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Some reactions of tetramethyldiarsine and related compounds

University of British Columbia

Tetramethyldiarsine Is found to add across the double bond of fluoroölefins of the type CF₂=CFX (X = F,Cl,Br), to give addition products. Thus 1:1 adducts, i.e. (CH₃)₂As-CF₂-CFX-As(CH₃)₂, are obtained in the reactions of tetramethyldiarsine and CF₂=CFX (X = CI,Br). The reaction of tetramethyldiarsine and tetrafluoroethylene, however, gives (CH₃)₂Aa-(CF₂-CF₂)₄-As(CH₃)₂, a 1:4 adduct. Iodotrifluoroethylene and tetramethyldiarsine react to give an adduct which Is unstable in air, but this reaction yields dimethylperfluorovinylarsine, b.p. 71°. The above arsine is also prepared by the reaction of iododimethylarsine and iodotrifluoroethylene in the presence of mercury. Tetramethyldiarsine does not react with ethylene at 20°. Bromotrifluoroethylene does not give an addition product with tetrakis(trifluoromethyl) diarsine. Hexafluoro-2-butyne reacts with tetramethyldiarsine at 20° to yield a 1:1 adduct, trans-1,2-bis(dimethylarsino)-1,2-bis(trIfluoromethyl)ethylene. Tetrakis (trifluoromethyl)diarsine and arsenobenzene do not react with hexafluoro-2—butyne to give adducts. Iodotrifluoromethane reacts with arsenobenzene to produce iodophenyltrifluoromethylarsine, phenylbis(trifluoromethyl) arsine and phenyIdliodoarsine. The mechanism of this reaction has been suggested. The iodophenyltrifluoromethylarsine reacts with silver chloride to yield chlorophenyltrifluoromethylarsine. The chloroarsine and bis(trifluoromethyl)arsine react with the elimination of hydrogen chloride to form a diarsine, which Is believed to be the symmetrical 1,2-bis(phenyl)-!, 2-bis (trifluoromethyl) diarsine. This same diarsine is probably formed by the coupling of two iodophenyltrifluoromethylarsine molecules in the presence of mercury. Paranitroarsenobenzene reacts with iodotrifluoromethane with explosive violence. Trimethylarsine does not undergo exchange reaction with bromotrifluoroethylene to give dimethylperfluorovinylarsine. Hexafluoro-2-butyne does not give an addition compound with iodo- dimethylarsine. Tetrakis(trifluoromethyl)diphosphine fails to yield adduct with bromotrifluoroethylene at 120°. Hexafluoro-2-butyne also does not give adducts with tetrakis(trifluoromethyl)diphosphine, hexa-phenylditin and hexabutylditin.

Text

2011-10-20

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http://hdl.handle.net/2429/38113

Chemistry

University of British Columbia

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