Ethane ions, decomposition

The information on the characteristic ion decomposition times t < 10 s is rather limited. Experiments using ionization of complex molecules by electron impact in a relatively strong electric field [214] show that most ions in the mass spectra of ethylene, ethane, and hexane are formed in less than 10 s. However, fragment ions formed in a time > 10 s are observed in the mass spectra of hexane and toluene in considerable amounts. The characteristic decomposition times of and other ions [214, 461] include ... 

Chloroform in aqueous solutions at concentrations ranging from 1 to 10% of the solubility limit were subjected to y rays. At a given radiation dose, as the concentration of the solution decreased, the rate of decomposition increased. As the radiation dose and solute concentration were increased, the concentrations of the following degradation products also increased methane, ethane, carbon dioxide, hydrogen, and chloride ions. Conversely, the concentration of oxygen decreased with increased radiation dose and solute concentration (Wu et al, 2002). 

The fragmentation patterns of a number of phosphine-metal carbonyl complexes have been reported 164). Complexes of bis(diphenylphos-phino)ethane (diphos) appear to lose ethylene to give ions of the type (Ph2P)2Mo+. In contrast to thermal decomposition by loss of phosphine,... 

Ion lifetimes of the order of nanoseconds have also been measured in experiments which confined the detectable ionization to the region of a filament stretched along the axis of a cylinder [468, 469, 470, 815]. Electron impact ionization was employed and decomposition occurred within the strong field between filament and cylinder. Ethylene, ethane and hexane were among molecules studied. 

An intramolecular isotope effect of 7( = /CHCH //ch3cd3) has been found for the loss of ethane from the decomposition of the metastable 3-hydroxypentane ion [CD3CH2CH(OH)CH2CH3]t [363]. The isotope... 

It is possible that some acetate radicals are formed by the direct discharge of the ions as, it will be seen shortly, is the case in non-aqueous solutions but an additional mechanism must be introduced, such as the one proposed above, to account for the influence of electrode material, catalysts for hydrogen peroxide decomposition, etc. It is significant that the anodes at which there is no Kolbe reaction consist of substances that are either themselves catalysts, or which become oxidized to compounds that are catalysts, for hydrogen peroxide decomposition. By diverting the hydroxyl radicals or the peroxide into an alternative path, viz., oxygen evolution, the efficiency of ethane formation is diminished. Under these conditions, as well as when access of acetate ions to the anode is prevented by the presence of foreign anions, the reactions mentioned above presumably do not occur, but instead peracetic acid is probably formed, thus,... 

The effect of electrical fields on the radiolysis of ethane has been examined by Ausloos et and this study has shown that excited molecules contribute a great deal to the products. The experiments were conducted in the presence of nitric oxide, and free-radical reactions were therefore suppressed. The importance of reactions (12)-(14) was clearly demonstrated by the use of various isotopic mixtures. Propane is formed exclusively by the insertion of CH2 into C2H6 and the yield is nearly equal to the yield of molecular methane from reaction (14). Acetylene is formed from a neutral excited ethane, probably via a hot ethylidene radical. Butene and a fraction of the propene arise from ion precursors while n-butane appears to be formed both by ionic reactions and by the combination of ethyl radicals. The decomposition of excited ethane to give methyl radicals, reaction (15), has been shown by Yang and Gant °° to be relatively unimportant. The importance of molecular hydrogen elimination has been shown in several studies ° °. ... 

The rare-gas sensitized radiolysis of propane has been studied in the gas phase and in the liquid phase". Charge transfer from the rare-gas ion to propane is followed by ionic reactions. In particular, the decomposition of C3H8 to give CH4 by reaction (4) is important, as is the ion-molecule reaction of C2H5 with propane to give ethane by reaction (7). 

Preliminary results with a manganese-substituted Keggin ion catalyst that has an extremely stable PWi 1039 - backbone (Figure 1), shows some promise with small hydrocarbons(l). This catalyst can be heated to 65 °C for long periods without decomposition. An initial experiment with ethane and t-butyl hydroperoxide in benzene gave 2 turnovers of ethane to ethanol in three hr at 65 °C, while with propane the turnover number was 24 and provided isopropanol and n-propanol in a 5 1 ratio (Table m). 

Kinetics of decomposition at short times (methyl radical from the n-butane [825], 2, 2-dimethylbutane [240] and 2, 2-dimethylpentane [240] ions, loss of ethyl from n-heptane, n-hexane and n-octane ions [522, 825], loss of methane from the neopentane ion [825], and loss of ethane from the 3-ethylpentane ion... 

The radiolysis product yields in the presence of ion scavenger (Table III) also show that ethane is not formed from neutralization of stable ions. Therefore, the remainder of the ethane product (above that indicated to result from neutral decomposition) must be produced by an ion-molecule process—i.e., a yield of G = 1.47. The ion-molecule reactions previously listed show that ethylene ions react with ethyl chloride to form ethane. From the relative rates indicated for Reactions 3a-3d and the ethane yield just derived, a relative yield of 2.46 may be deduced for the ionic fragmentation to ethylene ion in the radiolysis. 

As typified by the ethanolysis of (CH3)2Pd(PEt3)2, many solvolyses of metal-carbon bonds are found to be quite complex when studied in detail. Even the generalization that the C—M bond hydrolyzes to give alkane and metal ion is not universally valid. Schrauzer and Windgassen (23) found that a methylcobalt compound with dimethylglyoxime ligands gave methane and methyl chloride in a 3 1 ratio on treatment with hot concentrated hydrochloric acid. Traces of ethane also formed, apparently by thermal decomposition with formation of methyl radicals. Warm concentrated KOH solution decomposed this complex with formation of methane. 

In the course of study of the reaction of NO with aromatic amines, the effect of solvents on the reaction mechanism has been established. NO reacts in ethereal solvents (tetrahydrofuran (THF), dioxane, ethoxy ethane (EtOEt), dimethylether (DME)) or chloroform to give deamination products [33]. This solvent effect was explained by the competitive decomposition of diazonium ions via accepting an electron from NO to give the phenyl radical, and hydrogen (H)-atom abstraction from the solvent leads to the deamination product ... 

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