R. Ricceri et al., Langmuir-Blodgett films of pyridinium-dicyanomethanide dyes mixtures with photobleachable absorption bands, COLL SURF A, 150(1-3), 1999, pp. 289-296
Citations number
20
Categorie Soggetti
Physical Chemistry/Chemical Physics
Journal title
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
We report on Langmuir-Blodgett (LB) films characterization of 4-[5-dicyanom
ethanido)thien-2-yl]-N-(n-hexadecyl)pyridinium (C16H33-PDCNT), and 1-(N-(n-
hexadecy]-4-pyridinio)-2-[5-(dicyanomethanido)thien-2-yl]ethene (C16H33-PDC
NTE); LB films of the pure compounds and of the mixtures of the two compoun
ds were prepared at 291 K: UV-vis investigation revealed the presence of ph
otobleachable absorption bands, the ones at about 530 nm and 640 nm were du
e to charge transfer transitions of the monomer of C16H33-PDCNT and C16H33-
PDCNTE, respectively; the sharp, photobleachable ones shifted to shorter wa
velengths were due to H-aggregates of the two compounds. By changing the mo
lar ratios of the two compounds in the mixtures and in other cases by annea
ling the LB films, the absorption maxima of the sharp, photobleachable band
s due to H-aggregates could be tuned in the range 415-467 nm. These LB film
s are thus very promising in view of optical data storage applications. (C)
1999 Elsevier Science B.V. All rights reserved.