Probing zeolites with organic molecules: Supercages of X and Y zeolites are superpolar
Supercages of Li{sup +}- and Na{sup +}-exchanged X and Y zeolites are much more polar than even water. The extent of polarity depends on the nature and the number of cations present within a supercage. The polarity of Li{sup +}- and Na{sup +}-exchanged X and Y zeolites decreases in the presence of water. In presence of water the contribution of cations toward polarity is much smaller than water itself. In this study polarity has been monitored with organic probe molecules, Nile red, pyrene 1-carboxaldehyde and coumarin-500. A connection between polarity and electric field within a cage has also been established. Since the supercages are much more polar than all organic solvents, they can be characterized as superpolar. Because of this one may be able to achieve excited-state switching of carbonyl compounds within a zeolite while such may not be possible in organic solvents. The n{pi}*-{pi}{pi}* state switching of acetophenones is easily achieved within a zeolite while such does not occur in polar solvent methanol-ethanol mixture.
- Research Organization:
- Tulane Univ., New Orleans, LA (US)
- OSTI ID:
- 20015188
- Journal Information:
- Langmuir, Vol. 16, Issue 1; Other Information: PBD: 11 Jan 2000; ISSN 0743-7463
- Country of Publication:
- United States
- Language:
- English
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