Isohexanes

Hexane refers to the straight-chain hydrocarbon, C H branched hydrocarbons of the same formula are isohexanes. Hexanes include the branched compounds, 2-methylpentane, 3-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, and the straight-chain compound, / -hexane. Commercial hexane is a narrow-boiling mixture of these compounds with methylcyclopentane, cyclohexane, and benzene (qv) minor amounts of and hydrocarbons also may be present. Hydrocarbons in commercial hexane are found chiefly in straight-mn gasoline which is produced from cmde oil and natural gas Hquids (see Gasoline AND OTHER MOTOR fuels Gas,natural). Smaller volumes occur in certain petroleum refinery streams. 

Chloropropane Isopropyl chloride 199 C,H,Cl 2-Methylpentane Isohexane 24 QHi4... 

LHSV Temp.,°F % Conversion Selectivity to Benzene Selectivity to Isohexane... 

Nonsystematic names for organic compounds may still be found in the chemical literature and chemical supply catalogs, and so it is important to be somewhat familiar with these as well as with the IUPAC rules. Give the systematic name for (a) isobutane and (b) isopentane, (c) Formulate a rule for the usage of the prefix iso- and predict the structure of isohexane. Structures for these compounds can be found on the Web site for this book. 

Figure 9.7. Temperature dependence of p/ -xg3oo and T- c of trons-stilbene in methylcydohexane and isohexane. (Data from Ref. 38 see also Ref. 1.)...

Fig. 12.4. Vapor-to-water transfer data for saturated hydrocarbons as a function of accessible surface area, from [131]. Standard states are 1M ideal gas and solution phases. Linear alkanes (small dots) are labeled by the number of carbons. Cyclic compounds (large dots) are a = cyclooctane, b = cycloheptane, c = cyclopentane, d = cyclohexane, e = methylcyclopentane, f = methylcyclohexane, g = cA-l,2-dimethylcyclohexane. Branched compounds (circles) are h = isobutane, i = neopentane, j = isopentane, k = neohexane, 1 = isohexane, m = 3-methylpentane, n = 2,4-dimethylpentane, o = isooctane, p = 2,2,5-tri-metbylhexane. Adapted with permission from [74], Copyright 1994, American Chemical Society...

Common Name 2-Methylpentane Synonym isohexane Chemical Name 2-methylpentane CAS Registry No 107-83-5... 

Isodurene, t98 Isoeugenol, ml08 Isohexane, m357 Isoleucinol, a211 Isomesityl oxide, m370... 

Table I gives the compositions of alkylates produced with various acidic catalysts. The product distribution is similar for a variety of acidic catalysts, both solid and liquid, and over a wide range of process conditions. Typically, alkylate is a mixture of methyl-branched alkanes with a high content of isooctanes. Almost all the compounds have tertiary carbon atoms only very few have quaternary carbon atoms or are non-branched. Alkylate contains not only the primary products, trimethylpentanes, but also dimethylhexanes, sometimes methylheptanes, and a considerable amount of isopentane, isohexanes, isoheptanes and hydrocarbons with nine or more carbon atoms. The complexity of the product illustrates that no simple and straightforward single-step mechanism is operative rather, the reaction involves a set of parallel and consecutive reaction steps, with the importance of the individual steps differing markedly from one catalyst to another. To arrive at this complex product distribution from two simple molecules such as isobutane and butene, reaction steps such as isomerization, oligomerization, (3-scission, and hydride transfer have to be involved.

Cyclohexane or w-hexane can be used in place of carbon tetrachloride. Technical normal hexane may contain substantial amounts of methylcyclopentane and isohexane that lower the yield through formation of C7-acids that are hard to remove. 

Benzene formation from all isohexanes had a similar energy of activation value. With platinum this was nearly twice as high as that of n-hexane aromatization (62) with palladium black, however, nearly the same values were found for -hexane and isohexanes (97a). This indicates a common rate-determining step for aromatization with skeletal rearrangement. This is not the formation and/or transformation of the C5 ring. We attribute benzene formation to bond shift type isomerization preceding aromatization. It requires one step for methylpentanes and two steps for dimethyl-butanes this is why the latter react with a lower rate, but with the same energy of activation. 

Isocyanatopropane, see Atrazine Isofenphos oxon, see Isofenphos Isoheptane, see PCB-1242 Isohexane, see PCB-1242 Isononane, see PCB-1242 Isononanes, see Octane Isooctane, see PCB-1242 Isooctanes, see Octane Isophthalic acid, see ro-Xylene Isopropoxyphenol, see ProDoxnr Isopropyl alcohol, see Isopropyl acetate Isopropylatnide, see Bentazone IV-Isopropylaniline, see Propachlor Isopropylbenzene, see Propylbenzene, PCB-1242,... 

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