Hydrocarbons and Derivatives

For many years it was assumed that the long-chain hydrocarbons found in plant waxes were formed by a head-to-head condensation of two fatty acids with the decarboxylation of one acid to yield a mid-chain ketone, which would subsequently be reduced, dehydrated, and reduced to yield the final hydrocarbon. Experiments with specifically and doubly labeled and Cig acids showed that the entire carbon chain of the acids was incorporated without decarboxylation into C29 and C31 hydrocarbons in B, oleracea and in Spinacea oleracea (220, 224). Cig fatty acid was found to be incorporated more rapidly than C16 acid into C29 alkane (220), and the carbonyl carbon of nonacosane-15-one was shown to be derived from C-2 and C-4 of exogenous C16 and C13 acids, respectively (246, 247). Such experimental evidence ruled out the head-to-head condensation mechanism. 

The mechanism of conversion of fatty acids to alkanes remained elusive until recently. Cell-free preparations generated alkanes from n-Cn, 1-C24, and 

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If the thermodynamic data for a compound of interest have not been determined and abulated, it may be possible to estimate AHf or AGj from tabulated data pertaining to dividual structural units. Procedures have been developed for estimating thermodynamic characteristics of hydrocarbons and derivatives by summing the contributions of the constituent groups. The group increments are derived from experimental thermochemical iata and therefore depend on the existence of reliable data for the class of compounds of merest. 

Hydrocarbons and derivatives (n-paraffins, ethanol) As carbon source NHs, NH4+... 

Table 5.8A. Triplet Lifetimes of Aromatic Hydrocarbons and Derivatives...

Such xenobiotics as aliphatic hydrocarbons and derivatives, chlorinated ahphatic compounds (methyl, ethyl, methylene, and ethylene chlorides), aromatic hydrocarbons and derivatives (benzene, toluene, phthalate, ethylbenzene, xylenes, and phenol), polycyclic aromatic hydrocarbons, halogenated aromatic compounds (chlorophenols, polychlorinated biphenyls, dioxins and relatives, DDT and relatives), AZO dyes, compounds with nitrogroups (explosive-contaminated waste and herbicides), and organophosphate wastes can be treated effectively by aerobic microorganisms. 

Table VI summarizes half-wave potentials of cathodic waves. These values are linearly dependent on the energies of lowest free 7r-molecular orbitals. The correlation is just about as close (Table IV) as those for analogous quantities with benzenoid and other hydrocarbons and derivatives of benzenoid hydrocarbons.

Long-chain aliphatic hydrocarbons and derivatives originating in living cells. Some lipids, such as fatty acids, are also surfactants. Simple lipids tend to be hydrocarbon-soluble but not water-soluble. Examples fatty acids, fats, waxes. 

In Chapter 16 Trabalon and Bagneres present an overview of non-insect contact pheromones with emphasis on long-chain hydrocarbons and derivative compounds in Arachnids. Apart from studies on spider and scorpion venoms, the first semiochemical studies in these... 

A novel methodology for preparative aromatic nitration in which nitrogen dioxide acts a good nitrating agent for aromatic hydrocarbons and derivatives in the presence of ozone ( kyodai nitration) [362] has been applied for azoles [363] (Scheme 44). 

Anionic nucleophiles provide valuable and versatile routes for the preparation of C-glycosides. However, the most extensively used technologies lie within the chemistry of Lewis acid-mediated reactions of carbohydrates with unsaturated hydrocarbons and derivatives thereof. In the next series of examples, reactions of sugars and sugar derivatives with olefins and their silyl-, stannyl-, and aluminum derivatives are discussed. 

Simon, Z., Baiaban, A.T., Ciubotariu, D. and Balaban, T.-S. (1985a). QSAR for Carcinogenesis by Polycyclic Aromatic Hydrocarbons and Derivatives in Terms of Delocalization Energy, Minimal Sterical Differences and Topological Indices. Rev.Roum.Chim.,30,985-1000. 

Petroleum chemicals are synthetic organic chemicals including hydrocarbons and derivatives containing oxygen, nitrogen, sulfur, the halogens, synthesized from fractions of crude petroleum or natural gas hydrocarbon components (70). 

The partition coefficients of aromatic hydrocarbons and derivatives are presented in Table 6.5. If we compare data with aliphatic hydrocarbons containing the same number of carbon atoms, the partition coefficients of the aromatic compounds are significantly lower, as expected from their respective solubilities in water. It also appears that the partitioning of aromatic compounds is more dependent on the surfactant headgroup than the aliphatic, but data are scarce and few comparisons can be made. 

Partition Coefficients of Aromatic Hydrocarbons and Derivatives in Aqueous Surfactant Solutions at 298.15 K... 

J. Schulze and M. Homann, C4-hydrocarbons and derivatives. Springer, Berlin, 1989. 

For hydrocarbons and derivatives, the increase of conductivity varied widely as a function of physical phase (melted or powdered) in a range 102 to 10° higher. A decrease of energy activation with increasing molecular weight (2.2-1.2 e.v.) was noted. 

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