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Omar M. Yaghi
Department of Chemistry & Biochemistry, UCLA


PhD, University of Illinois-Urbana; NSF Postdoctoral Fellow, Harvard University



The design and construction of chemical structures is at the heart of what chemist do, however, it remains more of an art than a science. This is largely due to the difficulty in predicting the outcome of chemical synthesis in particular those of large molecules and extended structures. To accomplish the synthesis of structures by design, it is important (1) to control the orientation (connectivity and geometry) of the building blocks in a targeted structure, and (2) to obtain the products in crystalline form so that their atomic arrangement can be definitively characterized by X-ray diffraction techniques. Indeed, the challenges are conceptual and practical in that one needs to know what structures might form from a given set of molecular building blocks and then find means of linking such building blocks into specific predetermined structures.

My research group has been developing the conceptual as well as the practical aspects of constructing chemical structures using the concept of molecular building blocks. Our research has led to the invention of new classes of crystalline porous materials most notably ones that we call metal-organic frameworks (MOFs). In general, MOF structures have two main components: the organic linkers and the metal oxide units. The linkers act as ‘struts’ that bridge the metal oxide units which in turn act as ‘joints’ in the resulting MOF architecture. This arrangement inevitability produces porous structures for which we’ve shown that molecules can pass through the pores with preservation of the MOF structure. Since we reported the first porous MOFs in 1998 and 1999, over 2,000 three-dimensional structures have been reported by my group and others around the world. It is worth noting that to date there are more porous MOFs than porous zeolites or carbon materials, and MOFs have extraordinary surface areas (2,000-6,500) exceeding those of state-of-art materials. Furthermore, MOFs are stable in air at room temperature and withstand temperatures up to 450°C. They are made using simple, inexpensive and high yielding solution synthesis methods.

These properties coupled with the flexibility with which one can vary the composition and metrics of the metal oxide units and the organic links of a given structure, have led to extensive investigation of MOFs in both academia and industry. At the heart of the matter is that we’ve shown for the first time that chemists are able to predictably assemble molecular building blocks into predetermined structures which can be functionalized and their metrics altered at will. We call this new kind of chemistry ‘reticular chemistry’ to emphasize that the dream of designing large and extended structure is becoming a reality. We define reticular chemistry as the chemistry dealing with linking of molecular building blocks, by strong bonds, into predetermined structures.

It is worth discussing aspects of reticular chemistry here to point out the thinking involved in the design of new structures. In recent contributions we reported how the concept of secondary building units (SBUs) is being applied with eminent success to the design of highly porous and rigid MOF structures. Here, clusters such as those of the copper-carboxylate paddlewheel, Cu2(O2C-)4, and the octahedral basic zinc carboxylate, Zn4O(O2C-)6, have been used as rigid SBUs that respectively act as square and octahedral joints (i.e. vertices) in the framework. If the designer identifies the one step reaction conditions that reproducibly lead to such a particular SBU, then control of the vertex geometry in the resulting MOF is possible. Since the organic links remain intact and their geometry preserved throughout the assembly process, one should also be able to predict the underlying topology of the resulting MOF structure.

However, the number of topologies that could, in principle, result from linking molecular shapes into extended MOF structures is vast—giving rise to three questions which my group is actively engaged in addressing: (1) From this large topology space, how do we as designers identify the most important topologies that should be considered in this chemistry? (2) How are they distributed among crystal structures already reported in the chemical literature? (3) How can these data be interpreted, organized, and classified for the purpose of developing systems of ‘grammar’ and ‘taxonomy’ that can lead to the design and construction of extended structures, the rationalization of existing structures, and the prediction of new ones?

Our ability to design and synthesize a MOF structure nearly at will is being used to provide solutions to problems of energy storage (hydrogen and methane), carbon dioxide sequestration, separation of gases for medical uses, polymerization catalysis, highly selective and sensitive sensors, and countless others currently under investigation by my group and by chemical, automobile and electronic industries. We work closely with companies; an aspect that provides my group members (undergraduates and doctorate graduate students, postdoctoral fellows, and research fellows) with a unique experience of being engaged in a spectrum of projects involving basic science of design and synthesis, characterization of structure and porosity, and the feasibility of MOFs in various applications.

The excitement of reticular chemistry and the ability to construct chemical structures from molecular building blocks has recently led us to create new classes of materials potentially as extensive as MOFs: metal-organic polyhedra (MOPs), zeolite imidazolate frameworks (ZIFs) and covalent organic frameworks (COFs). On a fundamental level, these classes of materials are produced by linking molecular building blocks through progressively stronger and stronger bonds, and doing so and still overcoming the ‘crystallization problem’. What kind of new chemistry and basic science concepts will these new materials inspire? What kind of new properties will be uncovered? What kind of new applications will be developed? And what immense pleasure will be derived in addressing these questions…

A partial list of ongoing projects in the Yaghi research group is provided here.

  • Design and Synthesis, structure characterization and porosity of MOFs, MOPs, ZIFs, and COFs
  • Automated and High throughput methods for inorganic synthesis and for X-ray powder diffraction studies of porous crystals
  • Design and synthesis of electronically conducting porous frameworks for highly selective and sensitive sensing
  • Gas storage and transport: Hydrogen storage for automobile fueling and mobile electronics; methane storage for automobile fueling and for transport of natural gas reserves; carbon dioxide separation and storage applications: power plants and automobile emissions; fuel cell applications including the separation of CO
  • Polymerization catalysis by MOFs for the production of polymers used as construction materials
  • Biomedical applications including drug molecule storage separation, storage and release by MOFs

Learn more about Prof. Yaghi in recent interviews published on the web:



Metal-Organic Frameworks

A Covalent Organic Framework

  • Robert W. Parry Collegiate Chair, University of Michigan
  • Sacconi Medal, Italian Chemical Society, Division of Inorganic Chemistry
  • Ranked among the top most-highly cited chemists (over 100 citations per paper)
  • Department of Chemistry Chair's Excellence in Research Award, University of Michigan
  • 3M Faculty Award
  • Graduate College Mentor Award
  • Exxon Award, American Chemical Society-Solid State Chem. Division
Recent Publications
  • Polymer-induced heteronucleation for the discovery of new extended solids, A. Grzesiak, F. Uribe, N. Ockwig, O. M. Yaghi, A. Matzger, Angew. Chem. Int. Ed., 2006, 118, 2615-2618.
  • A metal-organic framework with a hierarchical system of pores and tetrahedral building blocks, A. Sudik, A. Cote, A. Wong-Foy, M. O'Keeffe, O. M. Yaghi. Angew. Chem. Int. Ed., 2006, 118, 2590-2595.
  • A microporous metal-organic framework for gas-chomatographic separation of alkanes, B. Chen, C. Liang, J. Yang, O. M. Yaghi. Angew. Chem. Int. Ed., 2006, 118, 1390-1393.
  • Determination of the hydrogen absorption sites in Zn4O(1,4-benzenedicarboxylate) by single crystal neutron diffraction, E. Spencer, J. Howard, G. McIntyre, O. M. Yaghi Chem. Comm., 2006 (3),  278-280.
  • Effects of functionalization, catenation, and variation of the metal oxide and organic linking units on the low-pressure hydrogen adsorption properties of metal-organic frameworks, J. Roswell, O. M. Yaghi. J. Am. Chem. Soc., 2006, 128, 1304-1315.
  • Metal-organic frameworks with exceptionally high capacity for storage of carbon dioxide at room temperature, A. Millward, O. M. Yaghi. J. Am. Chem. Soc., 2006, 127, 17998-17999.
  • Characterization of H-2 binding sites in prototypical metal-organic frameworks by inelastic neutron scattering, J. Rowsell, J. Eckert, O. M. Yaghi. J. Am. Chem. Soc., 2006, 127, 14904-14910.
  • What do we know about three-periodic nets? O. Delgado-Friedrichs, M. D. Foster, M. O'Keeffe, D. M. Prosperio, M. Treacy, O. M. Yaghi, J. Solid State Chem., 2005, 178, 2533-2554.
  • Reticular chemistry - Present and future prospects - Introduction, M. O'Keeffe, O. M. Yaghi J. Solid State Chem., 2005, 178, V-VI.
  • Porous, crystalline, covalent organic frameworks, A. P. Cote, A. Benin, N. Ockwig, A. Matzger, M. O'Keeffe, O. M. Yaghi. Science, 2005, 310, 1166.
  • Porous Metal-Organic Truncated Octahedron Constructed from Paddle-Wheel Squares and Terthiophene Links, Z. Ni, A. Yasser, T. Antoun, O. M. Yaghi J. Am. Chem. Soc., 2005, 127, 12752.
  • Raman Spectra of Hydrogen and Deuterium Adsorbed on a Metal-Organic Framework, A. Centrone, D. Y. Siberio-Pérez, A. R. Millward, O. M. Yaghi, A. J. Matzger, G. Zerbi, Chem. Phys. Lett., 2005, 411, 516.
  • Gas Adsorption Sites in a Large-Pore Metal-Organic Framework, J.Rowsell, E. Spenser, J. Eckert, J.A. K. Howard, O. M. Yaghi. Science, 2005, 309, 1350.
  • Design, Synthesis, Structure, and Gas (N2, Ar, CO2, CH4 and H2) Sorption Properties of Porous Metal-Organic Tetrahedral and Heterocuboidal Polyhedra, A. Sudik, N. Ockwig, A. Millward, A. Cote, O. M. Yaghi, J. Am. Chem. Soc.. 2005, 127, 7110.
  • Metal-Organic Frameworks Based on Trigonal Prismatic Building Blocks and the New 'acs' Topology, A. Sudik, N. Ockwig, A. Cote, O. M. Yaghi, Inorg. Chem. 2005, 44, 2998.
  • High H2 Adsorption in a Microporous Metal-Organic Framework with Open-Metal Sites, B. Chen, D. S. Contreras, N. Ockwig, O. M. Yaghi, Angew.Chem. Int. Ed. 2005, 44, 4745. (Featured on cover)
  • Strategies for Hydrogen Storage in Metal-Organic Frameworks, J. Rowsell, O. M. Yaghi, Angew. Chem. Int. Ed. 2005, 44, 4670. (Featured on cover)
  • Reticular Chemistry: Occurrence and Taxonomy of Nets, and Grammar for the Design of Frameworks, N. Ockwig, O. D. Friedrichs, M. O'Keeffe, O. M. Yaghi, Acc. Chem. Res. 2005, 38, 176.
  • Transformation of a Metal-Organic Framework from the NbO to PtS Net, B. Chen, N. Ockwig, F. R. Fronczek, D. S. Contreras, O. M. Yaghi, Inorg. Chem., 2005, 44, 181.
  • Rod-Packings and Metal-Organic Frameworks Constructed from Rod-Shaped Secondary Building Units, N. Rosi, J. Kim, B. Chen, M. Eddaoudi, M. O'Keeffe, O. M. Yaghi. J. Am. Chem. Soc., 2005, 127, 1504.
  • Metal-Organic Frameworks: A New Class of Porous Materials, J. Rowsell, O. M. Yaghi, Micro- and Mesoporous Mater., 2004, 73, 3.

  • Structural Study of New Hydrocarbon Nano-Crystals by Energy-Filtered Electron Diffraction, J. Wu, N. Melcer, W. Sharp, M. O'Keeffe, JCH Spence, O. M. Yaghi, Ultramicroscopy, 2004, 98, p. 145.
  • Hydrogen Sorption in Functionalized Metal-Organic Frameworks, J. Rowsell, A. Millward, K. Park, O. M. Yaghi, J. Am. Chem. Soc. 2004, 126, p. 5666.
  • Design of New Materials for Methane Storage, T. Duren, L. Sarkisov, O. M. Yaghi, R. Q. Snurr, Langmuir, 2004, 20, 2683.
  • A Route to High Surface Area, Porosity and Inclusion of Large Molecules in Crystals, H. Chae, D. Y. Siberio-Perez, J. Kim, Y. Go, M. Eddaoudi, A. Matzger, M. O'Keeffe, O. M. Yaghi, Nature, 2004, 427, p. 523. (Featured in (1) Chemical & Engineering News magazine, Feb. 9, 2004, (2) BBC World Service, Feb. 04, (3) New Scientist, Feb. 04, and (4) several science magazines and localpapers)
  • Three-Periodic Nets and Tilings: Minimal Nets. C. Bonneau, O. D. Friedrichs, M. O'Keeffe, O. M. Yaghi, Acta Cryst., 2004, A60: p. 517.
  • Three-Periodic Nets and Tilings: Regular and Quasiregular Nets, O. D. Friedrichs, M. O'Keeffe, O. M. Yaghi, Acta Cryst., 2003, A59: p. 22.
  • Three-Periodic Nets and Tilings: Semiregular Nets, O. D. Friedrichs, M. O. O'Keeffe, O. M. Yaghi, Acta Cryst., 2003, A59: p. 515.
  • Reticular Synthesis and the Design of New Materials, O. M. Yaghi, M. O'Keeffe, N. Ockwig, H. K. Chae, M. Eddaoudi, J. Kim, Nature, 2003, 423, p.705.
  • Metal-Organic Frameworks as New Materials for Hydrogen Storage, N. Rosi, M. Eddaoudi, D. Vodak, J. Eckert, M. O'Keeffe, O. M. Yaghi, Science, 2003, 300, p. 1127. (Featured in (1) Chemical & Engineering News magazine, May 19, 2004, and (2) Technology Research News Magazine, May 21, 03)
  • Computation of Aromatic C3N4 Networks and Synthesis of the Molecular Precursor N(C3N3)3Cl6, D. T. Vodak, K. Kim, L. Iordanidis, P. Rasmussen, M. O'Keeffe, A. Matzger, O. M. Yaghi, Chem. Eur. J., 2003, 9, p. 4197.
  • The CdSO4, Rutile, Cooperate and Quartz Dual Nets: Interpenetration and Catenation, O. D. Friedrichs, M. O'Keeffe, O. M. Yaghi. Solid State Sciences, 2003, 5, p. 73.
  • Design of Frameworks with Mixed Triangular and Octahedral Building Blocks Exemplified by the Structure of [Zn4O(TCA)2] Having the Pyrite Topology, H. K. Chae, J. Kim, O. Delgado Friedrichs, M. O'Keeffe, O. M. Yaghi, Angew. Chem. Int. Ed., 2003, 42, p. 1819.
  • Cd16In64S13444: 35 Å Tetrahedron with a large Cavity, H. Li, J. Kim, O. M. Yaghi, Angew. Chem. Int. Ed., 2003, 42, p. 1819. (Featured on cover)
  • Synthesis and Characterization of Zirconogermanates, J. Plevert, R. S.-Smith, T. Gentz, H. Li, T. L. Groy, M. O'Keeffe, O. M. Yaghi, Inorg. Chem. 2003, 42, p. 5954.
  • Layered Structures Constructed from New Linkages of Ge7(O,OH,F)19 Clusters, J. Plevert, T. Gentz, T. L. Groy, M. O'Keeffe, O. M. Yaghi, Chem. Mater. 2003, 15, p. 714.

Complete List of Publications is availabe on the Yaghi Group Web Site.

Contact Info

Department of Chemistry & Biochemistry
Box 951569 (post)
607 Charles E. Young Drive East (courier)
Los Angeles, CA 90095-1569

Phone: (310) 206-0398
Fax: (310) 206-5891
Email: yaghi@chem.ucla.edu


Yaghi Group Web Site

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