The fluoride also coprecipitates from halogen fluoride solutions with XeF2 and complexes of XeF2 but not with XeF4.7,8 Recently, Avrorin et al.1 23456789 have reported the preparation of a higher fluoride of radon, either RnF4 or RnF6, and a water-soluble oxide, Rn03, in tracer experiments with isotope 222Rn. They hydrolyzed complex mixtures of products that had been obtained by heating radon, xenon, fluorine, bromine pentafluoride, and either sodium fluoride or nickel fluoride. Part of the radon volatilized on hydrolysis and part remained in the aqueous phase, suggesting the formation of Rn03. However, Avrorin et al. failed to closely examine the contents of the aqueous phase. In this note we report the results of experiments that we have carried out, using larger amounts of reagents and similar conditions, in an effort to confirm their findings.
Experimental SectionA Monel reactor (9.05-mL volume) attached to a Monel valve was loaded at room temperature with either NiF2 (16.8-27.7 mmol) or NaF (39.3-42.9 mmol), cooled to -195 °C, and charged with BrFs (15.5-46.4 mmol), 222Rn (49-221 µ ), xenon (0.54-0.57 mmol), and fluorine (54.7-57.1 mmol). Each mixture was heated at 250-265 °C for approximately 40 h. The excess fluorine was pumped off at -195 °C, and BrF5 and uncomplexed XeF6 were vacuum distilled from the reactor at 0 °C. (The XeF6 product was complexes by NaF but not by NiF2). Products remaining in the reactor were then hydrolyzed with 8-15 mL of 0.10 M aqueous Xe03 solution at 0 °C. Radon in the hydrolysate was analyzed by measuring the emissions of its daughters, 214Pb and 214Bi, in equilibrium with their parent.4 The hydrolysate was centrifuged and the supemate transferred to a separate container; the radon was then analyzed in each fraction. The supemate was flushed with nitrogen for 5-10 min and the residue stirred with 10 mL of either water, 0.10 M Xe03 solution, or 1 KI solution; after 4 h, the analyses were repeated.To determine the behavior of radon in simpler mixtures, several experiments were carried out with only radon, fluorine, and NiF2 or with only radon, fluorine, and NaF. Each mixture was heated at
