An optical single-molecule study is reported of a quickly frozen solution of 2.3,8.9-dibenzanthanthrene (DBATT) in n-tetradecane at 1.4 K. The orientation has been measured of several hundreds of... Show moreAn optical single-molecule study is reported of a quickly frozen solution of 2.3,8.9-dibenzanthanthrene (DBATT) in n-tetradecane at 1.4 K. The orientation has been measured of several hundreds of DBATT molecules within a confocal detection volume of similar to 10 mum(3) as a function of their resonance frequency in the range of the two 0-0 bands in the fluorescence-excitation spectrum. Each band is found to correspond to a distinct distribution of orientations of DBATT molecules. A particular resonance frequency within a band is not correlated with a specific molecular orientation. (C) 2001 Elsevier Science B.V. All rights reserved. Show less
The spectral stability of three guest molecules embedded in a quickly frozen n-tetradecane matrix has been investigated on a single-molecular level at liquid-helium temperature. In total, about... Show moreThe spectral stability of three guest molecules embedded in a quickly frozen n-tetradecane matrix has been investigated on a single-molecular level at liquid-helium temperature. In total, about 2500 spectral trajectories of 476 terrylene molecules, 328 dibenzanthanthrene molecules, and 252 pentacene molecules were recorded. Both line broadening and spectral jumps are analyzed and the latter are found to be mainly light induced. The spectral changes in essence reflect the dynamics of the host matrix and the differences between the guest molecules may be reduced to differences in their pumping cycles. (C) 2001 American Institute of Physics. Show less
Bloess, A.; Durand, Y.; Matsushita, M.; Verberk, R.; Groenen, E.J.J.; Schmidt, J. 2001
A study is presented of the orientation of single 2.3, 8.9-dibenzanthanthrene molecules in n-tetradecane as a function of their spatial position on a length scale of 2 mm down to a few hundreds of... Show moreA study is presented of the orientation of single 2.3, 8.9-dibenzanthanthrene molecules in n-tetradecane as a function of their spatial position on a length scale of 2 mm down to a few hundreds of nanometers at 1.4 K, which allows us to obtain structural information about this host/guest system. In the confocal detection volume of similar to 10 mum(3) the guest molecules show two preferential orientations. A broad distribution of orientations of about +/- 17 degrees is observed around these two mean orientations. The mean orientations exhibit long-range order even over a distance of 2 mm with gradual variations on a micrometer scale. Over distances smaller than the lateral dimension of the confocal detection volume these variations disappear almost completely whereas the widths of the distributions remain qualitatively the same. The results do not point to the presence of a polycrystalline structure which contradicts the common picture of Shpol'skii systems. Show less
