Pyrene-Based Zinc-Organic Framework for Catalyzing Two Types of CO₂ Chemical Fixation

Developing efficient metal-organic frameworks (MOFs) for catalytic CO₂ transformation has attracted significant interest worldwide, as it is crucial for environmental sustainability and sustainable development. Herein, we present a two-dimensional (2D) MOF {[Zn(Tip)_0.5(nia^2-)]·H₂O}_n, namely, Zn-TN, based on 1, 3, 6, 8 - tetraimidazolyl-pyrene (Tip) and 5-(1,8-naphthalimido)-isophthalic acid (H₂nia). Zn-TN has a (4, 4)-connected {4·6⁴·8}₂{4²·6⁴} network and exhibits good thermal and solvent stability as well as a wide pH durability. In addition, Zn-TN can catalyze the fixation of CO₂ with propargylic amines to produce 2-oxazolidinones under mild conditions (60 °C, 1 atm of CO₂), and a gram-scale experiment has been successfully achieved. ¹H NMR data indicate that Zn-TN presents the capability of activating the acetylene bond of propargylic amine, together with 1, 4-diazabicyclo [2.2.2] octane (DABCO) to activate amine proton, which synergistically promotes the reaction. Besides, Zn-TN can promote CO₂ conversion with epoxides to produce cyclic carbonates under mild conditions (60 °C, 1 atm of CO₂) due to the activation of epoxides by Zn nodes in the framework. Notably, the catalyst Zn-TN can be reused five times in the two reactions mentioned above, demonstrating good reusability.