Photoelectron spectroscopy of high temperature vapors. V. HeI spectra of GaX3 and InX3 (X = Cl, Br, I)

Abstract
The HeI (584 Å) photoelectron spectra of GaX3 and InX3 (X=Cl, Br, I) are reported. All peaks are classified and the results are compared with spectra of the boron trihalides to bring out systematic variations caused by substituting different halogens and central atoms. A revision of the classification of the outermost e′ and e″ peaks in the spectra of BBr3 and BI3 is suggested. The spectra of GaI3 and InI3 exhibit splitting of the band due to ionization from an e″ MO (in D3h symmetry), which suggests that either the neutral ground state or the first excited 2E″ state of the ion is pyramidal.