Resorcin[4]arene-Based Microporous Metal–Organic Framework as an Efficient Catalyst for CO₂ Cycloaddition with Epoxides and Highly Selective Luminescent Sensing of Cr₂O₇^2–

A stable microporous anionic metal–organic framework (MOF), [(CH 3 ) 2 NH 2 ] 6 [Cd 3 L(H 2 O) 2 ]·12H 2 O ( 1 ), has been synthesized via solvothermal assembly of a new resorcin[4]arene-functionalized dodecacarboxylic acid (H 12 L) and Cd(II) cations. The constructed MOF ( 1 ) was characterized by single-crystal X-ray diffraction and other physicochemical analyses. 1 exhibits a fascinating 3D microporous framework structure, in which the free water molecules and the [(CH 3 ) 2 NH 2 ] + cations were located. Remarkably, the exposed Lewis acid Cd(II) sites of activated 1 make it an efficient heterogeneous catalyst for the cycloaddition of CO 2 with epoxides at 1 and 20 atm. Importantly, the activated samples of 1 can be reused at least five circles with excellent catalytic performance. Moreover, the fluorescence detection of Cr 2 O 7 2– and Fe 3+ was studied by using 1 as a potential luminescent sensor.