1619-84-7

An improved method has been used to synthesize perfluoroazo-2-propane. Pyrolysis over the temperature range 450-514 K in a static system has been shown to be a homogeneous, first-order process. No pressure dependence was observed in the presence of excess inert gas (SF6). The only products were nitrogen and perfluoro-2,3-dimethylbutane. The rate constant (k) for the decomposition process is given by: log(k/s-1) = 16.7 ± 0.2 - (9856 ± 109)/T These results lead to a straightforward mechanism for the decomposition process (1) i-C3F7N2 i-C3F7 → i-C3F7N2 + i-C3F7 (2) i-C3F7N2 → i-C3F7 + N2 (3) 2i-C3F7 → (i-C3F7)2 The results are compared with those for other azo compounds.

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Perfluorinated carbenes like :CF2 and:C(CF3)2 do not react with perfluoro-2-aza-1-propene (1) to yield the expected aziridines 2 and 8, respectively.Assuming the intermediacy of bis(trifluoromethyl)amide anion (4) the formation of the well known dimer of 1, (CF3)2N-CF=N-CF3 (3), can be explained as well as the formation of (CF3)2N-CF2H (5) and (CF3)2N-CF2Br (6).From 1,1,1,3,3,3-hexafluoro-2-propanimine (10) and :C(CF3)2 we did not obtain the aziridine 11 but (CF3)2C=N-CH(CF3)2 (12), which is formed by insertion into the NH-bond. - The structure of C4Cl8N2, which is formed as a by-product of the synthesis of perchloro-2-aza -1-propene, has been determined: Cl2C=N-CCl2-N=CCl2.

Bis(trifluoromethyl) sulfide, tetrafluoro-1,3-dithietane, and bis(trifluoromethyl) sulfoxide undergo oxidative addition when photolyzed with trifluoromethyl hypochlorite to form a new family of sulfuranes, bis(trifluoromethyl)bis(trifluoromethoxy)sulfurane (1) and tetrafluoro-1,3-tetrakis(trifluoromethoxy)dithietane (3), and of sulfurane oxides, bis(trifluoromethyl)bis(trifluoromethoxy)sulfurane oxide (2). Compounds 1 and 2 are hydrolyzed to bis(trifluoromethyl) sulfoxide and bis(trifluoromethyl) sulfone, respectively. Pyrolysis of 1, 2, or 3 gives bis(trifluoromethyl) sulfide, bis(trifluoromethyl) sulfoxide, and tetrafluoro-1,3-dithietane, respectively, plus bis(trifluoromethyl) peroxide. With primary amines, 1 and 2 yield N-alkylbis(trifluoromethyl)sulfimides and sulfoxyimides, and with N,N′-diethylaminotrimethylsilane, imine formation occurs. Sulfurane oxide 2 forms a new type of stable sulfurane oxide (4), bis(trifluoromethyl)bis(hexafluoroisopropylidenimido)sulfurane oxide, with lithium hexafluoroisopropylidenimine. Sulfurane 1 acts in a similar manner with the nucleophile but the sulfurane 5 is not isolated. Compounds 1 and 2 form α,α,α-(trifluoromethyl)anisole derivatives with substituted phenols. Secondary and tertiary alcohols are dehydrated by 1 or 2 to olefins but symmetrical alkyl ethers result when primary alcohols are reacted.