PREPARATION AND SPECTROSCOPIC CHARACTERIZATION OF A THIN POLYMER FILM IN ULTRA HIGH-VACUUM - 2,5-DISTYRYLPYRAZINE

The UHV-preparation and -characterization of thin, highly ordered polymer films of 2,5-distyrylpyrazine is reported. Monomer films were evaporated from a Knudsen cell. Subsequent photo-oligomerization occurs by illumination with UV light. The desorption behavior of the monomers and the lower oligomers was studied by temperature-programmed desorption mass spectrometry (TDS). The photoreaction was monitored in situ by high resolution electron energy loss spectroscopy (HREELS) in the range of electronic transitions. The information obtained from the loss spectra are compared to those from absorption and fluorescence spectroscopy. The results are discussed in the framework of the calculated electronic structure of related compounds.