Octyl ion

The other octyl ions (I, II, and IV) are similarly converted to the corresponding trimethylpentanes. Because relatively little 2,2,3-trimethyl-... 

For the model 6-aryl-bicycIo[3,2,l]octyl ions a similar equilibrium can be assumed as well ... 

The cl ical bicyclo[2,2,2]octyl ion 159, unlike classical 2-norbomyl ion 6, has a symmetry plane so that products derived from it must be racemic. 

The bicyclo[2,2,2]octyl cation, as shown by calculations, is less stable than the 2-nor-bornyl one both in the gas phase (by about 6 kcal/mole) and in solutions At the same time the angle strain in the 2-norbomyl ion is higher, and the torsional and long-range nonbonded effects are comparable with those for the bicyclo[2,2,2]-octyl ion the difference seems to be due to the norbomyl cation geometry more favourable for a-delocalization as compared with the bicyclo[2,2,2]octyl ion. 

The mechanism involved in the formation of the alkyl ions other than the quasiparent ion is not known with certainty. They may be formed by a direct electrophilic attack on C—C bonding electrons in a process which can be looked upon as a kind of alkide ion displacement reaction. For example, for the formation of the octyl ion from octadecane, one can write... 

Entry 4 shows that reaction of a secondary 2-octyl system with the moderately good nucleophile acetate ion occurs wifii complete inversion. The results cited in entry 5 serve to illustrate the importance of solvation of ion-pair intermediates in reactions of secondary substrates. The data show fiiat partial racemization occurs in aqueous dioxane but that an added nucleophile (azide ion) results in complete inversion, both in the product resulting from reaction with azide ion and in the alcohol resulting from reaction with water. The alcohol of retained configuration is attributed to an intermediate oxonium ion resulting from reaction of the ion pair with the dioxane solvent. This would react until water to give product of retained configuratioiL When azide ion is present, dioxane does not efiTectively conqiete for tiie ion-p intermediate, and all of the alcohol arises from tiie inversion mechanism. ... 

An alternative view of these addition reactions is that the rate-determining step is halide-assisted proton transfer, followed by capture of the carbocation, with or without rearrangement Bromide ion accelerates addition of HBr to 1-, 2-, and 4-octene in 20% trifluoroacetic acid in CH2CI2. In the same system, 3,3-dimethyl-1-butene shows substantial rearrangement Even 1- and 2-octene show some evidence of rearrangement, as detected by hydride shifts. These results can all be accoimted for by a halide-assisted protonation. The key intermediate in this mechanism is an ion sandwich. An estimation of the fate of the 2-octyl cation under these conditions has been made ... 

In the author s group, much lower-melting benzenesulfonate, tosylate, or octyl-sulfate ionic liquids have recently been obtained in combination with imidazolium ions. These systems have been successfully applied as catalyst media for the biphasic, Rh-catalyzed hydroformylation of 1-octene [14]. The catalyst activities obtained with these systems were in all cases equal to or even higher than those found with the commonly used [BMIM][PF6]. Taking into account the much lower costs of the ionic medium, the better hydrolysis stability, and the wider disposal options relating to, for example, an octylsulfate ionic liquid in comparison to [BMIM][PF6], there is no real reason to center future hydroformylation research around hexafluorophosphate ionic liquids. 

Mechanism of the Catalysis of the Bis(N-octyl-2-imidazolyl)-carbinol(38c)-Zn2 + ion and of Related Complexes... 

The reaction of 1-chlorooctane with CH3CO2- to give octyl acetate is greatly accelerated by adding a small quantity of iodide ion. Explain. 

This paper describes a comparison of the extraction behavior of selected. actinide(III), (IV), and (VI) ions by the dihexyl-N, N-diethyl analogs of carbamoylmethyl-phosphonate and phosphinate and octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide. 

As expected, HTMAB made a respectable showing in these experiments. Trioctylmethylammonium chloride (TOMAC) and trioctylmetliylammonium bromide (TOMAB) outperformed all other catalysts. It was postulated that the three octyl groups were the proper length for solvation of the polymer while at the same time small enough to avoid sterically hindering the reaction. In order to determine if TOMAB could be used to catalyze PET depolymerization for more than one treatment cycle, the catalyst was recovered upon completion of one treatment and added to a second run for 60 min. Tetraethylammonium hydroxide (TEAOH) was studied as a catalyst in order to demonstrate the effect of hydroxide ion as a counterion. The percent PET conversion for the second cycle was 85.7% compared to a conversion of 90.4% for the first treatment cycle. 

In an acetone extract from a neoprene/SBR hose compound, Lattimer et al. [92] distinguished dioctylph-thalate (m/z 390), di(r-octyl)diphenylamine (m/z 393), 1,3,5-tris(3,5-di-f-butyl-4-hydroxybenzyl)-isocyanurate m/z 783), hydrocarbon oil and a paraffin wax (numerous molecular ions in the m/z range of 200-500) by means of FD-MS. Since cross-linked rubbers are insoluble, more complex extraction procedures must be carried out (Chapter 2). The method of Dinsmore and Smith [257], or a modification thereof, is normally used. Mass spectrometry (and other analytical techniques) is then used to characterise the various rubber fractions. The mass-spectral identification of numerous antioxidants (hindered phenols and aromatic amines, e.g. phenyl-/ -naphthyl-amine, 6-dodecyl-2,2,4-trimethyl-l,2-dihydroquinoline, butylated bisphenol-A, HPPD, poly-TMDQ, di-(t-octyl)diphenylamine) in rubber extracts by means of direct probe EI-MS with programmed heating, has been reported [252]. The main problem reported consisted of the numerous ions arising from hydrocarbon oil in the recipe. In older work, mass spectrometry has been used to qualitatively identify volatile AOs in sheet samples of SBR and rubber-type vulcanisates after extraction of the polymer with acetone [51,246]. 

BH+(H20)n/BH+(H20)n 1 measured in function of the IN-OR potential are shown in Figure 6A for B = octyl amine and (n/n-1) = (1/0) and (2/1). The ion ratios are found constant as would be expected for thermal ions at equilibrium and following Castleman s61 results. The actual ion intensities, rather than the ratio, are shown in Figure 6B. These increase with increase of the IN-OR potential, an expected result since the ion transport to the orifice plate is improved by the higher drift field. A potential drop of IN-OR = 10 V was selected for the equilibria measurements because it leads to a fair intensity while keeping the ions well in the thermal range. 

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