Inorganic fluorine chemistry : low-temperature fluorination of the main group elements and some metal fluorides
The U.V. and laser induced photolysis of noble-gas/fluorine mixtures have been studied at -196C. The U.V. photolysis of krypton/fluorine and xenon/fluorine mixtures for 12h gives approximately a 30% yield of KrF2 and XeF2 respectively. Whilst photolysis with an argon ion laser gives comparable yields after only 30 minutes. Two temperature dependent phases of KrF2 were observed. Laser photolysis of oxygen/fluorine mixtures at -196C gives O4F2 and O2F2 and of UF5/F2 mixtures gives UF6. The photolysis of noble-gas /fluorine mixtures with added Lewis acids were also examined. A 1:1:2 mixture of fluorine, krypton and MF5 (M= As, Sb, I), photolysed at -196C using either U.V. or argon ion laser radiation also gives KrF2. There is no evidence of reaction with MF5 at -196C. Warming of the resultant mixtures affords Kr2F3+SbF6, a- and b- KrF+Sb2F11-, a-KrF+AsF6-, KrF+As2F11 and KrF2.nIF5 (n=1-3) at various temperatures which have been identified by Raman Spectroscopy. Investigations of reactions involving fluorine atoms, produced from elemental fluorine by the catalytic method, were made. Reactions involving krypton/fluorine and xenon/fluorine mixtures gave KrF2, XeF2 and XeF4 respectively. Also in this work an attempt was made to prepare a possible (Xe-I) containing species by the reaction between Xe2+Sb2F11- with iodine. Further investigations need to be carried out to clarify the results obtained.