Urea metal-organic frameworks as effective and size-selective hydrogen-bond catalysts

John M. Roberts, Branden M. Fini, Amy A. Sarjeant, Omar K. Farha, Joseph T. Hupp, Karl A. Scheidt

Research output: Contribution to journalArticle

222 Citations (Scopus)

Abstract

A new urea-containing metal-organic framework (MOF) was synthesized to act as a heterogeneous catalyst. Ureas are well-known for self-recognition and aggregation behavior, resulting in loss of catalytic competency. The catalyst spatial isolation achievable in a porous MOF environment suggests a potentially general solution. The combination of a symmetrical urea tetracarboxylate strut, 4,4′-bipyridine, and Zn(NO 3) 2•6H 2O under solvothermal conditions afforded a new microporous MOF (NU-601). This material is indeed an effective hydrogen-bond-donor catalyst for Friedel-Crafts reactions between pyrroles and nitroalkenes, whereas a homogeneous urea is much less competent. The higher rates of reaction of small substrates relative to larger ones with NU-601 strongly suggest that catalysis primarily occurs within the pores of this new material rather than on its exterior. To the best of our knowledge, this approach is the first example of specific engineering of successful hydrogen-bonding catalysis into a MOF material.

Original languageEnglish
Pages (from-to)3334-3337
Number of pages4
JournalJournal of the American Chemical Society
Volume134
Issue number7
DOIs
Publication statusPublished - Feb 22 2012

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ASJC Scopus subject areas

  • Catalysis
  • Chemistry(all)
  • Biochemistry
  • Colloid and Surface Chemistry

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