J.V. Rau

Mass Spectrometry Study of C60 and C60-NiF2 Fluorination with Molecular Fluorine

Abstract Fluorination of [60]fullerene and [60]fullerene-NiF2(s) has been studied in situ by Knudsen cell mass spectrometry with admission of molecular fluorine. The fluorination processes were controlled in the temperature range 500 − 800 K at molecular fluorine pressure 10−4 − 10−5 atm. Temperature, time of fluorination and fluorine pressure were varied during the investigation. It was found that variation of these parameters did not lead to the selective fluorination. It was shown that NiF2(s) significantly influences the composition of the product mixture: a large amount of nickel difluoride in the system suppresses the fluorination reaction while the presence of a small amount promotes the selective fluorination. C60Fi18 (50% in the gas phase) was produced in our experiments under the following conditions: 20 h, 720 K, P(F2) = 2 10−4 atm in the prefluorinated (inner surface covered with NiF2(s) layer) Ni-reactor. An important point of the study was verification of the thermodynamic equilibrium in the...

Mass spectrometric and FTIR spectroscopic identification of FeF4 molecules in gaseous phase

Abstract The existence of a new compound – gaseous FeF4 – was assumed based on the results of Knudsen effusion mass spectrometry and FTIR spectroscopy. Hyperfluorination was achieved by applying excessive amount of CeF4(s) fluorinating agent in reaction with FeF3(s) at high temperatures (T=930–1050 K). The 758.5 cm−1 vibrational frequency was attributed to the Fe–F stretching mode of argon isolated FeF4 molecules.

MASS SPECTROMETRIC DETERMINATION OF COBALT TRIFLUORIDE SATURATED VAPOR PRESSURE. ENTHALPY OF FORMATION OF GASEOUS COF4 AND COF4

Knudsen cell mass spectrometry has been used for measuring the saturated vapor pressure of cobalt trifluoride. Enthalpy of sublimation of cobalt trifluoride, ΔSH0(CoF3,0 K), has been determined as 213.7±11.0 kJ/mol. Enthalpies of formation of the gaseous molecules CoF3, CoF4, and of the anion CoF4−, ΔfH0(0 K), have been recalculated as −572.3±32.0, −649.0±32.3 and −1265.3±40.6 kJ/mol, respectively. The electron affinity of cobalt tetrafluoride, EA(COF4), was found to be 6.4±0.3 eV.