MASS-SPECTROMETRIC STUDY OF C-60 AND C-60-NIF2 FLUORINATION WITH MOLECULAR FLUORINE

Fluorination of [60]fullerene and [60]fullerene-NiF2(s) has been studi ed in situ by Knudsen cell mass spectrometry with admission of molecul ar fluorine. The fluorination processes were controlled in the tempera ture range 500 - 800 K at molecular fluorine pressure 10(-4) - 10(-5) atm. Temperature, time of fluorination and fluorine pressure were vari ed during the investigation. It was found that variation of these para meters did not lead to the selective fluorination. It was shown that N iF2(s) significantly influences the composition of the product mixture : a large amount of nickel difluoride in the system suppresses the flu orination reaction while the presence of a small amount promotes the s elective fluorination. C60F18 (50% in the gas phase) was produced in o ur experiments under the following conditions: 20 h, 720 K, P(F-2) = 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 system. It was concluded that the equilibrium is not established in the system under study, and the fluorination is governed by kinetic factors.