W-Alkane

Zenitz obtained the analogous compounds 237 and 238 by the action of the corresponding a-cyano-w-bromo-w-alkanes on 2-methylindolyl magnesium bromide in ether. Eiter and Svierak prepared a-(3-indolyl)propionitrile (239) by the action of a-bromopropionitrile on indole magnesium iodide in anisole. ... 

Cracking of w-alkanes is effectively inhibited by metallic sodium and potassium hydroxide with ABC carrier even under pressure and over a long period of time (Table 2). 

One of the more recent innovative approaches was to look for new micro-organisms and novel carbohydrate substrates. The early fermentations used sugar beet or cane molasses, various syrups, sweet potato starch or glucose itself and the micro-organism was always an Aspergillus spp. In the early 1930 s it was found that yeasts would produce dtric add from acetate. Since then a variety of yeasts, prindpally Candida spp., has been shown to convert glucose, w-alkanes or ethanol to dtric add with great effidency. 

Common names of the compounds arc used throughout this volume. Preparations appear in the alphabetical order of common names of the compound or names of the synthetic procedures. The Chemical Abstracts indexing name for each title compound, if it differs from the common name, is given as a subtitle. Because of the major shift to new systematic nomenclature adopted by Chemical Abstracts in 1972, many common names used in the text are immediately followed by the bracketed, new names. Whenever two names are concurrently in use, the correct Chemical Abstracts name is adopted. The prefix n- is deleted from w-alkanes and w-alkyls. In the case of amines, both the common and systematic names are used, depending on which one the Editor-in-Chief feels is more appropriate. All reported dimensions are now expressed in Systeme International units. 

C2-C4 w-alkanes [42,43], and in supercritical carbon dioxide when employing novel surfactants with fluorocarbon tails [38,44], There is also interest in the further employment of lipids (triglycerides and wax esters, such as isopropyl myristate) as solvent to improve biocompatibility [45],... 

Sugiyama, T., Takeuchi, T., Suzuki, Y. (1975) Thermodynamic properties of solute molecules at infinite dilution determined by gas-liquid chromatography. I. Intermolecular energies of w-alkane solutes in C28 - C36 w-alkane solvents. J. Chromatogr. 105,265-272. 

Gutsche, B., Knapp, H. (1982) Isothermal measurements of vapor-liquid equilibria for three w-alkane-chloroalkane mixtures. Fluid Phase Equil. 8, 285-300. 

Hemandez JE, Machado LT, Corbella R, et al. 1995. w-Alkanes and polynuclear aromatic hydrocarbons in fresh-frozen and pre-cooked-lfozen mussels. Bull Environ Contain Toxicol 55 461-468. 

Figure 8.4 Typical total ion count (TIC) of a bitumen extract from the exterior surface of an archaeological shard obtained by GC-MS. IS = internal standard (C34 w-alkane). This is identical to the output of a GC.

Figure 8.6 Mass spectrum of C34 w-alkane (C34H70). The complete molecule appears at M = 478 and various fragment ions (m/z = 57, 71, etc.) at lower masses. The fragmentation pattern is shown on the molecular structure.

Yang et al. [2] have compared sorbent trapping with solvent trapping after the supercritical fluid extraction of volatile petroleum hydrocarbons in soil. Sorbent trapping yielded quantitative collections of n-alkanes as volatile as n-hexane, while solvent trapping effectively collected w-alkanes as volatile as n-octane. 

Four other significant homologous series present are gem-6 y substituted w-alkanes. The gem prefix designates geminal-substituted compounds, i.e. two substituents on the same atom of a disubstituted compound. Several research groups have reported the presence of 5,5-diethylalkanes, as well as lesser amounts of other g zw-dialkylalkanes, in sedimentary rocks back to the Precambrian and in hydrothermal fluids. 

Fig. 13. Salient features of the GC-MS data for the saturated fraction of a hydrothermal bitumen sam pie from the Mid-Atlantic Ridge (a) TIC - background trace, (b) ra/z 85 fragmentogram (key ion for 3-ethyl-3-methylalkanes and -alkanes), (c) mjz 99, key ion for 3,3-diethylalkanes with -alkanes, and (d) m/z 127, key ion for 5,5-diethylalkanes with w-alkanes. (Numbers refer to total carbon number, dots ovet peaks are -alkanes.)... 

Alkanes are among the least reactive classes of compounds they are poor electron acceptors (low electron affinities) as well as donors (high ionization potentials, viz., CH4,12.61 eV C10H22, 9.65 eV). ° The molecular anions of w-alkanes are especially unstable " negative ion yields for simple alkanes are 10" times lower than positive ion yields. Electron attachment results in small fragment ions (CH, CH2, CH3, M-AIkanes can be ionized by electron (MS) or... 

The band resulting from the methylene rocking vibration (p CH2), in which all of the methylene groups rock in phase, appears near 720 cm-1 for straight-chain alkanes of seven or more carbon atoms. This band may appear as a doublet in the spectra of solid samples. In the lower members of the w-alkane series, the band appears at somewhat higher frequencies. 

Peake, E., Hodgson, G. W., Alkanes in Aqueous Systems. I. Explora-... 

However, in the analysis of saturated hydrocarbon mixtures, D has proved to be not only highly sensitive to the presence of rings (like rmol.), but also to ramifications in the molecules. When comparing D and rmo. of paraffinic or naphthenic hydrocarbons with those of corresponding w-alkanes of equal molecular weight (Z)M-aikane and mol.(w-alkane), respectively), it can be stated that... 

Figs. 57 and 58. Diagrams representing specific refraction vs. and specific parachor vs. — based on A.P.I. data of w-alkanes and -alky -cyclohexanes at 20° and 7O°03. ... 

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