The emission band system of GeF₄⁺

Abstract

A discrete electronic emission spectrum around 400 nm is observed at a low rotational temperature following electron impact ionization of a molecular beam of GeF₄. The narrow rotational envelope of the bands confirms that the emitter is the parent molecular ion of GeF₄. By comparison with a recent study of fast ion beam excitation of GeF₄ and with photoelectron data, the spectrum is assigned to GeF₄ ⁺ . The spin-orbit splitting constant of has a small negative value, and this state exhibits Jahn-Teller distortion from tetrahedral symmetry with both v ₄ (t ₂) and v ₂ (e) being Jahn-Teller active vibrations. The results are compared with those from the analogous spectra of CF₄ ⁺ and SiF₄ ⁺.