4-[5-(Dicyanomethanido)thien-2-yl]-N-(n-hexadecyl)pyridinium (C16H33-PDCNT), 1, and 1-[N-(n-hexadecyl-4-pyridinio)]-2-[5-(dicyanomethanido)thien-2-yl]ethene (C16H33-PDCNTE), 2, belong to a class of push−pull zwitterionic molecules that strongly absorb in the visible region. These compounds possess a negatively charged dicyanomethanide group as a donor and an N-alkylpyridinium cation as an acceptor. These molecules are highly solvatochromic and very active for second-order nonlinear optical effects. A very interesting feature of these compounds is their aggregational behavior: in fact, both molecules examined in this work show sharp UV−vis absorption bands in different types of films obtained with the Langmuir−Blodgett (LB) technique. The aim of this work is to study the structural characteristics of LB films of compounds 1 and 2: in particular, a study of the sharp absorption peaks, due to aggregated forms, is important because these bands are photobleachable and can have interesting applications in the field of optical data storage.
Aggregated structures in Langmuir-Blodgett films of pyridinium-dicyanomethanide dyes
GRANDO, DANIELA;
1997-01-01
Abstract
4-[5-(Dicyanomethanido)thien-2-yl]-N-(n-hexadecyl)pyridinium (C16H33-PDCNT), 1, and 1-[N-(n-hexadecyl-4-pyridinio)]-2-[5-(dicyanomethanido)thien-2-yl]ethene (C16H33-PDCNTE), 2, belong to a class of push−pull zwitterionic molecules that strongly absorb in the visible region. These compounds possess a negatively charged dicyanomethanide group as a donor and an N-alkylpyridinium cation as an acceptor. These molecules are highly solvatochromic and very active for second-order nonlinear optical effects. A very interesting feature of these compounds is their aggregational behavior: in fact, both molecules examined in this work show sharp UV−vis absorption bands in different types of films obtained with the Langmuir−Blodgett (LB) technique. The aim of this work is to study the structural characteristics of LB films of compounds 1 and 2: in particular, a study of the sharp absorption peaks, due to aggregated forms, is important because these bands are photobleachable and can have interesting applications in the field of optical data storage.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
