Fluorine oxyhalides

Much less is known about ruthenium oxyhalides than about the osmium compounds. The only compound definitely characterized [24] is RuOF4, synthesized by fluorination of Ru02, condensing the product at -196°C. It loses oxygen slowly at room temperature, rapidly at 70°C. 

Because the highest oxidation state of Cr is + 6, it forms oxyhalides that have the formula Cr02X2 and are known as chromyl halides. However, in the case of the fluorine compound, CrOF4 is also known, as well as some oxyhalides having the formula CrOX3. Some reactions that yield chromyl halides are the following ... 

The oxyfluorides of La(III) and Y(III) also contain (67, 142, 143) octacoordi-nated metal ions (MO4F4), the metal ions being situated between layers of oxygen and fluorine (cf. other oxyhalides). Zachariasen [142) was able to obtain both rhombohedral and tetragonal modifications for La and Y oxyfluorides with the following M—0 and M—F distances. 

Antimony forms polymeric oxyhalides, and not metallic as in BiOCl. The fluoride, SbOF, has been prepared in two forms V, with a ladder structure, and iM which has a layered structure. Both forms have a trigonal bipyramidal structure about antimony with three oxygens, one fluorine and one lone pair. Structural parameters are given in Table 15, from which it can be seen that L-SbOF heads the table as the nearest to an ideal fit for trigonal bipyramidal geometry. 

Since fluorine is difficult to prepare and manipulate, the anhydrous fluorides and oxyfluorides are prepared by the action of anhydrous hydrogen fluoride on other halides or oxyhalides of vanadium.1... 

The noncatenated halides include the relatively inert sulfur hexafluoride and the highly reactive tetrafluorides of sulfur, selenium, and tellurium. SFg( ) is useful in insulators and pressurized athletic equipment. SF4( ) is an important fluorinating agent. Two important oxyhalides are thionyl and sulfuryl chloride. The former is particularly useful in preparing anhydrous metal halides. 

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