MASS SPECTROMETRIC STUDY OF PHOTOIONIZATION .13. BORON TRICHLORIDE AND DIBORON TETRACHLORIDE

Mass spectra and ion yield curves for the molecule ions and various fragment ions of BCl3 and B2Cl4 are obtained by means of a combined vacuum ultraviolet monochromator and mass spectrometer. Shapes of ion yield curves, measured over the wavelength region from threshold to 600 Å, are discussed briefly. Ionization threshold values are used to calculate heats of formation of ions and radicals and to derive bond dissociation energies, including the boron-boron bond dissociation energy, D0(Cl2B-BCl2) = 3.80 eV (87.6 kcal mol-1), with estimated uncertainties of ±0.04 eV. © 1969, American Chemical Society. All rights reserved.