A New Manganese Coordination Polymer Based on Azobenzene Tetracarboxylate and Auxiliary Pyridine Ligand:Synthesis,Crystal Structure and Magnetic Property

A new manganese coordination polymer(CP)has been synthesized under hydrothermal conditions.It’s formula is{Mn2(Oaobtc)(bpe)(H_(2)O)_(4)]}n,where H4Oobtc represents oxide azobenzene 2,2',3,3'-tetracarboxyl acid,and bpe is 1,2-bis(4-pyridine)ethylene.It was characterized by elemental analysis,infrared spectrum and X-ray single-crystal diffraction.The coordination polymer crystallizes in the monoclinic system,space group P2_(1)/c.The central ion was coordinated with H_(4)Oobtc ligands using bridging model,and carboxylic group connects two adjacent Mn(Ⅱ)ions into dimer units.The oxygen from carboxylates connect these dimer units into a one-dimensional(1D)chain,and N atoms from the bpe further expanded them into three-dimensional(3D)supramolecular edifice,eventually.Variable-temperature magnetic measurements of CP 1 indicate the presence of weak antiferromagnetic exchange between two nearest Mn(Ⅱ)ions with J=–0.367 cm^(-1).

Extended Network via π…π Interaction and Hydrogen Bond Linkages of 1D Copper(II) Coordination Polymer: Synthesis, Crystal Structure and Characterization of [Cu(4,4′-bpy)(2-pzc)- (H_2O)]ClO_4·H_2O (2-pzc=2-pyrazine-5-carboxylate;4,4′-bpy=4,4'-bipyridine)

A penta coordinated Cu(II) complex with mixed ligands 4,4′ bipyridine (4,4′ bpy) and 2 pyrazine 5 carboxylate anion (2 pzc), \[Cu(4,4′ bpy)(2 pzc)(H 2 O)\]ClO 4 ·H 2 O (1), has been solvothermally synthesized and characterized. Complex 1 crystallizes in the monoclinic space group P2 1 /n with a =0 82996(2) nm, b =1 58156(5) nm, c =1 53837(1) nm, β =103 536(2)°, V =1 96322(8) nm 3 , M r =478 30, Z =4, D c =1 618 g/cm 3 , final R = 0 0544 and wR =0 1487. The Structure of 1 indicates that the central Cu(II) atom is penta coordinated by two N atoms from two 4,4′ bpy ligands, and one N atom and one oxygen atom of the 2 pzc ligand in the equatorial plane, and one oxygen atom of the coordinated water molecule at the axial position. The coordination geometry of Cu(II) atom could be considered as a slightly distorted square pyramidal environment. The 4,4′ bpy ligands bridge the Cu(II) centers to form a one dimensional chain, and 2 pzc acts as a terminal chelated ligand, and π…π interaction between the pyrazine rings of 2 pzc ligands of adjacent chains links the chains into a 2D sheet. Furthermore, the hydrogen bonds among the oxygen atoms of the uncoordinated water molecules and the N atoms and O atoms of 2 pzc ligands and the oxygen atoms of the coordinated water molecules link the sheets into the ultimate 3D network of complex 1.