title: Low-temperature spectral dynamics of single TDI molecules in n-alkane matrixes.
abstract: We report on studies of the influence of the matrix on the spectral dynamics of the zero-phonon-line (ZPL) emission by means of single molecule spectroscopy at low temperature. The host-guest system combinations consist of terrylenediimide (TDI) molecules embedded in four n-alkane matrixes of hexane, heptane, pentadecane, and hexadecane. Excitations into the broad vibronic absorption band and spectrally dispersed detection allows us to monitor fluorescence of single TDI molecules as a function of time. In the case of long-chain n-alkanes (pentadecane and hexadecane), the ZPL line is quite stable, showing spectral jumps of moderate frequency of less than 10 cm(-1) with an average time between the jumps of 10 s. In a clear contrast, the spectral dynamics of TDI molecules embedded within the short-length n-alkane matrixes (heptane and hexane) feature much more frequent spectral jumps that occur on a broader energy scale. The results suggest that matrixes composed of short-chain molecules are more susceptible to translations and/or rotations, which influence the fluorescence of single guest chromophores.
authors.affiliation: Department of Chemistry and Biochemistry, Ludwig-Maximilian-University Munich, Munich, Germany. mackowski@fizyka.umk.pl
authors.forename: Sebastian
authors.initials: S
authors.lastname: Mackowski
authors.forename: Stephan
authors.initials: S
authors.lastname: Wörmke
authors.forename: Moritz
authors.initials: M
authors.lastname: Ehrl
authors.forename: Christoph
authors.initials: C
authors.lastname: Bräuchle