Oxidative-fluorinating agents

Stable noble-gas compounds have no industrial uses as of this writing but are frequently utilized in laboratories as fluorinating and oxidizing agents. Xenon difluoride and xenon tetrafluoride are relatively mild oxidative fluorinating agents and have been used for the preparation of phosphoms, sulfur, tellurium. 

The chemical shift of XeF2 (5F = -176) is provided, since this compound has been used by organic chemists as an oxidative fluorinating agent. 

Caution Phenylsulfur trifluoride and by-products (e.g., hydrogen fluoride from hydrolysis) are toxic, and all manipulations should be carried out in a good hood. Silva difluoride is a powerful oxidative fluorinating agent and reacts vigorously with many organic materials. These reagents should not be allowed to come in contact with the skin. 

The monofluoro (94) and difluoro derivatives (95) were isolated when a solution of potassium fluoride in sulfolane reacted with 4,5-dichloro-1,2,5-thiadiazole. Careful control of the reaction conditions allowed production of mainly 95, whereas 94 became the major product when oxidizing fluorinating agents were employed (e.g., XeF2, BrF3, AgF2). Open-chain products were also found (82CB2135) (Scheme 34). 

Sulfur tetrafluoride acts as an oxidative fluorinating agent towards organometalloid compounds. Triphenylphosphane and triphenylarsane are converted at 100-150C into difluoro-triphenyl-l5-phosphane (16) and difluorotriphenyl-l5-arsane (17), respectively.219... 

On the other hand, oxidizing fluorinating agents like silver difluoride, xenon difluoride, or bromine trifluoride replace one chlorine group and then cleave the sulfur-nitrogen bond [5(5]. 

The same authors showed that platinum hexafluoride, which is a somewhat weaker oxidative fluorinating agent than KrF+, can also oxidize NF3, though the yield and purity of the NF4+ fluoroplatinate formed as a dark red solid were low. The pure salt was prepared for purposes of comparison by the thermal reaction at 125°C between NF3, F2, and PtF6. The reaction between NF3 and the hexafluoride was carried out either in HF solution at 25°C or under ultraviolet irradiation in the gas phase, also at ambient temperature. In each case the vibrational spectrum of the product showed the presence of a tetraflu-oroammonium salt, but the product was a mixture of fluoroplatinate and polyfluoroplatinate which could not be purified by extraction with liquid HF. 

With IrFe the marginal ability to add F" and the ability to oxidize F to V2F2 combine to render it a most effective oxidative fluorinating agent. When ONF and IrFs are mixed in approximately equimolar quantities at 20 °C, a reaction occurs, the overall stoichiometry of which approximates to... 

The [C6F5XeF2] ion (formed as the [Bp4j salt from C6F5BF2 and Xep4) is an extremely powerful oxidative-fluorinating agent, e.g. it converts I2 to IF5. 

Lewis acid fluorides to form KrF+ and Kt2F salts. The KrF+ cation is the strongest oxidative fluorinating agent known. 

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