Highly Efficient Fixation of Carbon Dioxide at RT and Atmospheric Pressure Conditions: Influence of Polar Functionality on Selective Capture and Conversion of CO.

The rapid increase in the concentration of atmospheric carbon dioxide (CO) has resulted in undesirable environmental issues. Hence, selective CO capture and utilization as C1 feedstock for the preparation of high-value chemicals and fuels has been considered as a promising step toward mitigating the growing concentration of atmospheric CO. In this direction, herein we report rational construction of a Ag(I)-anchored sulfonate-functionalized UiO-66 MOF named as MOF-SOAg composed of CO-philic sulfonate functionality and catalytically active alkynophilic Ag(I) sites for chemical fixation of carbon dioxide. The MOF-SOAg exhibits selective as well as recyclable adsorption of CO with a high heat of adsorption energy () of 37.8 kJ/mol. On the other hand, the analogous MOF, UiO-66 doped with Ag(I), showed a lower value of 30 kJ/mol, highlighting the importance of the sulfonate group for stronger interaction with CO. Furthermore, the MOF-SOAg acts as an efficient heterogeneous catalyst for cyclic carboxylation of propargylic alcohols to generate α-alkylidene cyclic carbonates in >99% yield at mild conditions of RT and 1 bar CO. More importantly, one-pot synthesis of oxazolidinones by a three-component reaction between CO, propargylic alcohol, and primary amine has also been achieved using MOF-SOAg catalyst under the mild conditions. The MOF is highly recyclable and retains its superior catalytic activity even after several cycles. To the best of our knowledge, MOF-SOAg is the first example of MOF reported for RT chemical fixation of CO to oxazolidinones by aminolysis of α-alkylidene cyclic carbonates under the environment-friendly mild conditions.