Effusion-mass spectrometric study of the thermodynamic properties of BO– and BO –2

Abstract

Thermodynamic properties were obtained for negative ions of the lower boron oxides by means of the Knudsen cell-mass spectrometer method over the temperature range 1623-2100 K. Second and third law studies were conducted involving negative ions with neutral atoms and molecules for the reactions BO(g)+Cl^–(g)= BO^–(g)+ Cl(g), BO₂(g)+ Cl^–(g)= BO^–₂(g)+Cl(g). The heats of formation ΔH_f298 for the negative ions BO^– and BO^–₂ were obtained from the reaction thermodynamics as –71.9±2.0 and –159.3±2.0 kcal/mol, respectively. The electron affinities were E.A.(BO)= 71.9±2.0 kcal/mol and E.A.(BO₂)= 82.3±3.0 kcal/mol.