Raman spectra of the solutions some inorganic fluorides in anhydrous hydrogen fluoride.

Abstract

The laser Raman spectra for the solutions KrF 2 (1,5÷7,5), XeF 2 (0.15÷16.5), ClOF 3 (1.8÷9.2), ClOF 2BF 4 (1.3÷2.8) and ClOF 2AuF 6 (0.3÷2.8 mole·1 −1) in anhydrous HF have been recorded. The spectral study gives an evidence for a strong self-ionisation of ClOF 3 and its salts and for a weak one of XeF 2 in HF (see table): ClOF 3 [ClOF 2BF 4 ClOF 2AuF 6] = ClOF 2 + + HF 2 −(BF 4 −, AuF 6 −) XeF 2 = FXe δ+—[FHF] δ− = XeF 2 ···FXe δ+—[FHF] 1 XeF 2 ClOF 2HF 2 ClOF 2BF 4 ClOF 2AuF 6 ν Δν 1/2 ν Δν 1/2 ν Δν 1/2 ν Δν 1/2 476(47) 47 1333p 10 1334p 8 1334 6.5 539(100) 76 1321p 10 1322p 8.5 1327 7.0 474(37) 52 736p 30 742p 22 748dp 15 510(95) 25 705dp 20 711dp 14 714dp 10 540(100) The existence of ClOF 3 adducts with HF was confirmed by results of thermal analysis with these data the melting point-composition diagram was constructed. Theoretical estimations showed that the value δν 1 2 of ν 1 and ν 2 ClOF 2 + decreases with the increase of solution concentration which is connected with limitation of orientational move of soluble molecules. The orientational time for ν 1 is 1.63 ns (HF 2 −), 1.31 ns (BF 4 −) and 1.06 ns (AuF 6 −), and for ν 2 -three times smaller accordingly the previous values for ν 1. The data obtained in this study are discussed together with existing data on solid substances.