CHARACTERIZATION OF HEXACARBONITRILE TRIIMIDAZO TRIAZINE (HTT) USING EXPERIMENTAL AND MODELED ULTRASOFT X-RAY-ABSORPTION SPECTRA

The characterization of a large oligomeric molecule containing primari ly carbon and nitrogen using ultrasoft X-ray absorption spectroscopy ( USXAS) above the carbon and nitrogen K edges is discussed. Specificall y, we have used carbon and nitrogen ls core level USXAS spectra to cha racterize the electronic structure of hexacarbonitrile-triimidazo-tria zine (HTT) for the first time. The electronic spectrum above the carbo n and nitrogen edges allowed us to distinguish between several potenti al geometric structures. Core spectra of several potential structures for HTT were simulated using a linear combination of core level spectr a from several smaller constituent molecules including imidazole (IM), 4,5-dicyanoimidazole (DCIM), and s-triazine (TZ). By starting with sm aller molecules which contain delocalized pi-systems, we propose that a building block approach to USXAS spectral modeling, commonly used in the analysis of nonconjugated systems, can be used for molecules cont aining extended pi-systems. The comparison of HTT simulated spectra wi th the experimental spectrum provides substantial insight into the com plex HTT structure and eliminates alternate C5N4 structural possibilit ies.