The study of interaction of fluorine atoms with chromium and its fluorides

Abstract

The reaction of atomic fluorine with nonaqueous CrF3 is accompanied by CrF formation. The presence of crystallized water in the initial CrF3 leads to the change of the process mechanism and to the change of its direction. The interaction of fluorine atoms with CrF3·4H2O, unlike the reaction with CrF3. is accompanied by the considerable heating of a solid reagent and by the formation of HF, CrO2F2 and O2. The mechanism of fluorination of CrF3·4H2O has been suggested on the basis of which the process starts with a strongly expressed exothermal reaction of the fluorine atoms with the crystallized water.The interaction between has atomic fluorine and the solid CrF5 is not observed in the temperature range of 90-273 K. It was found that the destruction of atoms on the reaction surface takes place under these conditions as a result of the recombination and attempt of obtaining CrF6 has been failed.The interaction of the atoms of fluorine with the solid chromium has been studied in the temperature range of 295-650 K. It was found that the recombination of atoms occurs up to 550 K on the metal surface, without evidence of the visible chemical interaction of fluorine with chromium. At a temperature above 550 K the metal ignition was observed in the atomic fluorine flow. Such substances in the reaction products as CrF6, CrO2F2, CrF4 and CrF5 were found. The yield of various reaction products depends on the metal burning conditions and impurities of oxygen in fluorine.