A new two-dimensional Zn coordination polymer based on 1,3-bis(2-methyl-1H-imidazol-1-yl)benzene and 5-nitrobenzene-1,3-dicarboxylic acid: synthesis, crystal structure and physical properties.

A novel two-dimensional (2D) Zn coordination framework, poly[μ-1,3-bis(2-methyl-1H-imidazol-1-yl)benzenezinc(II)], [Zn(CHNO)(CHN)] or [Zn(NO-BDC)(1,3-BMIB)] [1,3-BMIB is 1,3-bis(2-methyl-1H-imidazol-1-yl)benzene and NO-HBDC is 5-nitrobenzene-1,3-dicarboxylic acid], has been prepared and characterized by IR, elemental analysis, thermal analysis and single-crystal X-ray diffraction. Single-crystal X-ray diffraction analysis revealed that the compound is a new 2D polymer with a 6 topology parallel to the (10-2) crystal planes based on left-handed helices, right-handed helical NO-BDC-Zn chains and [Zn(1,3-BMIB)] clusters. In the crystal, adjacent layers are further connected by C-H...O hydrogen bonds, C-H...π interactions, C-O...π interactions and N-O...π interactions to form a three-dimensional structure in the solid state. In addition, the compound exhibits strong fluorescence emissions in the solid state at room temperature.