Jet cooled exciplexes

The very first fluorescence spectra of jet-cooled exciplexes indicated the existence of two types of ground-state van der Waals adducts. For instance, the anthracene-dimethylaniline system displayed two types of cluster bands in the fluorescence excitation spectrum broad ( 150 cm ) and structureless, leading to typical ex-ciplex emission, and narrow (1 cm ), leading to resonance-type emission [10, 20]. It was assumed that they are due to different 1 1 adducts, distinguished by different geometries. Recently, laser-based techniques were developed that allow the discrimination of different species. One is hole-burning spectroscopy and another— mass-selected photoionization. 

Itoh s group and also Tramer, Piuzzi and their co-workers used this method extensively for the study of jet-cooled exciplexes. Examples of hole-burning spectra are shown in Figures 2 and 3. 

The Farkas Center for Light Induced Processes is supported by Minerva Gesell-schaft mbH. Special thanks and appreciation are due to my co-workers who helped me in untangling some of the mysteries of jet-cooled exciplexes Drs. Oded Anner, Hanna Zuckermann, Wolfgang Drescher, Eyal Zingher and Shai Kendler and Mr. Ismael Zarura. 

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