Reorganization of perylene bisimide J-aggregates: from delocalized collective to localized individual excitations.

Summary, in English

Water-induced reorganization of individual one-dimensional J-aggregates of perylene bisimide (PBI) dyes was observed by fluorescence microscopy. Fluorescence spectra and decay kinetics of individual J-aggregates immobilized on glass surfaces were measured under a dry nitrogen atmosphere and under humid conditions. The fluorescence properties of PBI J-aggregates arisen from collective excitons under dry nitrogen atmosphere were changed to those of non-interacting dye monomers when water vapor was introduced into the environment (sample chamber). Time-dependent changes of the fluorescence spectra and lifetimes upon exposure to water vapor suggest an initial coordination of water molecules at defect sites leading to the formation of H-type dimer units that act as exciton quenchers, and a subsequent slower disintegration of the hydrogen-bonded J-aggregate into monomers that lack resonance coupling. Our present studies resulted in a direct demonstration of how drastically the optical properties of molecular ensembles and characteristics of their excited states can be changed by delicate reorganization of dye molecules at nanometre scales.

• Author: Yuxi Tian; Vladimir Stepanenko; Theo E Kaiser; Frank Würthner; Ivan Scheblykin
• Department/s: Chemical Physics
• Publishing year: 2012
• Language: English
• Pages: 218-223
• Publication/Series: Nanoscale
• Volume: 4
• Issue: 1
• Links: http://dx.doi.org/10.1039/c1nr10973a
• Document type: Journal article
• Publisher: Royal Society of Chemistry
• Topic: Nano-technology
• Status: Published
• ISBN/ISSN/Other: ISSN: 2040-3372