Metal–organic frameworks: defining new spaces for chemistry

<sec><p indent="0mm">The 2025 Nobel Prize in Chemistry has been awarded to Susumu Kitagawa from Kyoto University, Richard Robson from the University of Melbourne, and Omar M. Yaghi from the University of California, Berkeley, for the development of metal–organic frameworks (MOFs). The Nobel Committee for Chemistry emphasized that MOFs have enormous potential, bringing previously unforeseen opportunities for custom-made materials with new functions. The groundbreaking significance of MOFs centers on their definition of a unique “new space” in chemistry, which encompasses both the open physical space within their ordered structures and the paradigm-shifting platforms they have unlocked for scientific research. This space spanning structural and academic dimensions has established MOFs as a key engine for developments in chemistry, materials science, and related disciplines, earning them recognition with this year’s Nobel Prize in Chemistry. </sec><sec> As a central science, chemistry has long enabled precise molecular design, but extending atomic-level control to two- and three-dimensional extended structures remained a daunting challenge. Robson’s pioneering concept of predicting coordination network structures based on building units’ geometry laid the important groundwork, while Yaghi and Kitagawa shifted the field from “crystal engineering” to “framework chemistry”. MOFs with high stability, permanent porosity, and tunability were realized through the introduction of key concepts such as secondary building units, isoreticular design, and soft porous crystals. This View article traces the historical development of MOF chemistry, emphasizing key breakthroughs in the structural design and synthesis, adsorption measurements, functionalization, and flexibility and dynamics. </sec><sec> The article further examines the evolving trends in modern MOF synthesis research, distinguished by new topology theories (e.g., merged net, related net, derived net, and net-clipping) and hybrid linkage construction methods. The increasing diversification of building units has spurred exploration of anisotropic materials, interwoven materials, interlocked structures, and frameworks with sequences. Developments in techniques such as <italic>in-situ</italic> electron microscopy and electron crystallography have rendered structural characterization of MOFs more comprehensive and unambiguous, while their integration with artificial intelligence (AI) and machine learning has accelerated material prediction and synthesis. </sec><sec> Porous MOFs not only offer methods to control matter beyond the molecular level, but also provide highly open space for further manipulation, with accessibility, responsiveness, and adaptability as key research focuses. Leveraging ordered active sites on the framework backbones or in the pores, they serve as ideal catalytic centers with unparalleled precision and controllable microenvironments. Electrically conductive, proton-conductive, electrocatalytic, and photocatalytic frameworks have emerged. Additionally, studies exploring the distinct interfaces between MOFs and other chemical or biological entities have garnered substantial research interest. </sec><sec> Highlighting MOFs’ practical value, the article also discusses their role in addressing global challenges: their ultrahigh gas adsorption capacity and selectivity drive applications in carbon capture (including direct air capture), natural gas storage, and water harvesting. MOFs also show promise in pollutant removal, targeted drug delivery, and electronics, with commercialization advancing via leading companies and supported by global research initiatives. </sec><sec> Over a century since Gilbert Lewis’s seminal paper, <italic>The Atom and the Molecule</italic>, human mastery of microscale units has advanced from understanding atomic bonding to designing deliberate spatial architectures. Atoms are fixed in molecules with specific spatial arrangements; similarly, molecules are anchored in frameworks with distinct directional alignments and spatial configurations. Fittingly, the 2025 Nobel Prize in Chemistry honors the pioneering development of MOFs—the epitome of this spatial design philosophy—recognizing their transformative potential to address global challenges in clear energy, clean water, and carbon neutrality. </sec>