In the quiet hum of a laboratory in Kyoto, a crystalline powder drinks water from the desert night. In a factory in Alberta, another porous material silently scrubs carbon dioxide from smokestack emissions. In a hospital in Berlin, a third delivers cancer drugs directly to tumours, sparing healthy tissue.
These are not miracles. They are metal–organic frameworks (MOFs)—engineered materials so revolutionary that the Royal Swedish Academy of Sciences has awarded the 2025 Nobel Prize in Chemistry to the three scientists who conceived and brought them to life: Susumu Kitagawa of Japan, Richard Robson of Australia, and Omar M. Yaghi of the United States.
Together, they did more than discover a new class of compounds. They invented a new language of molecular architecture—one in which chemists no longer just mix chemicals and hope for the best, but design matter from the atom up, like master builders drafting blueprints for invisible cities.
The birth of an idea: From wooden balls to molecular blueprints
It began with a teaching aid. In 1974, Richard Robson, a young lecturer at the University of Melbourne, was preparing molecular models for his students—wooden spheres drilled with holes at precise angles to mimic how atoms bond. As he assembled a diamond-like structure, he had a flash of insight: The geometry of the connections dictates the final form.
What if, instead of building random compounds, chemists could use the natural “directionality” of metal ions and organic linkers to self-assemble into predictable, open frameworks?
For over a decade, the idea simmered. Then, in 1989, Robson published a landmark paper describing a crystalline network made by linking copper ions with a four-armed organic molecule. The result wasn’t a dense solid—it was a scaffold riddled with cavities, like a molecular honeycomb.
Critics called it a curiosity. The structure was fragile, unstable when dried, and seemingly useless. But Robson had planted a seed: porous materials could be rationally designed. He had shown that chemistry could move beyond trial and error into the realm of architectural intention.
Kitagawa: Breathing life into crystals
In Japan, Susumu Kitagawa was listening. Trained as a physical chemist and inspired by the ancient Chinese philosopher Zhuangzi—who taught that “the useless may yet be useful”—Kitagawa refused to dismiss porous materials just because they lacked immediate application.
His early MOFs were two-dimensional and unstable. Funding agencies rejected his proposals. But he persisted.
Then, in 1997, everything changed. Using zinc or cobalt ions linked by 4,4’-bipyridine, Kitagawa created the first robust, three-dimensional MOF that retained its structure even after being emptied of solvent. More astonishingly, it could reversibly absorb gases—methane, nitrogen, oxygen—without collapsing.
But his true breakthrough came in 1998, when he proposed something radical: MOFs could be flexible. Unlike rigid zeolites (traditional porous materials made of silica), MOFs could breathe. One of his frameworks expanded when it absorbed methane, then shrank back when emptied—behaving like a lung.
This “softness” was revolutionary. It meant MOFs could respond dynamically to their environment—opening pores when needed, closing them when not. Kitagawa had given MOFs not just structure, but functionality and responsiveness.
Yaghi: Engineering the material of the future
Half a world away, Omar Yaghi was dreaming bigger. Born in a one-room home in Amman, Jordan, with no electricity, he found refuge in books. At ten, a clandestine visit to a locked school library introduced him to molecular diagrams – “beautiful, mysterious shapes that governed the world,” he later recalled.
After moving to the US at 15, he pursued chemistry with a singular goal: control. Traditional synthesis, he felt, was too chaotic – like throwing ingredients in a pot and hoping for a cake. He wanted Lego-like precision.
In 1995, at Arizona State University, Yaghi built the first two-dimensional MOF nets using copper and cobalt. One remained stable at 350°C—unheard of for organic-inorganic hybrids. He coined the term “metal–organic framework”, giving the field its identity.
Then came MOF-5 in 1999—a cubic lattice of zinc and terephthalic acid so porous that a single gram offered 3,000 square metres of surface area—roughly half a football pitch. It could store vast amounts of hydrogen or methane, offering a path to clean energy.
But Yaghi didn’t stop there. By 2003, he had created 16 variants of MOF-5, tuning pore size and chemistry for specific tasks. One stored enough methane to power a car; another captured carbon dioxide with unprecedented efficiency.
His most poetic achievement? Water from air. In the Arizona desert, his team deployed MOF-303, which pulls water vapour from air at night and releases it as liquid when warmed by the morning sun—producing 1.3 litres per kilogram of material per day, even in 20% humidity. For arid regions, this isn’t just innovation—it’s salvation.
MOFs in action: Solving 21st-century crises
Today, MOFs are moving from labs to real-world impact:
Clean Water: UiO-67 removes PFAS “forever chemicals” from drinking water. MIL-101 breaks down antibiotics in polluted rivers.
Climate Action: CALF-20, now being tested in a Canadian cement plant, captures CO₂ more efficiently than any known material.
Clean Energy: NU-1501 stores hydrogen at ambient pressure—eliminating the need for explosive high-pressure tanks in fuel-cell vehicles.
Healthcare: MOFs deliver drugs precisely to cancer cells, reduce side effects, and even act as biosensors.
Agriculture & Food: MOFs trap ethylene gas, slowing fruit ripening and reducing food waste.
Industry: They safely contain toxic gases used in semiconductor manufacturing and recover rare-earth metals from electronic waste.
Over 100,000 distinct MOFs have now been synthesised. With AI-driven design, researchers can now predict and build MOFs for almost any molecular task.
A new chapter in chemistry
Before Kitagawa, Robson, and Yaghi, porous materials were discovered by accident. Now, they are designed on purpose. The trio transformed chemistry from a craft into an engineering discipline—where molecules are not just studied, but commissioned.
As the Nobel Committee noted, their work embodies Alfred Nobel’s mandate: “the greatest benefit to humankind.” In an age of climate crisis, water scarcity, and energy transition, MOFs offer not just hope, but tools.
“They didn’t just find new molecules,” said one committee member. “They gave chemists new rooms to work in—rooms where we can trap pollution, harvest water, store energy, and heal the body.”
In building these invisible architectures, Kitagawa, Robson, and Yaghi have done something rare: they’ve expanded the very definition of what matter can do. And in doing so, they’ve helped build a more sustainable, equitable, and ingenious future—one molecular chamber at a time.