Synthesis and characterization of three 2D Cd (II) coordination polymers built with terphenyl-2, 2′, 4, 4′-tetracarboxylate and flexible bis(imidazole)

Abstract

Three new CdII coordination polymers, namely, {[Cd2 (L) (1, 2-bix)2(H2O)2]⋅2H2O}n(1), [Cd2 (L) (1, 3-bix)2]n (2), and {[Cd (H2L) (1, 4-bix) (H2O)2]⋅2H2O}n (3) [H4L=terphenyl-2, 2′, 4, 4′-tetracarboxylic acid, 1, n-bix=1, n-bis(imidazol-l-ylmethyl) benzene (n=2, 3, 4)], have been synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction, IR, thermogravimetric analysis, and fluorescent analysis. Complex 1 is a 2D wavelike network structure incorporating the dinuclear Cd2 (1, 2-bix)2 units, whereas complex 2 possesses a 2D stair-like network structure consisting of the dinuclear Cd2O2 units. Complex 3 features a 2D puckered network constructed by 1D [Cd (H2L)]n and 1D [Cd (1, 4-bix)]n chains. The results show that the structural diversity of the polymers is mainly attributed to the usage of diverse ancillary bis (imidazol-1-ylmethyl)-benzene isomers ligands. The thermal stabilities and photoluminescence behaviors were also investigated.