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 saturat ed vapor pressure of cobalt trifluoride. Enthalpy of sublimation of co balt trifluoride, Delta(8)H(0)(CoF3,0 K), has been determined as 213.7 +/- 11.0 kJ/mol. Enthalpies of formation of the gaseous molecules CoF 3, CoF4, and of the anion CoF4-, Delta(f)H(0)(0 K), have been recalcul ated as -572.3 +/- 32.0, 649.0 +/- 32.3 and -1265.3 +/- 40.6 kJ/mol, r espectively, The electron affinity of cobalt tetrafluoride, EA(COF4), was found to be 6.4 +/- 0.3 eV. (C) 1997 John Wiley & Sons, Ltd.