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_(0.5)(tdc)_(0.5)(L)]_(2n)(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.