Radiofrequency discharges

This reaction provides a third indication of the usefulness of a radiofrequency discharge in the synthesis of compounds of low thermal stability. The more-stable (CFaljTej had been prepared by the interaction of CFj radicals, formed in the pyrolysis of (CF3)2CO, with a tellurium mirror (19). The less-stable (CFsljTe was not, however, observed in that experiment. 

Routes to B2CI4 and other diboron compounds (see section 10.2.4) depend on reduction of a B(III) compound. Synthesis of B2I4 makes use of reductive elimination, induced by a radiofrequency discharge ... 

Mavrodineanu R. and Hughes R. C. (1963) Excitation in radiofrequency discharges, Spectrochim Acta 19 1309-1307. 

The perfluorocarbons injected into Ar LPCAT represent the case represented by Eq. (8). On injection of a perfluorocarbon, such as CF4, C2F4, etc., luminous gas jet shrinks. However, OES data indicate that there is no signal discernible to F-containing species. Radiofrequency discharge of mixtures of Ar and perfluorocarbon shows F-containing species, indicating the... 

Thus, there are at least two important chemical differences between these reactions in (a) the radiofrequency discharge in an annular ozon-izer-type reactor at pressures near 200 torr, and (b) the microwave discharge in a cylindrical reactor at pressures of 12 or 50 torr. Under the microwave conditions, C2H2 is always produced (together with CH4) from H2 + CO and H2 + C02 (without cooling) form CO but no hydrocarbons. Obviously, it would be extremely useful to understand these phenomena. We have explored this situation a bit further, in the following manner. 

It should be noted that minor, but definite amounts of the three xylene isomers were formed in the radiofrequency discharge. The obser-... 

Mechanism. The available evidence is thus not consistent with the generally proposed mechanism of polymer formation based on the random build-up of a poly(phenylene) chain accompanied by hydrogenation (4) or the interaction with the hexatrienyl diradical (18). In the radiofrequency discharge of benzene (21), evidence was presented which indicated that the polymer contained consecutive para linkages suggesting poly(p-phenylenes). Schuler (20) observed that the polymer (C/H 1.03, M.W. 503) was a phenyl substituted aliphatic chain based on infrared evidence. Patrick and Burton have demonstrated that hydrogen atoms are not involved to any significant extent in polymer formation when liquid benzene is irradiated with a 1.5 Mev. source (18). 

The work described here is an attempt to systematize the study of benzene reactions in radiofrequency discharges. The only products isolated in these reactions were diphenyl, a liquid polymer and a solid polymer. The polymers appear to be polystyrenes. 

Some routes to (SN), that do not involve (SN)2 as an intermediate are available (see 15.2.12.3). The polymer is obtained in high yield from the reaction of (NSC1)3 with trimethylsilyl azide in acetonitrile - , by the electrochemical reduction of [(SN)5] salts ", and by radiofrequency discharge through (SN)4 vapors in a helium plasma. Other reactions that produce (SN), include the reduction of S2N" with azide ion, the solid state polymerization of impure S4N2 (recrystallized S4N2 does not polymerize) , and the oxidation of (SN)J with certain electrophiles . 

Bis(trifluoromethyl)mercury is useful in the preparation of numerous CF3 derivatives, especially of group IV elements. It was first prepared in 1949 by irradiation of CF3I and Hg in the presence of Cd. Alternative routes include radiofrequency discharge methods, for example, reaction of CF3 radicals witli HgXz or elemental mercury. Preparative scale quantities are best obtained by decarboxylation of mercury trifluoroacetate in the presence of carbonate. ... 

Inductively Coupled Plasma Discharge An electrodeless radiofrequency discharge produced by magnetically induced eddy currents in flowing argon confined in a quartz tube at atmospheric pressure. liquids, powders, gases 6000-10,000... 

Non-Thermal Radiofrequency Discharges Capacitive and Inductive Coupling of Plasma... 

CO2 Dissociation in Non-Equiiibrium Radiofrequency Discharges Experiments with Inductiveiy Coupied Piasma... 

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