Alcohol dissociation

Since the peroxyl radicals derived from alcohol dissociate to a carbonyl compound and H02 (see Chapter 8), two reactions in which the aminyl radicals formed from amine are reduced, occur in parallel under the conditions of the alcohol oxidation ... 

This mechanism, accounting for the observed pH perturbations, does not directly consider the proton charge relay system involving Ser-48 and His-51. However it is probable that this system is important in facilitating, by charge distribution, formation of the alcoholate anion and hydride transfer to NAD+, and in the reverse reaction, neutralization of the alcoholate anion and alcohol dissociation. 

Primary alcohols dissociate to form stable alkoxides below 150 K on Rh(l 11) (212224). The range of possible subsequent bond scission steps is fairly limited, especially for smaller... 

I lie ease with which the RO group dissociates with the ease with which the corresponding alcohol dissociates in aqueous solution, which is expressed by... 

By exploding mixtures of ethane and oxygen in borosilicate bulbs, carbon monoxide, hydrogen, methane, acetylene, and ethylene have been obtained.10 140 As the initial pressure is decreased the amount of unsaturated hydrocarbons and water in the products showed a tendency to increase. The fact that no carbon is produced in these experiments and that water and ethylene are formed lends support to Bone s hydroxylation theory since it is probable that the alcohol formed in the initial step is dehydrated immediately to yield unsaturated hydrocarbon and water. The presence of hydrogen and aldehyde, especially at lower initial pressures, is also indicative of alcohol dissociation. The failure of any ethanol to appear in the product does not preclude its formation and immediate decomposition. It is hardly to be expected that ethanol if formed would exist long enough to pass out of the reaction zone and appear in the product since it is known that at the temperature of the oxidation process ethanol is entirely unstable. 

Like the reactions discussed above, this reaction involves an alcohol as the reactant. Probably, these reactions proceed through a common first step, namely the activation of the alcohol through chemisorption on the Lewis acid sites of alumina. This interaction takes place via one of the oxygen lone pairs of the alcohol, and is the first step of alcohol dissociation on Lewis acid-base pairs. 

Benzyl alcohol dissociatively adsorbs onto the active site of the catalyst to form the adsorbed alkoxide species (Eq. (12.1)), which subsequently undergoes fS-H elimination (Eq. (12.2)) in the rate-determining step to form benzaldehyde [88]. This mechanism for the transformation of benzyl alcohol to benzaldehyde has been proposed on the basis of many kinetic, electrochemical, and other studies [89, 90]. However, the mechanisms for other consecutive and side reactions, which lead to the formation of undesired by-products such as benzene, toluene, benzoic acid, and benzylbenzoate, have been a matter of debate for a long time [91-94]. It is crucial to understand these mechanisms to fine-tune or develop new catalytic... 

For hydrocarbon and synthesis of higher molecular weight alcohols, dissociation of CO is a necessary reaction condition. For methanol synthesis, the CO molecule remains intact. Hj has two roles in catalytic syngas synthesis reactions. In addition to being a reactant needed for hydrogenation of CO, it is commonly used to reduce the metalized synthesis catalysts and activate the metal surface. 

Why are carboxyhc acids so much more acidic than alcohols, even though both contain —OH groups An alcohol dissociates to give an alkoxide ion, in... 

The general PU decomposition mechanism is shown in Scheme 13 a. 122. In general, there are three main pathways for the initial degradation of the urethane linkage, which are dissociation to isocyanate and alcohol dissociation to primary amine, olefin and carbon dioxide as well as the formation of a secondary amine with elimination of carbon... 

---