Zeolite Imidazolate Frameworks
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A large segment of the global economy (US$350 billion) is based on the use of crystalline microporous zeolites in petrochemical cracking, ion-exchange for water softening and purification, and in the separation of gases. Zeolite structures are composed of tetrahedral Si(Al)O4 units covalently joined by bridging O atoms to produce over 150 different types of framework. A long-standing challenge is to incorporate transition metal ions and organic units within their pores and, more desirably, to do so as an integral part of the zeolite framework. This would be useful in many catalytic applications as the pores would be lined with a high concentration of ordered transition metal sites whose electronic and steric properties can be tailored by functionalization of the organic links. However, the vision of achieving such a zeolite that combines these features remains largely unrealized. We outline a general synthesis of structures having zeolite framework topologies in which all tetrahedral atoms are transition metals and all bridging ones are imidazolate units.
Recent Leading Publications:
Zeolite A Imidazolate Frameworks, Hayashi, H.; Côté, A.P.; Furukawa,
H.; O'Keeffe, M.; Yaghi, O.M., Nature Materials, advance online publication,
27 May 2007, doi:10.1038/nmat1927.
Exceptional chemical and thermal stability of zeolitic imidazolate frameworks,
K. S. Park, A. P. Côté, J. Y. Choi, R. Huang, F. J. Uribe-Romo,
H. K. Chae, M. O'Keeffe, O. M. Yaghi, Proc. Nat. Acad. Sci. USA, 2006,
103, 10186-10191.
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