Thermodynamic properties of the B—Cl—F system from mass spectrometer investigations

Abstract

An effusion-mass spectrometric study of the B—Cl—F system results in thermodynamic data for the species BF₂(g), BCl(g), BCl₂(g) and BClF(g) in the temperature range 1253 to 1813 K, and for the species BFCl₂(g) and BClF₂(g) at 298 K. Heats of formation (ΔH^°_{f 298 K}) were calculated from the reaction thermodynamics for the species BCl(g)(33.1±1.2 kcal/mol), BCl₂(g)(–19.9±1 kcal/mol), BF₂(g)(–138.9±2.5 kcal/mol), BClF(g)(–76.5±2.5 kcal/mol), BClF₂(g)(–212.2±0.8 kcal/mol), and BFCl₂(g)(–153.3±0.8 kcal/mol). First, second and third bond strengths for the B—Cl and B—F bonds were obtained.