Study of the ionization process BF+(X2∑+)â†� BF(X1∑+) by high-temperature photoelectron spectroscopy

Abstract

The He I photoelectron spectrum of the BF molecule, produced by passing BF₃ over heated boron, has been recorded. Only one band was observed and it was assigned to the ionization BF⁺(X²∑⁺)â†� BF(X¹∑⁺). For this band the adiabatic and vertical ionization potentials were coincident at 11.12 ± 0.01 eV and analysis of the observed vibrational structure gave w_e= 1765 ± 20 cm^–1 and r_e= 1.208 ± 0.005 Å for the BF⁺(X²∑⁺) state. Estimates of the first and higher vertical ionization potentials of BF are made by ab initioΔSCF and Hartree–Fock–Slater calculations.