Peroxides from hydrocarbons

Emission from dimols of singlet oxygen may be detected by photomultipliers used for measurement of chemiluminescence from hydrocarbon polymers with a maximum spectral sensitivity at 460 nm. The above scheme, however, requires the presence of at least one molecule of hydrogen peroxide in close vicinity to the two recombining peroxyl radicals and assumes a large heterogeneity of the oxidation process. 

The contactor finds extensive use where high performance phase separation and countercurrent extraction or washing in the one unit are required. Particularly important applications are the removal of acid sludges from hydrocarbons, shown in Figure 13.40, hydrogen peroxide extraction, sulphonate soap and antibiotics extraction, the extraction of rare earths such as uranium and vanadium from leach liquors, and the washing of refined edible oils. 

Di(m-cblorobenzoyl) Peroxide, crysts (from hydrocarbon solvs), mp 123° dec was prepd by reaction 3 chlorobenzoyl chloride in dry toluene with an excess of aq Na2 2 (Ref 4) Di(p chlorobenzoyl) Peroxide, crysts (from CS2), mp 142°dec explodes in a steel bomb when heated to 180° giving 4-4 -dichlorodiphenyl,... 

All these data are in favor of a homolytic mode of oxygen transfer from Vv alkyl peroxides to hydrocarbons, and the mechanism suggested in Scheme 4, based on that of oxidation by Vv-peroxo complexes (Scheme 2), was tentatively attributed to a biradical V17 — OR—O species which can add to arenes and abstract hydrogen atoms from alkanes. It is probable that the absence of a releasable coordination site adjacent to the triangular alkyl peroxide group in (22) precludes the possibility of the alkene coordination to the metal and therefore prevents its heterolytic epoxi-dation. 

In particular, crude polymerizates prepared in the presence of AIBN as initiator, which yield resonance stabilized radicals (17) that are unable to extract hydrogen from hydrocarbon supports (I, 18) show the same content of non-extractable rubber as that of the polymerizates prepared in the presence of active radicals in the hydrogen extraction from hydrocarbon polymers, such as those derived from the decomposition of benzoyl peroxide. 

The peroxidative reactions were mediated and sustained by Cu(II) ions in the light. Table IV shows that fatty acids with at least 2 double bonds are necessary for hydrocarbon formation. As Anacystis lacks those fatty acids, no peroxidative volatile hydrocarbons were produced. Spirulina exclusively contains CO-6 fatty acids as endogenous polyunsaturated fatty acids and evolved Cs hydrocarbons only. The third species, Anabaena, whose thylakoids contain co-3 and Co-6 polyunsaturated fatty acids formed C2 and C5 hydrocarbons simultaneously. We conclude that co-3 polyunsaturated fatty acids are the source of ethane and ethylene and that the CO-6 polyunsaturated fatty acids are the source of pentane and pentene in herbicide-induced peroxidation reactions. Furthermore, we obtained evidence that the propane measured with Bumilleriopsis after an 18-h treatment with either 10 >iM oxyfluorfen or 50 jxM Cu(II) originates from a CO-4 polyunsaturated fatty acid. We have recently isolated and identified this acid as 16 3CO4 (Sandmann, Lambert, B5ger in preparation). 

IRONdlHNDUCED GENERATION OF HYDROGEN PEROXIDE FROM DIOXYGEN INDUCTION OF FENTON CHEMISTRY AND THE ACTIVATION OF O2 FOR THE KETONIZATION OF HYDROCARBONS ... 

A special feature of the autoignition of many organic solvent vapours, including those from hydrocarbons, alcohols, ethers, aldehydes and acids is their ability to form cool flames at temperatures well below their autoignition temperature as measured in the standard apparatus [10]. A cool flame is a form of incomplete combustion, usually involving the formation of an unstable peroxide and its decomposition to an aldehyde. Cool flames emit a pale blue light which is visible only in the dark and on their own produce a relatively modest ca. 20-50 K) temperature rise, hence their name. The main hazard with cool flames lies in their potential for transition into true combustion, and that their products are often less stable and more reactive than the original compound. 

The oxygen transfer reactions from d metal peroxides to hydrocarbons have been reviewed [18]. 

Fig. 3.41 Kinetics of radical degradation resulting from pulverizing in a vibrating ball mill for sulfur and peroxide vulcanizates of SKMS 30 ARKM-15 (oil-extended styrene-a-methyl-styrene) rubbers at 80°K (each test specimen treated for 20 min) (1) peroxide (2) hydrocarbon (3) poly sulfide radicals [40].

In one method of production via petrochemical means, n-butenes can be separated by distillation from hydrocarbons. Treatment with hydrogen peroxide converts butanes such as 1-butene or 2-butene to their epoxide. A glycol such as 2,3-BD is then derived from the epoxide of 2-butene (Szmant 1989). 

The rate of peroxidation of hydrocarbon polymers in the absence of added initiators increases by two orders of magnitude, from the relatively stable unbranched polyethylenes through branched polypropylene to the polyunsaturated rubbers [11] ... 

Sulphonyl Peroxides.—Continuing interest in this class of compound is a consequence of their value in aromatic sulphonoxylation and in their addition to alkenes to give sulphonate esters. A useful electrochemical preparation of bis(methanesulphonyl) peroxide from sodium methanesulphonate makes available a reagent for the synthesis of methanesulphonates of less reactive aromatic hydrocarbons. 

Butane-Naphtha Catalytic Liquid-Phase Oxidation. Direct Hquid-phase oxidation ofbutane and/or naphtha [8030-30-6] was once the most favored worldwide route to acetic acid because of the low cost of these hydrocarbons. Butane [106-97-8] in the presence of metallic ions, eg, cobalt, chromium, or manganese, undergoes simple air oxidation in acetic acid solvent (48). The peroxidic intermediates are decomposed by high temperature, by mechanical agitation, and by action of the metallic catalysts, to form acetic acid and a comparatively small suite of other compounds (49). Ethyl acetate and butanone are produced, and the process can be altered to provide larger quantities of these valuable materials. Ethanol is thought to be an important intermediate (50) acetone forms through a minor pathway from isobutane present in the hydrocarbon feed. Formic acid, propionic acid, and minor quantities of butyric acid are also formed. 

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