Synthesis and electronic properties of 1,2-hemisquarimines and their encapsulation in a cucurbit[7]uril host.
Chemistry
; 20(21): 6412-20, 2014 May 19.
Article
em En
| MEDLINE
| ID: mdl-24700672
ABSTRACT
The synthesis of a new class of robust squaraine dyes, colloquially named 1,2-hemisquarimines (1,2-HSQiMs), through the microwave-assisted condensation of aniline derivatives with the 1,2-squaraine core is reported. In CH3CN, 1,2-HSQiMs show a broad absorption band with a high extinction coefficient and a maximum at around λ=530â
nm, as well as an emission band centered at about λ=574â
nm, that are pH dependent. Protonation of the imine nitrogen causes a redshift of both absorption and emission maxima, with a concomitant increase in the lifetime of the emitting excited state. Encapsulation of the chromophore into a cucurbit[7]uril host revealed fluorescence enhancement and increased photostability in water. The redox characteristics of 1,2-HSQiMs indicate that charge injection into TiO2 is possible; this opens up promising perspectives for their use as photosensitizers for solar energy conversion.
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Base de dados:
MEDLINE
Idioma:
En
Revista:
Chemistry
Assunto da revista:
QUIMICA
Ano de publicação:
2014
Tipo de documento:
Article