Photophysics and photochemistry of squaraine dyes. 3. Excited-state properties and poly(4-vinylpyridine)-induced fluorescence enhancement of bis(2,4,6-trihydroxyphenyl)squaraine

Das, Suresh ; Kamat, Prashant V. ; De la Barre, B. ; Thomas, George K. ; Ajayaghosh, A. ; George, M. V. (1992) Photophysics and photochemistry of squaraine dyes. 3. Excited-state properties and poly(4-vinylpyridine)-induced fluorescence enhancement of bis(2,4,6-trihydroxyphenyl)squaraine Journal of Physical Chemistry, 96 (25). pp. 10327-10330. ISSN 0022-3654

Full text not available from this repository.

Official URL: http://pubs.acs.org/doi/abs/10.1021/j100204a042

Related URL: http://dx.doi.org/10.1021/j100204a042

Abstract

Bis(2,4,6-trihydroxyphenyl)squaraine (Sq) has been shown to exist in three distinct protonation equilibria (pKa, = 3.5,7.0, and 9.5) in methanol/water solutions. The spectral properties of these different ionic species have been studied, and it has been observed that only the singly deprotonated Sq- has a measurable fluorescence yield (Φ = 0.02 in methanol). Addition of poly(4-vinylpyridine) to methanolic solutions of Sq- brings about a red shift in the absorption band, which is accompanied by a substantial enhancement in the fluorescence yield. These effects have been attributed to specific hydrogen bonding interactions of the singly deprotonated Sq- with poly(4-vinylpyridine).

Item Type:Article
Source:Copyright of this article belongs to American Chemical Society.
ID Code:417
Deposited On:21 Sep 2010 04:50
Last Modified:11 May 2012 10:00

Repository Staff Only: item control page