Bifunctional Lanthanide-Based Coordination Polymers: Conversion of CO 2 and Highly Selective Luminescence Sensing for Acetylacetone.

A series of bifunctional Ln(III)-based coordination polymers (CPs) {Ln(L)(DMA) 2 (NO 3 )} n [Ln(III) = Eu ( 1 ), Gd ( 2 ), and Dy ( 3 ); organic ligand H 2 L = 2,2'-(1,3,5,7-tetrahydroxyoctahydro-4,8-ethanopyrrolo[3,4- f ]isoindole-2,6(1 H ,3 H )-diyl)diacetic acid)] have been successfully synthesized. CPs 1 - 3 are isostructural and constructed from the dimeric Ln 2 unit in which two adjacent Ln III ions are bridged by two μ 3 -carboxyl oxygens, and the Ln 2 dimeric unit is connected by two NO 3 - ions, four DMA molecules, and four completely protonated L 2- ligands forming a 2D layer structure. The magnetic research reveals that CP 2 shows a significant cryogenic magnetocaloric effect (-Δ S m = 22.9 J kg -1 K -1 ; T = 2.0 K and Δ H = 7.0 T), whereas CP 3 exhibits slow magnetic relaxation property under H dc = 0 Oe field. Additionally, the luminescence explorations revealed that CP 1 can act as a recyclable luminescent probe for pollutant acetylacetone among various small organic solvent molecules, and the corresponding detection limit is 10 -7 mol/L. More importantly, CP 1 also exhibits good catalytic performance in the cycloaddition reaction of CO 2 and epoxides or cyanamides under mild conditions. As far as we know, CP 1 represents the first bifunctional lanthanide homogeneous catalyst that can efficiently catalyze the reaction of cyanamides/epoxides with CO 2 simultaneously.