The He 584 Å Photoelectron Spectra of Analoga of Thiathiophthene

The photoelectron spectra of the four oxygen and nitrogen analogs of thiathiophthene 1 to 4 are reported and discussed. The first two bands are assigned to ionization from the π- and n-molecular orbitals on the basis of CNDO/2 calculations. The assignment of bands and to ionization from π-molecular orbitals is suggested.