Controlling chemistry with cations: Photochemistry within zeolites

V. Ramamurthy, J. Shailaja, Lakshmi S. Kaanumalle, R. B. Sunoj, J. Chandrasekhar

Research output: Contribution to journalArticle

35 Scopus citations

Abstract

The alkali ions present in the supercages of zeolites X and Y interact with included guest molecules through quadrupolar (cation-π), and dipolar (cation-carbonyl) interactions. The presence of such interactions can be inferred through solid-state NMR spectra of the guest molecules. Alkali ions, as illustrated in this article, can be exploited to control the photochemical and photophysical behaviors of the guest molecules. For example, molecules that rarely phosphoresce can be induced to do so within heavy cation-exchanged zeolites. The nature (electronic configuration) of the lowest triplet state of carbonyl compounds can be altered with the help of light alkali metal ions. This state switch (nπ*-ππ*) helps to bring out reactivity that normally remains dormant. Selectivity obtained during the singlet oxygen oxidation of olefins within zeolites illustrates the remarkable control that can be exerted on photoreactions with the help of a confined medium that also has active sites. The reaction cavities of zeolites, like enzymes, are not only well-defined and confined, but also have active sites that closely guide the reactant molecule from start to finish. The examples provided here illustrate that zeolites are far more useful than simple shape-selective catalysts.

Original languageEnglish (US)
Pages (from-to)1987-1999
Number of pages13
JournalChemical Communications
Volume3
Issue number16
DOIs
StatePublished - Jan 1 2003

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ASJC Scopus subject areas

  • Catalysis
  • Electronic, Optical and Magnetic Materials
  • Ceramics and Composites
  • Chemistry(all)
  • Surfaces, Coatings and Films
  • Metals and Alloys
  • Materials Chemistry

Cite this

Ramamurthy, V., Shailaja, J., Kaanumalle, L. S., Sunoj, R. B., & Chandrasekhar, J. (2003). Controlling chemistry with cations: Photochemistry within zeolites. Chemical Communications, 3(16), 1987-1999. https://doi.org/10.1039/b212741e