A flexible aromatic tetracarboxylate as a new linker for coordination polymers

Abstract

Two new cadmium(II)-based materials, featuring two-dimensional (2D) [Cd2(µ6-deta)(bpy)(H2O)]n (1) and three-dimensional (3D) [Cd2(µ5-deta)(bpy)2(H2O)]n (2) structures, were constructed by the hydrothermal method from 2,3′,4′,5-diphenyl ether tetracarboxylic acid (H4deta) as an unexplored linker in research on coordination polymers (CPs) and 2,2′-bipyridine (bpy) as a mediator of crystallization. Microcrystalline samples of 1 and 2 were analyzed by IR/PXRD/EA/TGA and X-ray diffraction using single crystals. Structures and topologies of CPs 1 and 2 were established, revealing a 4,6L45 topological layer in 1 and a 3,5T1 topological framework in 2. Structural differences for 1 and 2 are attributed to distinct molar ratios between Cd2+ and bpy during the hydrothermal synthesis. Luminescence and thermal behavior of the obtained materials were also investigated. The present work opens up the use of an unexplored 2,3′,4′,5-diphenyl ether tetracarboxylic acid as a versatile and flexible linker toward the generation of functional coordination polymer materials.