PHOTOELECTRON-SPECTRA AND MOLECULAR-PROPE RTIES .155. ISOMERIC THIONITRILES - H3C-N=S AND F3C-S=M

Thermal fragmentation of the well-designed precursor molecules, 3,4-di hydro-1,2,3-thiadiazole and bis(dimethylamino)sulfide as well as N-flu oroformylimino-trifluoromethyl-sulfurfluoride allows to generate the k inetically unstable thionitrosyl derivatives H3C-N=S and F3C-S=N in th e gasphase and to characterize them by their photoelectron spectroscop ic ionization patterns. The assignment of the He (I) PE-spectra, which remain after digital subtraction of all PE bands from thermolytic sid e-products, is achieved via Koopmans' correlation with eigenvalues fro m geometry-optimized MNDO or ab initio calculations and is supported b y a radical cation state comparison with chemically related molecules such as H3C-N=O or F-S=N.