Spectral diffusion of individual pentacene, terrylene, and dibenzanthanthrene molecules in n-tetradecane

The spectral stability of three guest molecules embedded in a quickly froze n n-tetradecane matrix has been investigated on a single-molecular level at liquid-helium temperature. In total, about 2500 spectral trajectories of 4 76 terrylene molecules, 328 dibenzanthanthrene molecules, and 252 pentacene molecules were recorded. Both line broadening and spectral jumps are analy zed and the latter are found to be mainly light induced. The spectral chang es in essence reflect the dynamics of the host matrix and the differences b etween the guest molecules may be reduced to differences in their pumping c ycles. (C) 2001 American Institute of Physics.