Synthesis, crystal structure and characterization of new three-dimensional Cu(II) coordination polymer based on 1,3,5-tris(imidazol-1-ylmethyl)benzene

Abstract

The title Cu(II) coordination polymer of 1,3,5-tris(imidazol-1-ylmethyl) benzene, namely {Cu(SO₄)(C₁₈H₁₈N₆)(C₂H₆O₂)}_n, was synthesized and characterized by elemental analysis, infrared spectra (IR), thermogravimetric analysis (TGA) and powder X-ray diffraction (PXRD) and single-crystal X-ray diffraction. Single crystal structure analysis shows that the title complex possesses a three-dimensional (3D) architecture with a very rare (3,4,6)-connected (4.6²)₂(4².6⁸.8³.10²)(6⁴.8²) topology . There are two kinds of crystallographically independent Cu^II centres, each lying on a centrosymmetric position and having a similar six-coordinated octahedral structure. One is coordinated by four N atoms from four 1,3,5-tris(-imidazol-1-yl)methyl benzene (timb) ligands and two O atoms from two different bridging sulfate anions. The second is surrounded by two timb N atoms and four O atoms, two from sulfate anions and two from two ethane-1,2-diol ligands. The tripodal timb ligand bridges neighbouring Cu^II centres to generate a two-dimensional layered structure. Adjacent layers are further bridged by sulfate anions, resulting in a three-dimensional structure. X-ray powder diffraction studies of the title complex confirm that there is no impurity phase in the bulk material since experimental diffraction patterns match well with the simulated ones. In addition, their thermal stabilities have also been investigated.

Keywords:

• Cu(II) complex
• 1,3,5-tris(imidazol-1-ylmethyl)-benzene
• solvothermal synthesis
• crystal structure

Acknowledgments

This work was supported by the he Scientific Research Foundation of Nanjing Polytechnic Institute (grant No. NHKY-2016–11).