Dresden 2009 – scientific programme

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 25: Diffusion and Dynamics

CPP 25.6: Talk

Wednesday, March 25, 2009, 16:45–17:00, ZEU 160

Diffusional and orientational dynamics of various single terrylene diimide conjugates in mesoporous materials — •Florian Feil, Christophe Jung, Johanna Kirstein, Jens Michaelis, and Christoph Bräuchle — Department of Chemistry und Biochemistry, Ludwig-Maximilians-Universität München, Butenandtstrasse 11, 81377 München (Germany)

Mesoporous silica materials are ideally suited as host-guest systems in nanoscience with applications ranging from molecular sieves, catalysts, nanosensors to drug delivery systems. For all these applications a thorough understanding of the interactions between the mesoporous host system and the guest molecules is vital. Here, we use single molecule spectroscopy to study the dynamics of three different terrylene diimide dyes acting as molecular probes in hexagonal and lamellar mesoporous silica films. The diffusion behaviour in the hexagonal phase is represented by the trajectories of the single molecules which are highly structured and thus provide information about the underlying host structure, such as domain size or the presence of defects inside the host structure. In the lamellar phase, the differences between the three guests are quite dramatic. Two populations of diffusing molecules could be observed: one with parallel orientation of the molecules to the lamellae and the other with perpendicular orientation. Additionally, switching between the two populations was observed. These data provide new insights into host-guest interactions like the influence of the molecular structure of the guest molecules on their diffusional as well as on their orientational behaviour in structurally confined guest systems.