Dual emission from 4-dimethylaminobenzonitrile in cyclodextrin derivatives

Citation
Hs. Banu et al., Dual emission from 4-dimethylaminobenzonitrile in cyclodextrin derivatives, J PHOTOCH A, 131(1-3), 2000, pp. 101-110
Citations number
26
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physical Chemistry/Chemical Physics
Journal title
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
ISSN journal
1010-6030 → ACNP
Volume
131
Issue
1-3
Year of publication
2000
Pages
101 - 110
Database
ISI
SICI code
1010-6030(20000229)131:1-3<101:DEF4IC>2.0.ZU;2-R
Abstract
Dual fluorescence of 4-dimethylaminobenzonitrile (DMABN) in the presence of hydroxypropyl-beta-cyclodextrin (HP-beta-CD) and dimethyl-beta-cyclodextri n (DM-beta-CD) in aqueous media is reported. Equilibrium constants for the formation of inclusion complexes between DMABN and CD-derivatives are calcu lated for the ground as well as the excited states. Two maxima are observed in the excitation spectra, indicating the presence of two absorbing specie s. Fluorescence lifetimes of these complexes are also reported in addition to their ICD spectra. Based on the experimental observations, it is conclud ed that while the more polar TICT emission originates from the aqueous exte rior, LE emission occurs predominantly from the complexed molecule. Higher order complexes are not observed. Absence of hydrogen bonding and a 'tighte r fit' with the CD derivatives are the main factors responsible for this. ( C) 2000 Elsevier Science S.A. All rights reserved.