Two coordination polymers constructed from a multidentate carboxylic acid ligand with a tertiary amine serve as acid–base catalysts for the synthesis of chloropropene carbonate from CO2 under atmospheric pressure

Abstract

Two new coordination polymers, [Ni(H₂O)(Hpdcd)(H₂O)₂]·DMF (1) and [Co(H₂O)(Hpdcd)(H₂O)₂]·DMF (2) (H₃pdcd = 1-(4-carboxyphenyl)-2,5-dimethyl, 1H-pyrrole-3,4-dicarboxylic acid), which were designed based on a tertiary amine ligand, were synthesized and characterized using multiple spectroscopy techniques, including single-crystal X-ray diffraction. These two 1D linear chains possess the properties of both a Lewis acid and organic base, which was confirmed by temperature programmed desorption of ammonia and on-line mass spectrometry (NH₃-TPD-MS), and selective sorption for carbon dioxide. Due to their acid–base properties, the compounds exhibited high catalytic activity, in the absence of co-catalysts, for solvent-free synthesis of chloropropene carbonate from CO₂ and epichlorohydrin under atmospheric CO₂ pressure. The yields of chloropropene carbonate were 88% and 87% for 1 and 2, respectively, under the optimized conditions.