Teflic acid

Direct fluorination of B(OTeF5)3 at 115° gives a 95% yield of the hypofluorite, FsTeOF, as a colourless gas which condenses to a colourless liquid below 0° and finally to a glass at about —80° the extrapolated bp is 0.6°. The chlorine derivative, ClOTeFs, the so-called teflic acid, HOTeFs, and the teflate anion, FsTeO (as caesium or tetraalkylammonium salts) are also useful synthons for a variety of metal derivatives, e.g. [Fe(OTeF5)3], " [Nb(OTeF5)6] ... 

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