Metal(II) Coordination Polymers Derived from Bis-pyridyl-bis-amide Ligands and Carboxylates: Syntheses, Topological Structures, and Photoluminescence Properties

Using bis-pyridyl-bis-amide ligands N, N ′-bis-(4-pyridyl)phthalamide ( L1 ), N, N ′-bis-(4-pyridyl)iso -phthalamide ( L2 ), hexanedioic acid bis-pyridin-4-ylamide ( L3 ), and carboxylates, six metal(II) complexes formulated as Cd 2 (1,4-chdc)(L1) 2 ·4H 2 O (1,4-H 2 chdc = 1,4-cyclohexanedicarboxylic acid) ( 1 ), Cd 2 (L1) 2 (in) 4 ·3DMF (Hin = isonicotinic acid) ( 2 ), Zn(L1)(1,4-bdc) (1,4-H 2 bdc = 1,4-benzenedicarboxylic acid) ( 3 ), Cd(L2)(1,4-chdc) ( 4 ), Zn 2 (L2) 2 (tdc) 2 ·DMF (H 2 tdc = thiophene-2,5-dicarboxylic acid) ( 5 ), and Zn(2,6-ndc) 0.5 (L3) 0.5 (SO 4 )·(CH 3 NHCH 3 ) (2,6-H 2 ndc = 2,6-naphthalene- dicarboxylic acid) ( 6 ) have been hydro(solvo)thermally synthesized and structurally characterized by single-crystal X-ray diffraction. Complex 1 is a uninodal 6-connected noninterpenetrated three-dimensional (3D) network with {4 4 .6 10 .8}- mab topology, complex 2 exhibits a uninodal 6-connected 2-fold interpenetrated 3D framework with {4 12 .6 3 }- pcu topology, complex 3 shows a uninodal 8-fold interpenetrated 3D diamondoid framework, complexes 4 and 5 possess similar uninodal 2D layer with 4 4 - sql topology, and complex 6 shows a framework of 2D → 3D inclined polycatenation based on 4 4 - sql layer. The six complexes show different thermal stability and photoluminescence properties. The emission band of complex 1 becomes strong after dehydration, and water can reduce the emission intensities of the six complexes to some extents.