An Amine Functionalized Metal-Organic Framework as an Effective Catalyst for Conversion of CO₂ and Biginelli...

A highly porous and thermally stable anionic Zn(II)-framework, {[(CH₃)₂NH₂⁺]₂[Zn₃((μ₃-O))(L)₂(H₂O)]·4DMF·2H₂O}_n (1), having exposed metal sites and pendant amine groups has been synthesized adopting the solvothermal technique. This anionic 3D framework showed two-fold interpenetration with 45.1% void volume. It has a 3,6-c binodal net with rare sit 3,6-conn topology. The metal bound aqua ligand could be easily removed along with the guest molecules in the lattice upon activation to afford the desolvated framework 1'. This produced exposed metal sites that, along with the pendant amine groups incorporated in the ligand, generated a coordination space in the framework to make it an outstanding heterogeneous catalyst for the chemical fixation of CO₂ with various epoxides under atmospheric pressure and in the three-component Biginelli reaction with different aldehydes, ethyl acetoacetate, and urea to afford dihydropyrimidinones.