Synthesis and Crystal Structure of a New Copper(II) Coordination Polymer [Cu(II)C16H18N4O4S]n

A new one-dimensional [CuC16H18N4O4S](n)(1) was synthesized by the self-assembly of a ligand 2,5-thiophenediformates, 3,5-dimethylpyrazole and copper(II), and characterized by elemental analysis, M. and single-crystal X-ray diffraction. 1 crystallizes in monoclinic, space group C2/c with unit cell parameters, a=18.6156(4), b=5.96110(10), c= 18.1598(4), angstrom=115.467(2)degrees,Z=4, V=1819.37(7)angstrom(3), Mr = 425.94, De = 1.555g/cm(3), mu=1.345 mm(-1), and F(000)= 876. The final R and wR are 0.0328 and 0.0816 for 7611 observed reflections with I>2 sigma(I) shows an infinite 1-D polymeric chain structure based on the repeated basic units Cu(II)(3,5-dimethylpyrazole)(2)(2,5-thiophene diformate). The Cu(II)center acts as the joint of the unit, and is coordinated in a slightly distorted octahedral geometry comprised of four 0 atoms from two different 2,5-thiophenediformate ligands and two N atoms of two trans 3,5-dimethylpyrazole ligands.