Fluorescence and two-photon absorption of push-pull aryl(bi)thiophenes: structure-property relationships.
Photophysical and TPA properties of series of push-pull aryl(bi)thiophene chromophores bearing electron-donating (D) and electron-withdrawing (A) end-groups of increasing strength are presented. All compounds show an intense intramolecular charge transfer (ICT) absorption band in the visible region. Increasing the D and/or A strength as well as the length of the conjugated path induces bathochromic and hyperchromic shifts of the absorption band as reported for analogous push-pull polyenes. Yet, in contrast with corresponding push-pull polyenes, a significant increase in fluorescence is observed. In particular, chromophores built from a phenyl-bithienyl conjugated path and bearing strong D and A end-groups were found to combine very large one and two-photon brightness as well as strong emission in the red/NIR region. These molecules hold promise as biphotonic fluorescent probes for bioimaging.
Univ. Bordeaux, ISM, UMR 5255 CNRS, F-33400 Talence, France.
Emilie
E
Genin
Vincent
V
Hugues
Guillaume
G
Clermont
Cyril
C
Herbivo
M Cidália R
MC
Castro
Alain
A
Comel
M Manuela M
MM
Raposo
Mireille
M
Blanchard-Desce