Synthesis, Structures and Properties of Six Coordination Polymers of 1,3,5-Tri-4-pyridyl-1,2-ethenylbenzene

Reactions of the tri-olefinic tri-pyridyl ligand 1,3,5-tri-4-pyridyl-1,2-ethenylbenzene (tpeb) with four metal nitrates M(NO3)(2) (M=Co, Ni, Zn, Cd) and various carboxylic acids including 3,5-dibromobenzoic acid (3,5-HDBB), 2,5-thiophenedicarboxylic acid (2,5-H2TDC), 2,5-furandicarboxylic acid (2,5-H2FDC) and 2,5-dibromoterephthalic acid (2,5-H2DBTP) gave rise to six coordination polymers,namely [Zn(tpeb)(3,5-DBB)(2)](n) (1), [Co-2(tpeb)(2)(2,5-TDC)(2)](n), (2), [Co-2(tpeb)(2)(2,5-FDC)(2)](n) (3), [Co(tpeb)(2,5-DBTP)](n), (4), [Ni(tpeb)(2,5-DBTP)](n), (5) and [Cd(tpeb)(0.5)(2,5-DBTP)](n), (6). Complexes 1 similar to 6 were characterized by elemental analysis, infrared spectrum (IR), thermogravimetric analysis (TGA), powder X-ray diffraction (PXRD) and single crystal X-ray diffraction. Complexes 1 similar to 6 show rich structure varieties from one-dimensional (1D) to three-dimensional (3D). Compound 1 has a 1D zigzag chain structure in Which the [Zn(3,5-DBB)(2)] units are interconnected by tpeb ligands. Complexes 2 and 3 contain a similar two-dimensional (2D) double-layer network assembled from 1D ladder chains of [Co(tpeb)](n) bridged by 2,5-TDC or 2,5-FDC. Complexes 4 and 5 hold a 3D framework constructed by bridging 1D chains of [M (2,5-DBTP)](n), (M = Co, Ni) with tpeb ligands. Compound 6 contains 2D [Cd(2,5-DBTP)](n), networks, which are interlinked by tpeb bridges, forming a unique 3D framework. Complexes 1 similar to 6 have good thermal stability, and exhibit various fluorescence emissions in the solid state. CCDC: 1981275, 1; 1902623, 2; 1902624, 3; 1902626, 4; 1902627, 5; 1981276, 6.