Sulphur hexafluoride, reaction

Two mole per cent sulphur hexafluoride caused only a slight reduction in G(H2). By contrast, in gaseous HC1 2 x 10-2 mole % sufficed to halve the yield of hydrogen from electron reactions. The difference is readily understood since the HC1 concentration in the liquid is such that the reaction... 

Disulphur decafluoride is thermally less stable than sulphur hexafluoride. Its tendency to react with glass and mercury precludes kinetic investigations in conventional pyrex apparatus, but Trost and McIntosh172 have studied the thermal decomposition in a copper vessel fitted with a diaphragm manometer. Within the experimental error of + 3 % the stoichiometry of the reaction was... 

Sulphur Hexafluoride. As a result of a chemical laser study it has been proposed that collision-induced dissociation (78) rather than abstraction (79) is the principal path in the reaction of atoms of energy up to 430 kJ mol with SF . 

Transient Species.—Pioneering studies by Johnson and co-workers have shown that monomeric thioformaldehyde is generated when methane reacts with small sulphur-containing molecules, such as carbon disulphide, carbonyl sulphide, or hydrogen sulphide, at low pressure in a radio-frequency discharge tube. On the basis of these results, Johns and Olson prepared thioformaldehyde, under slightly different conditions, from dimethyl disulphide in the presence of sulphur hexafluoride. The reaction path suggested was ... 

It is apparent that substitution of fluorine for hydrogen initially causes a reduction in reactivity towards the electrophilic oxy n atom, but tetra-fluoroethylene is anomalous. A further study has indicated that substitution by trifluoromethyl has a strong deactivating effect compared with methyl, which has an activating effect. A study of the reactions of nearly thermal i F atoms, produced by F(n,2n) F and moderated by collisions with an excess of sulphur hexafluoride, with fluoro-oleflns (modes of addition were identified by scavenging the radicals produced with hydrogen iodide) has indicated that F atoms react preferentially with less-fluorinated olefins, and at the less-fluorinated end of a particular olefin. ... 

C,Fs-C N+ 2C1F->CjF5 CF, NC1 4.C,F,N N C,F, -1- Cl,). Pyrolysis (at 180°C) or photolysis of the CIF-adduct of theimineC,F,-N CF, ((CF,)-(C,F5)NC1, also obtainable via reaction of OF with (CF,XC,Fj)NH] yields the tetrasubstituted hydrazine (CF,XC,Fj)N N(C,FsXCF,). Reaction of chlorine monofluoride with potassium thiocyanate at — 30°C yields INW-dichlorotrifluoromethylamine, sulphur chloride pentafluoride, chlorine, potassium fluoride, and traces of sulphur hexafluoride and hexafluoroazo-methane. ... 

Solid sulphur, selenium, and tellurium inflame in fluorine gas at ordinary temp. sulphur burns to the hexafluoride, SF6. The reactivity of sulphur or selenium with fluorine persists at —187°, but tellurium is without action at this temp. Hydrogen sulphide and sulphur dioxide also burn in the gas—the former produces hydrogen fluoride and sulphur fluoride. Each bubble of sulphur dioxide led into a jar of fluorine produces an explosion and thionyl fluoride, S0F2, is formed but if the fluorine be led into the sulphur dioxide, there is no action until the sulphur dioxide has reached a certain partial pressure when all explodes. If the fluorine be led into an atm. of sulphur dioxide at the temp, of the reaction, sulphuryl fluoride, S02F2, is formed quietly without violence. Sulphuric acid is scarcely affected by fluorine. 

---