Formation of a potassium coordination polymer based on a novel 2-sulfono-benzene-1,3,5-tricarboxylic acid: Synthesis, characterization, and application of the organocatalyst in CO2 cycloaddition reaction

Abstract

In the present work, a new 3D potassium coordination polymer (1) was prepared by oxidation of sulfonated mesitylene. Its novel sulfono-tricarboxylic ligand, 2-sulfono-benzene-1,3,5-tricarboxylic acid (2), which acted as a structure-directing building block, was successfully synthesized by ion exchange of the potassium coordination polymer (1). The 3D coordination polymer and the sulfonate-carboxylate ligand were characterized by FT-IR and 1H and 13C NMR spectroscopies, and their molecular structures were determined by single-crystal X-ray diffraction. In addition, thermal stability and adsorption/desorption behavior of 1 was investigated by TGA-DTA and N2 adsorption/desorption techniques, respectively. The catalytic activities of the ligand, as a novel and simple organocatalyst, and the rarely explored potassium CPs were studied in the CO2 cycloaddition reaction. The results showed 2 is an efficient organocatalyst in the CO2 cycloaddition process. It is suggested that the synergetic effect among Brønsted acid COOH, Lewis base I− and free water molecules facilitate this reaction.