Synthesis,Crystal Structure and Theoretical Calculations of a Manganese(Ⅱ) Coordination Polymer Assembled by 2,5-Thiophenedicarboxylic Acid and 3-(2-Pyridyl)pyrazole Ligands

A new Mn（Ⅱ） complex, [Mn;（tdc）;（L）];(1, H2 tdc = 2,5-thiophenedicarboxylic acid, L = 3-（2-pyridyl）pyrazole), has been successfully synthesized under hydrothermal conditions. Its structure has been determined by single-crystal X-ray diffraction analysis, elemental analyses, IR, TG and UV spectrum. Single-crystal X-ray diffraction analysis reveals that complex 1 belongs to the orthorhombic system, space group Pnna with a = 11.5184（6）, b = 16.8399（8）, c = 11.7249（5） ?, V = 2274.26（19） ?3, Z = 4, D3c = 1.505 g/cm, μ = 0.715 mm-1, Mr = 515.41, F（000） = 1052, the final R = 0.0336 and w R = 0.0802 with I > 2σ（I）. It exhibits a one-dimensional zigzag-chain structure, which was stabilized through intermolecular C–H···O and intramolecular N–H···O hydrogen bonding interactions. Moreover, we analyzed Natural Bond Orbital（NBO） by using the PBE0/LANL2 DZ method built in Gaussian 09 Program. The calculation results showed obvious covalent interaction between the coordinated atoms and Mn（Ⅱ） ion.