Alkanes, addition

Occasionally, the reactivity of ions with differing coordination numbers may be compared. Laser ablation of Mo02 or M0O3 produced the ions Mo+, [MoO]+, and [Mo02]+, which were reacted with alkanes, alkenes, and C6 hydrocarbons (183). None of the ions reacted with methane and Mo+ was generally less reactive than the other ions with the alkanes. Additions of the alkane to the Mo+, [MoO]+, and [Mo02]+ with loss of H2 or 2H2 were the major reaction products. 

Probtem 6.38 Suggest a mechanism for alkane addition where the key step is an intermolecular hydride (H ) transfer. <... 

It is important to use dry air and dry equipment because difluorotris(perfluoroalkyl)-25-phos-phanes react very rapidly with water to form tris(perfluoroalkyl)phosphane oxides. Under these conditions, the electrochemical perfiuorination of triethyl-, tripropyl-, and tributylphosphanc oxides yields 15-50% of the corresponding difluorotris(perfluoroalkyl)-A5-phosphanes. A decrease in yield is observed with a longer carbon chain (chain with 2C atoms 42%, with 6C atoms 24 %).63 Byproducts are perfluorinated alkanes. Addition of bromine makes it possible to electrochemically fluorinate trialkylphosphane oxides with a carbon chain length of C5 to... 

Catalytic reforming has become the most important process for the preparation of aromatics. The two major transformations that lead to aromatics are dehydrogenation of cyclohexanes and dehydrocyclization of alkanes. Additionally, isomerization of other cycloalkanes followed by dehydrogenation (dehydroisomerization) also contributes to aromatic formation. The catalysts that are able to perform these reactions are metal oxides (molybdena, chromia, alumina), noble metals, and zeolites. 

To name branched alkanes, additional steps to name the branching group and locate it on the root chain are needed. 

Hydrogen adds to an alkyne in the presence of a metal catalyst (Pd, Pt, or Ni) to form an alkane. Addition of hydrogen to an internal alkyne in the presence of Lindlar cat-... 

A soluble dendritic Ni catalyst for the atom-transfer radical addition (ATRA, i.e., polyhalogenated alkane addition to olefins, the Kharasch addition) was described by van Leeuwen and van Koten et al. in 1994 [17]. GO and G1 carbosilane den-drimers, fimctionalized with NGN pincer-nickel(II) groups, were synthesized and applied as homogeneous catalysts for the addihon of organic halides to alkenes [Eq. (7)]. 

SDS, hexadecyltratnethylammoniiim chloride (CTAC), andBrij 35 mobile phases, for two neutral test solutes, benzene and 2-ethylanthraquinone, retained on a CIS stationary phase [17]. The test solutes were chosen due to the fact that benzene is relatively water soluble and 2-ethylanthraquinone is virtually water insoluble. Thus, they represent two extremes in hydrophobicity. The results indicated that the presence of alcohols, diols, alkylnitriles, and dipolar aprotic solvents, in the micellar mobile phases, resulted in a diminution of the retention factors for the two test solutes. In contrast, the presence of the alkane additives i.e., pentane, hexane, cyclohexane) did not greatly alter the retention. 

Proton abstraction occurs mostly with compounds of low proton affinity e.g. alkanes. Addition reactions between functional groups and the reagent gas can also be observed. The extent of this reaction depends on the temperature, pressure and concentration conditions in the ion chamber. 

Alkenes react with H2 in the presence of a metal catalyst such as palladium or platinum to yield the corresponding saturated alkane addition products. We describe the result by saying that the double bond has been hydrogenated, or reduced. Note that the word reduction is used somewhat differently... 

The mechanism of influence of NO2 on the oxidation and spontaneous combustion of hydrocarbons, primarily at low pressures, was discussed in detail in [13]. For the slow oxidation of methane, as in the case of other alkanes, addition of NO2 was demonstrated to shorten or even eliminate (starting from a certain amount) the induction period, causing no changes in the qualitative and quantitative composition of the oxidation products. For the oxidation of a 15% CH4—85% air mixture at T = 480—510 °C and P = 300 Torr in the presence of a small (1.37%) NO2 additive, the heat-release curve featured two peaks [175], the first of which, according to the authors, is associated with the formation of formaldehyde, whereas the second, with its decomposition. This explanation is difficult to accept, because in the absence of NO2, the formation and decomposition of formaldehyde also occur, but no double peak is observed. A double exothermic peak in the oxidation of methane in the presence of NO2 was observed in [176] and for the oxidation of propane in [177]. 

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