H(3)dppa, 4,4 '-bipy (H(3)dppa=5-(3,4-dicarboxylphenyl)picolinic acid, 4,4 '-bipy=4,4 '-bipyridine), and copper or manganese chlorides. Single-crystal X-ray diffraction analyses revealed that two compounds crystallize in the triclinic or monoclinic system, space group P (1) over bar or C2/c. In compound 1, one 4,4 '-bipy ligand bridges neighboring Cu(II) ions to form a discrete dinuclear copper(II) structure. These Cu2 units are assembled to a 3D supramolecular framework through O-H center dot center dot center dot O/N hydrogen bond. In compound 2, neighboring Mn(II) ions are bridged by the carboxylate groups of mu(5)-dppa(3-) ligands, producing a double-helix Mn(II) chain subunit. The adjacent double-helix chains subunits are further linked by the dppa(3-) blocks and 4,4 '-bipy ligands into a 3D framework. Magnetic studies for compound 2 demonstrate an antiferromagnetic coupling between the adjacent Mn (II) centers. CCDC: 1814154, 1; 1814155, 2.