Aromatic Molecules in Restricted Geometries: Photophysics of Naphthalene Included in a Cyclodextrin Functionalized Layered Solid

Mohanambe, L and Vasudevan, S (2005) Aromatic Molecules in Restricted Geometries: Photophysics of Naphthalene Included in a Cyclodextrin Functionalized Layered Solid. In: Journal of Physical Chemistry B, 109 (47). pp. 22523-22529.

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Abstract

The galleries of an Mg-Al layered double hydroxide have been functionalized by intercalation of carboxymethyl, \beta -cyclodextrin cavities. The anchored cavities form a random array of identical-sized hydrophobic nanopockets arranged in a bilayer fashion in the interlamellar space of the layered solid. Naphthalene molecules have been included within these cavities by partitioning from a polar solvent. The fluorescence from the included naphthalene shows an unusual behaviorsthe excimer to monomer emission intensity decreases with increasing concentration of included naphthalene. This is shown to be a consequence of the absence of translational mobility of the naphthalene-cyclodextrin adduct in the functionalized solid. Two types of included naphthalene have been identified: a preformed excimer-like species characterized by the absence of rise time in decay measurements and a monomeric species that is incapable of excimer formation due to the absence of suitably located included naphthalenes in its proximity. The concentration of each species and the enthalpy for excimer formation have been determined from the temperature variation of fluorescence intensities.

Item Type:	Journal Article
Publication:	Journal of Physical Chemistry B
Publisher:	American Chemical Society
Additional Information:	The Copyright belongs to American Chemical Society.
Department/Centre:	Division of Chemical Sciences > Inorganic & Physical Chemistry
Date Deposited:	06 Jan 2006
Last Modified:	19 Sep 2010 04:22
URI:	http://eprints.iisc.ac.in/id/eprint/4871

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