Patrick N. Walsh

Infrared Emission Spectrum of Gaseous HBO2

The infrared emission spectrum of the vapor phase of the B2O3(l)–H2O(g) system has been studied at elevated temperatures over the region 700–4000 cm—1. Characteristic bands were found near 3680, 2030, and 1420 cm—1, and approximate B10–B11 and H–D isotope shifts measured. It is shown that these bands arise from the molecule HBO2. The intensity of the 2030 cm—1 band was studied as a function of both temperature and water pressure. The intensity vs temperature measurements lead to a heat of formation, ΔH0o, of —135.0±3 kcal/mole for HBO2(g). The spectroscopic data, considered in the light of our analysis of the B2O3(g) infrared spectrum, are compatible with the structure O=B–O–H in which the OBO group is linear and the H is off‐axis. The force constants are found to resemble those determined for B2O3(g). Complete vibrational assignments are given for HBO2(g) and its trimer (HBO2)3(g), a species which has recently been shown to exist in this system. Thermal functions have been computed for both molecules ove...

Infrared Emission Spectra of Gaseous B2O3 and B2O2

The infrared emission spectra of gaseous B2O3 and B2O2 in the temperature range 1400–1800°K have been studied in the region 700–4000 cm—1. Distinct bands were found for natural B2O3 at 2040, 1302, and 742 cm—1, and the B10–B11 isotope shifts measured. From the isotope shift data and other considerations the B2O3 molecule has been assigned a V structure having C2v symmetry. A force constant analysis has been made and a frequency assignment is given from which thermal functions have been computed. The calculated force constants are consistent with the high stability of the molecule. Only one emission band of gaseous B2O2, at 1890 cm—1, has been observed. A linear D∞h structure was assumed and a frequency assignment and thermal functions estimated.

THE APPLICATION OF THE TIME-OF-FLIGHT MASS SPECTROMETER TO THE STUDY OF INORGANIC MATERIALS AT ELEVATED TEMPERATURES*

Summary A Bendix time-of-flight mass spectrometer has been adapted for use in the study of the thermodynamics of chemical reactions at elevated temperatures. The design of the high temperature furnace, which is capable of heating a cell to 2625°K, and its attachment to the spectrometer are discussed in detail. The following chemical reactions have been studied and compared with results from magnetic focusing instruments and by other methods. The stability and sensitivity of the mass spectrometer, the range of linearity of the multiplier, and the determination of appearance potentials are discussed.