Cd(II)/Mn(II)/Co(II)/Ni(II)/Zn(II) Coordination Polymers Built from Dicarboxylic Acid/Tetracarboxylic Acid Ligands: Their Structural Diversity and Fluorescence Properties

Six Cd(II)/Mn(II)/Co(II)/Ni(II)/Zn(II) coordination complexes are formulated as [Cd(2)(X(2−))(2)(μ(3)-O)(2/3)](n) (1), [Mn(2)(X(2−))(2)(μ(3)-O)(2/3)](n) (2), {[Co(1.5)(Y(4−))(0.5)(4,4′-bpy)(1.5)(OH(−))]·2H(2)O}(n) (3), {[Ni(X(2−))(4,4′-bpy)(H(2)O)(2)]·4H(2)O}(n) (4), [Zn(m-bdc(2−))(bebiyh)](n) (5), and [Cd(5-tbia(2−))(bebiyh)](n) (6) (H(2)X = 3,3′-(2,3,5,6-tetramethyl-1,4-phenylene) dipropionic acid. H(4)Y = 2,2′-(2,3,5,6-tetramethyl-1,4-phenylene)bis(methylene) dimalonic acid, bebiyh = 1,6-bis(2-ethyl-1H-benzo[d]imidazol-1-yl)hexane, m-H(2)bdc = 1,3-benzenedicarboxylic acid, and 5-H(2)tbia = 5-(tert-butyl)isophthalic acid) were obtained by hydrothermal reactions and structurally characterized. Complexes 1 and 2 have a 6-connected 3D architecture and with several point symbols of (3(6)·4(6)·5(3)). Complex 3 features a 5-connected 3D net structure with a point symbol of (5·6(9)). Complex 4 possesses a 4-connected 2D net with a vertex symbol of (4(4)·6(2)). Complex 5 is a 3-connected 2D network with a point symbol of (6(3)). Complex 6 is a (3,3)-connected 2D network with a point symbol of (6(3))(2). In addition, complexes 1 and 4 present good photoluminescence behaviors. The electronic structures of 1 and 4 were investigated with the density functional theory (DFT) method to understand the photoluminescence behaviors.