Characterization of hemicyanine Langmuir-Blodgett films by picosecond time-resolved fluorescence

Emmanuel Abraham (1) , Christine Grauby-Heywang (1) , Sophia Selector (2) , Gediminas Jonusauskas (1)

1 CPMOH - Centre de physique moléculaire optique et hertzienne
2 A.N. Frumkin Institute of Physical Chemistry and Electrochemistry

Hemicyanine Langmuir–Blodgett films have been elaborated and characterized using stationary and time-resolved spectroscopic techniques. Depending on the experimental conditions, especially the pH of the water subphase, the absorption spectra of the films indicate the presence of non-fluorescent Haggregates in the monolayer. Time-resolved fluorescence measurements revealed three mono-exponential decay times: a very short one (20–23 ps) attributed to an excited intramolecular charge transfer state and two longer ones (100–120 ps and 400–590 ps) attributed to thephotoisomerization of the chromophores.

Mots clés: Langmuir–Blodgett film; Hemicyanine; Fluorescence; Charge transfer; Photoisomerization

Domaines: Optique [physics.optics]

Emmanuel Abraham, Christine Grauby-Heywang, Sophia Selector, Gediminas Jonusauskas. Characterization of hemicyanine Langmuir-Blodgett films by picosecond time-resolved fluorescence. Journal of Photochemistry and Photobiology B: Biology, 2008, 93 (1), pp.44-52. ⟨10.1016/j.photobiol.2008.04.003⟩. ⟨hal-00400200⟩