Formation of oxygenated products

It is possible that H02 reacts with alkyl radicals, but it cannot be the sole reaction responsible for the formation of oxygenated products during the pic darret since the H02 radical concentration becomes very high at 450°-500°C., while the pic darret disappears (Figure 4). 

H. Berger (Koninklijke/Shell Laboratorium, Amsterdam) Concerning the effect of cyanides on metal catalysis (deactivation and formation of oxygenated products), what are your arguments against the explanation that the metal ion becomes completely inactive, while the products arise from a mechanism analogous to that proposed by Berger [Rec. Trav. Chim. 82, 733 (1963)] for the oxidation in tert-butyl alcohol with excess mercaptan relative to base, Did you check that no hydrolysis of disulfide occurs in the presence of cyanide ... 

Formation of oxygenated products over nitrided iron catalysts 6I ] ... 

The carbide mechanism fails, however, to explain the formation of oxygenated products such as alcohols, aldehydes and acids which are common sidc-products in FT synthesis and are especially formed in the first stage of the rcaclion [159]. Assumption of CO insertion as the terminating step to produce oxygenated products would be a viable explanation. Such a scheme has been proposed by Ichikawa to account for the formation of oxygenated Cj products over rhodium (Equation (29)) [149]. 

In trying to confirm their theory in regard to the intermediate formation of oxygenated products during combustion, Bone 9 and his co-workers carried out extensive researches and from their work has come the present hydroxylation theory. According to Bone the oxidation of methane takes place in steps, methanol, formaldehyde, formic acid, and carbonic acid being formed in the order named. These various steps are indicated below. The double arrows point out the mam course of reaction, while the single arrows show how the intermediate compounds may decompose. 

The results of this preliminary study have shown that the introduction of a carbon-carbon double bond into an alcohol reagent can lead to the formation of oxygenate products in high selectivity and this may be of significance for the use of zeolites for the synthesis of fine chemicals. 

The iso-synthesis produces hydrocarbons, as has been proved, over a primary formation of oxygenated products and a secondary dehydration to olefins. 

We see that the overall result of hydroxyl radical attack on ethene is conversion of two molecules of NO to N02, formation of 1.44 molecules of formaldehyde and 0.28 molecules of glycol aldehyde (HOCH2CHO), and regeneration of a hydroxyl radical. By comparing this mechanism to that of propane, we see the similarities in the NO to N02 conversion and the formation of oxygenated products. 

Photolysis of alkanes in air gives rise to the formation of oxygenated products in very low yields. Thus irradiated with high-pressure mercury arc, cyclohexane saturated with air ([0 1 = 1.9 x 10 mot dm ) yields cyclohexanol, cyclohexanone and cyclohexyl hydroperoxide (ratio 1.0 0.6 0.9) [37a], Under analogous conditions, toluene is transformed into the mixture of benzaldehyde and benzyl alcohol (after 24 h the total yield 0.15 %, ratio aldehyde/alcohol is 3 1) [37b]. Benzyl hydroperoxide is the initial product of this reaction which decomposes further to yield more stable oxygenates [37c]. 

Figure 5. Modeling the Fischer-Tropsch reaction on tetranuclear iron clusters. Formation of oxygenated products is not shown.

What Heterogeneous Catalysts are Active in Formation of Oxygenated Products ... 

Formation of Oxygenated Products from Synthesis Gas and ligand-stabilized formyl compounds (3), (4) of Ta ... 

Two very curious but heretofore unexplained phenomena relate to the interaction of reduced polyoxometalates with O2 and are addressed by our experiments described right below. The first involves the lack of oxygenated products seen in the photochemical functionalization of heptacyclotetradecane (HCTD) in the presence of O2 by Christina Prosser-McCartha. The second involves two observations by Neumann and Levin, namely, the suppression of tetralin autoxidation and the clean conversion of a-terpinene to p-cymene in the presence of O2 without formation of oxygenated products. 

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