Propanes halogenated

The relative quantum yield for the production of I( P- 2) atoms from -CjFyl and 11-C3F7I has been measured as a function of wavelength between 265 and 336 nm (199). For both molecules the quantum yield is found to be 1 within experimental error up to 298 nm. From that wavelength to 336 nm, the quantum yield decreases for each of these molecules, but the yield decreases faster for the 11-C3F7I. These results could be explained by either a curve crossing, or by the excitation of a weak absor-tion to the 3QX as well as the 3Qq state. In light of the results obtained in other alkyl halides the former explanation seems more likely. 

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Lag. M., Omichinski, J.G, Dybing, E., Nelson, S.D. Soderlund, E.J. (1994) Mutagenic activity of halogenated propanes and propenes effect of bromine and chlorine positioning. Chem.-biol. Interact., 93, 73-84... 

Ratpan, F. Plaumann, H. (1988) Mutagenicity of halogenated propanes and their methylated derivatives. Environ, mol. Mutag., 12, 253-259... 

The 1,3-dichlorohexafluoropropane is once again assumed to arise by the addition of CF2C1 radicals to the CF3 formed by disproportionation processes. Its rate of formation is much slower than in the case of the photolysis of 1,3-dichlorotetrafluoroacetone, probably due to the reduced radical concentration. The analysis is obviously incomplete because no corresponding halogenated propanes, from the addition of CFCh radicals to CF2, have been observed, probably owing to their low volatility. 

In particular St levik s conformational study of a series of halogenated propanes has contributed to our understanding of the flexibility of molecules with two axes of internal rotation. The coexistence of as many as three conformers has been found in several instances. For these halopropanes the structures of the coexisting conformers have been determined as well as their mole fractions. The molecules are quite rigid, and from the study of the u-values the conclusion has been drawn that the torsional potentials are harmonic in the minimum regions. 

Formation of Both Components of the 1,2-Bond Elimination in 1,3-Halogenated Propanes... 

Alternatively, allyl halides are fluorinated with metal fluorides in general, yields are poor except for cyclic systems (Table 7), and for fluorinated halogenated propanes, e.g. 2, in which the fluoriiiation proceeds through an S>,2 mechanism. ... 

THERMODYNAMIC QUANTITIES OF TWO HALOGENATED PROPANES. ANGELLCL J CHEM ENG DATA... 

Among the volatile anesthetics the halogenated propanes (XXXV) are claimed to be useful, non-flai able inhalation anesthetics in mice with a low order of heptatotoxicity. ... 

Disposal. Moderate amounts of chlorine ttifluoride or other halogen fluorides may be destroyed by burning with a fuel such as natural gas, hydrogen, or propane. The resulting fumes may be vented to water or caustic scmbbers. Alternatively, they can be diluted with an inert gas and scmbbed in a caustic solution. Further information on disposal of halogen fluorides is available (115—118). 

Reactions other than those of the nucleophilic reactivity of alkyl sulfates iavolve reactions with hydrocarbons, thermal degradation, sulfonation, halogenation of the alkyl groups, and reduction of the sulfate groups. Aromatic hydrocarbons, eg, benzene and naphthalene, react with alkyl sulfates when cataly2ed by aluminum chloride to give Fhedel-Crafts-type alkylation product mixtures (59). Isobutane is readily alkylated by a dipropyl sulfate mixture from the reaction of propylene ia propane with sulfuric acid (60). 

In an analogous fashion the oxidative coupling of 1,3-diselenols is used for the preparation of 1,2-diselenolanes, the precursors being obtained by a variety of methods (see Chapter 4.35). Similar reaction s have been used for the preparation of 1,2-thiaselenolanes. Substituted propane-1,3-diselenones (287) are oxidized by halogen to the corresponding 3,5-diamino-l,2-diselenolylium chloride (288) (67AJC1991). 

Ammonia, halogen-ated hydrocarbons, propane, ethylene, and others... 

Metal-halogen exchange of 10-bromo-5-ethyl-5//-dibenz[/>,/]azepinc (52) with butyllithium followed by quenching with acetone yields the propan-2-ol 53.214... 

Triathyl-siliciumhydrid reduziert Halogen-alkane bei Aluminiumchlorid-Katalyse nach einem polaren Mechanismus zu Kohlenwasserstoffen. So erhalt man z. B. aus 1-Chlor-hexan 57% d.Th. Hexan, aus l-Chlor-2,2-dimethyl-propan unter Umlagerung 36% d.Th. 2-Methyl-butan bzw. aus 4-Chlor-2,2-dimethyl-butan 50% d.Th. 2,3-Dime-thyl-butans. 

Halogen-allene bilden mit Lithiumalanat je nach Reaktionstemperatur in verschie-denem Verhaltnis Acetylene und deren Reduktionsprodukte5. So erhalt man z. B. aus Brom-allen in Bis-[2-athoxy-athyl]-ather mit 1,2 Mol-Aquivalenten Hydrid bei 100° 9% d.Th. Propin und 37% Propan, bei 25° dagegen 60% d.Th. Propin6 ... 

Data related to the effect of P-halogen on the proton and carbon chemical shifts of CF2H or CF2 groups are scarce (Scheme 4.13), although there is a recent review of 13C spectra of chlorofluorocyclo-propanes.3... 

The preparation of stannylthiazoles via ditin chemistry has not been widely utilized. In one case, the synthesis of 4-tributylstannylthiazole 43 started with selective halogen-metal exchange at C(2) by treating 2,4-dibromothiazole with n-BuLi [33]. Trapping the resulting 2-lithio-4-bromothiazole with propanal and subsequent Jones oxidation secured 4-bromothiazole 42. The Pd-catalyzed reaction of 42 with hexamethyldistannane in the presence of PdCWPhjP provided 4-tributylstannylthiazole 43. 

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