2025 Nobel Prize in Chemistry: Molecular Architecture in Solving Society's Problems

The 2025 Nobel Prize in Chemistry laureates were announced on October 8th: Susumu Kitagawa, Richard Robson, and Omar M. Yaghi shared the area's most prestigious award, recognized for their contributions to the development of metal-organic frameworks, also called MOFs.

These structures have broad applicability in chemistry, both on a laboratory and industrial scale, and can be used in the removal of pollutants from water and air, as catalysts in chemical reactions, and even in controlled drug delivery.

Coordination Compounds: At the Forefront of MOFs

To understand metal-organic frameworks, it is necessary to 'revisit' their precursors: coordination compounds. The coordination theory, proposed by Alfred Werner in 1893, was the first attempt to explain the bonds present in these systems, even before the discovery of the electron, which would be carried out in 1897 by J. J. Thomson.

In these compounds, the metallic center acts as a Lewis acid, receiving two electrons pairs, while the ligands are Lewis bases, donating them. A covalent bond is thus formed between the metal and each ligand. The final geometry depends mainly on the oxidation number and the electronic configuration of the metal, although the nature of the ligands can also favor certain spatial arrangements. Modern theories, such as Crystal Field Theory (CFT) and Ligand Field Theory (LFT), allow for a more complete description of these interactions.

Kitagawa, Robson, and Yaghi: A Victorious Cooperation

The trajectory of MOFs began in 1989, when R. Robson conducted the first experiments aimed at developing a methodology to build ordered networks from the interaction between metals and organic ligands, also called linkers, in these systems. The product obtained was a well-organized crystal, with cavities of controlled geometry and size. Robson recognized the potential of these structures, although the instability of the materials was still a challenge.

Between 1992 and 2003, Kitagawa and Yaghi worked separately on developing methodologies to stabilize these systems and explore their possible applications. Since then, thousands of MOFs have been synthesized, driving new knowledge and building strategies.

Molecular Architecture in MOF Synthesis

Metal-organic frameworks can be understood as a direct evolution of coordination compounds. In their synthesis, a metallic ion, or a previously prepared metallic cluster, is usually reacted with organic linkers. The spatial arrangement for the bonds generated between the metallic centers and the linkers allows for the three-dimensional growth of the network, going beyond the discrete coordinations typical of classical complexes.

Due to the complexity involved, the term 'molecular architecture' is frequently employed to describe the process of conception and structural planning of these materials. Small variations in the structure of the linkers can significantly alter the organization and properties of the MOF. The choice of the metal, in turn, is equally determining: the oxidation number, its size, and coordination geometry influence the three-dimensional structure, stability, and applicability of the generated compound.

The great interest in MOFs lies in the pores that form in their structures: cavities of adjustable dimensions and shapes during synthesis, capable of selectively trapping molecules of compatible sizes. Their applications stem precisely from such a structural element.

Applying MOFs to Environmental Problems

The ability to retain molecules in their pores gives metal-organic frameworks a wide range of applications. Pores of ideal size and geometry allows for high selectivity regarding the species that will be trapped.

Gas capture was one of the first successfully tested applications, with MOFs capable of filtering and removing carbon dioxide and other toxic industrial pollutants. At the same time, this property can be explored for the storage and transport of fuel gases, such as hydrogen and methane. Currently, these networks are already being used in research aimed at removing pollutants from the atmosphere and water bodies, acting as true 'selective filters' on a molecular scale.

In the biomedical field, MOFs have been highlighted in controlled drug release. Their internal cavities trap bioactive molecules and release them gradually when stimulated by external factors, such as changes in pH, temperature, or the presence of specific biomarkers. In this way, they act as intelligent carriers, capable of delivering the active substance to the right place and at the right time, increasing therapeutic efficiency.

Metal-organic frameworks can also act as heterogeneous catalysts. In this case, the pores function as active reaction sites, while the metallic centers can participate directly or indirectly in the catalytic process. The analogy with biological enzymes is the simplest: in them, metallic ions often act as essential cofactors, while amino acid residues modulate the active site environment, a function performed by the linkers.

Challenges and Future Perspectives for MOFs

Despite the enormous technological potential, some questions still challenge researchers: What is the real cost of large-scale production? What should be done with pollutants after their capture? How to increase the selectivity of MOFs in the face of complex mixtures?

The search for answers to these questions has gained new momentum. Areas honored with the Nobel Prize show exponential growth in scientific publications.

This advancement reinforces the importance of forming new curious and creative scientists, something stimulated by initiatives such as scientific olympiads and programs like Etapa SigmaCamp, which awaken interest in research and solving real problems.

For those who are not yet familiar, Etapa SigmaCamp is an immersive camp focused on the STEM area (Science, Technology, Engineering, and Mathematics) exclusively for Brazilian students. It offers contact with internationally renowned professionals with lectures, practical labs, and advanced classes.

Registrations for the next edition, which will take place in 2026, are already closed. But, you can follow the social media of Sistema Etapa and subscribe to our newsletter to receive the news about Etapa SigmaCamp 2027 in your email firsthand.