Photoelectron spectra and molecular properties .155. Isomeric thionitriles: H3C-N=S and F3C-S=M

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