Balancing Porosity and Binding Affinity in Vinyl‐Functionalized Zr‐Based Metal–Organic Frameworks for Gas Adsorption

Gas storage and capture in metal–organic frameworks (MOFs) are significantly influenced by the interplay between porosity and specific binding sites. In particular, a critical challenge in adsorbent design is the loss of porosity that often accompanies the incorporation of strong interaction sites. Herein, we demonstrate a systematic study on how a vinyl functional group embedded within organic struts with different lengths modulates gas–framework interactions. We investigate two isostructural Zr‐based MOFs, Zr‐CVB [Zr 6 O 4 (OH) 4 (CVB) 6 ] (H 2 CVB = 4‐(2‐carboxyvinyl)benzoic acid) and Zr‐CVN [Zr 6 O 4 (OH) 4 (CVN) 6 ] (H 2 CVN = ( E )‐6‐(2‐carboxyvinyl)‐2‐naphthoic acid), using UiO‐67 as a benchmark. The integration of the vinyl moiety in Zr‐CVN and Zr‐CVB clearly improved the isosteric heats of adsorption ( Q st ) for H 2 (9.4 kJ mol −1 for Zr‐CVN and 11.2 kJ mol −1 for Zr‐CVB) and CO 2 (24.8 kJ mol −1 for Zr‐CVN and 34.2 kJ mol −1 for Zr‐CVB), which are attributed to the H‐π and quadrupole‐π interactions, respectively. These Q st values represent the highest reported values among Zr‐based MOFs with comparable surface areas. This behavior deviates from the conventional trade‐off between surface area ( S BET ) and isosteric heats ( Q st ) observed in Zr‐based MOFs. These results establish a backbone‐embedded vinyl functionality as an effective structural design strategy for enhancing gas adsorption without compromising porosity.