UNIGE document Scientific Article
previous document  unige:37939  next document
add to browser collection
Title

Excited-State Dynamics of Rhodamine 6G in Aqueous Solution and at the Dodecane/Water Interface

Authors
Published in Journal of Physical Chemistry. B, Condensed Matter, Materials, Surfaces, Interfaces and Biophysical. 2014, vol. 118, no. 19, p. 5184-5193
Abstract The excited-state dynamics of rhodamine 6G (R6G) has been investigated in aqueous solution using ultrafast transient absorption spectroscopy and at the dodecane/water interface using the femtosecond time-resolved surface second harmonic generation (SSHG) technique. As the R6G concentration exceeds ca. 1 mM in bulk water, both R6G monomers and aggregates are excited to a different extent when using pump pulses at 500 and 530 nm. The excited-state lifetime of the monomers is shortened compared to dilute solutions because of the occurrence of excitation energy transfer to the aggregates, which themselves decay nonradiatively to the ground state with a ca. 70 ps time constant. At the dodecane/water interface, both monomers and aggregates contribute to the SSHG signal to an extent that depends on the bulk concentration, the pump and probe wavelengths, and the polarization of probe and signal beams. The excited-state lifetime of the monomers at the interface is of the order of a few picoseconds even at bulk concentrations where it is as large as several nanoseconds. This is explained by the relatively high interfacial affinity of R6G that leads to a large interfacial concentration, favoring aggregation and thus rapid excitation energy transfer from monomers to aggregates.
Identifiers
Full text
Article (Published version) (1.5 MB) - document accessible for UNIGE members only Limited access to UNIGE
Other version: http://pubs.acs.org/doi/abs/10.1021/jp502058e
Structures
Research group Groupe Vauthey
Citation
(ISO format)
FEDOSEEVA, Marina, LETRUN, Romain, VAUTHEY, Eric. Excited-State Dynamics of Rhodamine 6G in Aqueous Solution and at the Dodecane/Water Interface. In: Journal of Physical Chemistry. B, Condensed Matter, Materials, Surfaces, Interfaces and Biophysical, 2014, vol. 118, n° 19, p. 5184-5193. https://archive-ouverte.unige.ch/unige:37939

226 hits

0 download

Update

Deposited on : 2014-06-18

Export document
Format :
Citation style :