title: Unexpected photoluminescence of fluorinated naphthalene diimides.
abstract: Two new amino core-substituted naphthalene diimides (cNDIs) bearing fluorinated side chains have been synthesised. Steady-state and time-resolved fluorescence spectroscopy reveals unprecedented optical properties for the cNDIs with high quantum yields of ∼0.8 and fluorescence lifetimes of ∼13 ns in a range of solvents. These properties are apparent at the level of single molecules, where the compounds also show exceptional photostability under pulsed-laser excitation. Photon emission is remarkably consistent with very few long timescale (millisecond or longer) interruptions with molecules regularly undergoing >10(7) cycles of excitation and emission. Intermittencies owing to triplet-state formation occur on a sub-millisecond timescale with a low yield of 1-2%, indicating that the presence of the fluorine atoms does not lead to a significant triplet yield through the heavy-atom effect. These properties make the compounds excellent candidates for single-molecule labelling applications.
authors: School of Chemistry, Monash University, Wellington Rd, Clayton 3800, Victoria (Australia), Fax: (+613) 9905 4597.
authors: Subashani
authors: S
authors: Maniam
authors: Rosalind P
authors: RP
authors: Cox
authors: Steven J
authors: SJ
authors: Langford
authors: Toby D M
authors: TD
authors: Bell
keywords: fluorescence quantum yield; naphthalene diimide; photostability; single-molecule studies; time-resolved spectroscopy