Photoelectron Spectra of Methane, Silane, Germane, Methyl Fluoride, Difluoromethane, and Trifluoromethane

An electron spectrometer which employs double focusing electrostatic plates is described. The photoelectron spectra obtained by bombarding methane, silane, germane, methyl fluoride, difluoromethane, and trifluoromethane with 21.22‐eV photons are presented. The experimental ionization energies are compared with theoretical and other experimental data, and molecular‐orbital assignments are made for the energy values obtained. Broad double maximum bands were observed in the case of methane, silane, and germane and are discussed in terms of Jahn–Teller distortion for the positive ions. Possible correlation of the methane spectrum with interstellar space data is also discussed.