Saturated hydrocarbons, distributions

The saturated hydrocarbon distributions of the marl samples are dominated by long-chain n-alkanes of higher land plant origin (21) with a strong odd-over-even carbon number predominance. Hopanoid hydrocarbons are the next most abundant constituents, but other hydrocarbons particularly abundant in the laminite samples described hereafter are also clearly recognizable. 

The solvent triangle classification method of Snyder Is the most cosDBon approach to solvent characterization used by chromatographers (510,517). The solvent polarity index, P, and solvent selectivity factors, X), which characterize the relative importemce of orientation and proton donor/acceptor interactions to the total polarity, were based on Rohrscbneider s compilation of experimental gas-liquid distribution constants for a number of test solutes in 75 common, volatile solvents. Snyder chose the solutes nitromethane, ethanol and dloxane as probes for a solvent s capacity for orientation, proton acceptor and proton donor capacity, respectively. The influence of solute molecular size, solute/solvent dispersion interactions, and solute/solvent induction interactions as a result of solvent polarizability were subtracted from the experimental distribution constants first multiplying the experimental distribution constant by the solvent molar volume and thm referencing this quantity to the value calculated for a hypothetical n-alkane with a molar volume identical to the test solute. Each value was then corrected empirically to give a value of zero for the polar distribution constant of the test solutes for saturated hydrocarbon solvents. These residual, values were supposed to arise from inductive and... 

Chipot C, Angyan JG, Ferenczy GG, Scheraga HA (1993) Transferable net atomic charges from a distributed multipole analysis for the description of electrostatic properties — a case-study of saturated-hydrocarbons. J Phys Chem 97(25) 6628—6636... 

Considerable interest in the subject of C-H bond activation at transition-metal centers has developed in the past several years (2), stimulated by the observation that even saturated hydrocarbons can react with little or no activation energy under appropriate conditions. Interestingly, gas phase studies of the reactions of saturated hydrocarbons at transition-metal centers were reported as early as 1973 (3). More recently, ion cyclotron resonance and ion beam experiments have provided many examples of the activation of both C-H and C-C bonds of alkanes by transition-metal ions in the gas phase (4). These gas phase studies have provided a plethora of highly speculative reaction mechanisms. Conventional mechanistic probes, such as isotopic labeling, have served mainly to indicate the complexity of "simple" processes such as the dehydrogenation of alkanes (5). More sophisticated techniques, such as multiphoton infrared laser activation (6) and the determination of kinetic energy release distributions (7), have revealed important features of the potential energy surfaces associated with the reactions of small molecules at transition metal centers. 

These adducts are more active than the iron ones in the conversion of syngas. At 250°C, a higher yield of methane is observed (Table U) and carbon dioxide is produced in smaller amounts. Inspection of Table 5 summarizing the influence of the H2/CO ratio on products selectivity also indicates a higher production of saturated hydrocarbons. This behavior is typical for cobalt catalysts in F-T synthesis (j2,25). The chain-length distribution is similar to that observed for catalysts derived... 

Bituminous Substances. The distribution of hydrocarbons and other bitumens in some of the Paleozoic rocks of the area is shown in Tables I and II, the latter summarized after Swain (7). The presumed saturated hydrocarbons of the Ordovician, Silurian and Lower Devonian samples are measurably less than in the Middle and Upper Devonian samples. The presumed aromatic hydrocarbons are not as well differentiated. The pyridine-plus-methanol-eluted chromatographic fractions, arbitrarily taken as asphaltic material, also appear, like the aromatic fractions, to be controlled more by local variations than by geologic age. 

SimSim fills the gap between material balance techniques and complex reservoir simulation yet keeping the simplicity and speed of the material balance but providing reservoir simulation like results, i.e. pressure, saturation, hydrocarbons in place and fluid flux distribution within the reservoir. 

The OH product rotational distributions from the reactions of 0 (1D) with saturated hydrocarbons [CH4, C2H6, C3H8 and C(CH3)4] are observed to have a bimodal structure [474]. The population of the lowest rotational levels corresponds to an insertion mechanism in which the O atom approaches the R—H perpendicularly. The higher rotational levels correspond to production of OH by abstraction following a collinear... 

The ability of the Fe (DPAH)2/02/PhNHNHPh system (where PhNHNHPh is a mimic for flavin rednctases) to monooxygenate saturated hydrocarbons closely parallels the chemistry of the methane monooxygenase proteins. However, the enzyme oxygenates 2-Me-bntane with an isomer distribution of 82% primary alcohol, 10% secondary, and 8% tertiary. The present model gives a distribution of 21% primary, 29% secondary, and 50% tertiary. Clearly the protein affords a cavity that is selective for -CH3 groups. 

Halogenation of saturated hydrocarbon polymers can hardly be controlled and is frequently assodated with chain degradation phenomena In contrast, the presence of randomly distributed olefinic unsaturations, allows selective halogenation reactions by adopting appropriate conditions. For instance, butyl rubber can be chiorinated or brominated in allylic positions and chloro-butyl or bromo-butyl rubber results The latter polymers are very interesting since they exhibit fast curing rates when sulfur and ZnO are introduced in the formulations. 

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