Synthesis, structure and fluorescence of a novel three-dimensional inorganic–organic hybrid polymer constructed from trimetallic clusters and mixed carboxylate ligands

Abstract

A new inorganic–organic hybrid framework coordination polymer, Cd 3(BDC) 0.5(BTC) 2(DMF)(H 2O)·3DMF·H 3O·H 2O 1, in which two carboxylate ligands, 1,4-benzenedicarboxylic acid (H 2BDC) and 1,3,5-benzenetricarboxylic acid (H 3BTC), coordinate with cadmium ions, has been synthesized under mild conditions and its structure solved by single-crystal X-ray diffraction (XRD) analysis. Polymer 1 crystallizes in the monoclinic system, space group P2 1/ c (No. 14) with a=15.750(3) Å, b=14.501(3) Å, c=19.363(4) Å, β=113.67(3)°, V=4050.4(14) Å 3, Z=4, R1=0.0374 and w R2=0.1148. Its structure revealed that the nine vertices of the secondary building units are linked by benzene rings from both H 3BTC and H 2BDC ligands to form a 3D network with 10×10 Å channels along [001] direction. Complex 1 is characterized by inductively coupled plasma analysis, powder XRD, infrared spectroscopy and thermogravimetric analysis. Polymer 1 exhibits intense fluorescence at 358 and 377 nm with λ excitation=208 nm in the solid state at room temperature.