Oxygenation/hydroxylation

Overall the reaction is classified as an addition Water adds to the carbonyl group Hydrogen becomes bonded to the negatively polarized carbonyl oxygen hydroxyl to the positively polarized carbon... 

Oxygen Compounds. Although hydrogen peroxide is unreactive toward ozone at room temperature, hydroperoxyl ion reacts rapidly (39). The ozonide ion, after protonation, decomposes to hydroxyl radicals and oxygen. Hydroxyl ions react at a moderate rate with ozone (k = 70). 

Fig. 1. Diagrammatic representation of the succession of layers in some layer lattice siHcates (12) where 0 is oxygen , hydroxyl , siHcon o. Si—Al aluminum C, Al—Mg O, potassium , Na—Ca. Sample layers are designated as O, octahedral T, tetrahedral and B/G, bmcite- or gibbsitelike. The...

O , OH and V stand for reactive oxygen, hydroxyl species and anionic vacancies from the support, respectively. 

In the presence of trace amounts of iron, superoxide can then reduce Fe3+ to molecular oxygen and Fe2+. The sum of this reaction (13.2) plus the Fenton reaction (13.1) produces molecular oxygen, hydroxyl radical and hydroxyl anion from superoxide and hydrogen peroxide, in the presence of catalytic amounts of iron. This is the Haber-Weiss reaction (13.3), originally described by Haber and Weiss (1934), but manifestly impossible from thermodynamical considerations in the absence of catalytic amounts of redox metals such as iron and copper ... 

Figure 8. Water oxygen-hydroxyl oxygen 06 pair distribution function, calculated from a molecular dynamics simulation of a-D-glucopyranose in aqueous solution. (Reproduced from Ref. 32. Copyright 1989 American Chemical Society.)...

FIGURE 7.26 Idealized structure of the layers in a smectite clay (a) showing only the oxygen/hydroxyl framework (b) also depicting aluminium and silicon positions. 

O oxygen O hydroxyl group O water molecule 0 oxygen + hydroxyl (in projection)... 

Hart (1952, 1954) studied the oxidation of formic acid by the radiolysis method. In the presence of oxygen, hydroxyl radicals abstract hydrogen from HCOzH. Both the carboxyl radicals and formyl radicals are formed. These radicals undergo oxygen addition and subsequently dissociate ... 

Silicon Magnesium O Oxygen Hydroxyle Crystallization Water... 

O Oxygens Hydroxyls Aluminium, iron, magnesium o and Silicon, occasionally aluminium... 

Another subgroup of the 2His-lcarboxylate family is dependent on a reduced pterin cofactor (5). They catalyze hydrox-ylations at the aromatic positions of amino acids in phenylalanine catabolism and hormone biosynthesis (Fig. 2). Unlike the a-KG-dependent enzymes, the pterin co-substrate does not ligate to the iron directly. In the reaction cycle, the pterin cosubstrate supplies two electrons for the heteiolysis of O2 to give a yet to be characterized iron-oxygen hydroxylating species. 

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