Mass Spectrometric Determination of Cobalt Trifluoride Saturated Vapour 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, Æ8H0(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-, ÆfH0(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.