Assembly of Five Coordination Polymers Based on Furan-2,5-dicarboxylic acid and 4,4′-Azobispyridine: Synthesis, Structures and Luminescence Properties

Five coordination polymers (CPs) {[Zn 4 (FDA) 4 (H 2 O) 12 ]} n ( 1 ) {[M(FDA)(azopy)·DMF]} n ( 2 ) [M = Zn ( 2a ), Co ( 2b ) and Cd ( 2c )] and {[Zn(FDA)(azopy)]·CH 3 CN·0.5DMF} n ( 3 ) have been harvested from furan-2,5-dicarboxylic acid (H 2 FDA) and 4,4′-azobispyridine (azopy), and structurally characterized by infrared spectra, elemental analysis, thermogravimentric analysis, powder X-ray diffraction and single-crystal X-ray diffraction. CP 1 shows an interesting one-dimension chain structure. CP 2a and CP 2b are isostructural and demonstrate two-dimensional 4-connected sql topological structures where FDA 2− connected the nearest Zn(II) ions to generate a one-dimension chain and the chains could be further linked by azopy. CP 2c significantly differs from CP 2a and CP 2b in coordination number as well as in the coordination mode of carboxylate groups. However CP 2c can generate the same two-dimensional sql structure as well. While CP 3 is an interesting pillared-layer three-dimensional two-fold interpenetrating framework with a pcu alpha-Po primitive cubic topology. The luminescence properties of CP 1 , CP 2a, CP 2c and CP 3 are investigated.