Decomposition of aromatics

The Thermal Decomposition of Aromatic Ethers. According to the results of Table I, the bond scission of oxygen containing polynucleus aromatic structure of coal at liquefaction temperature of 450°C seems to occur mainly at methylene or ether structures. Therefore, it will be very important to study the... 

Phenolic compounds may enhance the rate of decomposition of aromatic ether, because the phenoxy radical may be stabilized by solvation (18) or hydrogen bonding (19) with phenolic compounds and may result in the subsequent hydrogen transfer reaction from hydrogen donating solvent or phenols (20). 

Some of the investigations carried out in the first half of the twentieth century were related to CL associated with thermal decomposition of aromatic cyclic peroxides [75, 76] and the extremely low-level ultraviolet emission produced in different reaction systems such as neutralization and redox reactions involving oxidants (permanganate, halogens, and chromic acid in combination with oxalates, glucose, or bisulfite) [77], In this period some papers appeared in which the bright luminescence emitted when alkali metals were exposed to oxygen was reported. The phenomenon was described for derivatives of zinc [78], boron [79], and sodium, potassium, and aluminum [80]. 

The decomposition of aromatic diazonium salts in neutral or alkaline solution generates radicals that attack supernatant benzene.64... 

The carbon-carbon double bond can be reduced by diimide prepared in solution in a number of ways.34 183,184 Oxidation of hydrazine with oxygen (air) or H202 in the presence of a catalytic amount of Cu(II) ion was the first method to generate and use diimide in hydrogenation.183-185 Acid-catalyzed decomposition of alkali azido-dicarboxylates,185,186 as well as thermal or base-catalyzed decomposition of aromatic sulfonyl hydrazides,183,184 are also useful methods for preparing the diimide reducing agent. 

Although pseudomonads are well known for aerobic decomposition of aromatic compounds, some strains of Pseudomonas, as well as many other bacteria, are able to degrade aromatic compounds under completely anerobic conditions.166 167 Benzoate can be converted to benzoyl-CoA and the ring can be partially reduced in two ATP- and NADH-dependent reactions (Eq. 25-9). The first of these reduction steps is unusual because ATP is apparently needed to drive the reaction.166,166a,b This is analogous to the need for ATP in nitrogen fixation (Eq. 24-6, step b). 

K. R. Jennings, Collision-induced decompositions of aromatic molecular ions, Int. J. Mass Spectrom. Ion Process., 1 (1968) 227-235. 

Decomposition of Aromatic Acyl Peroxides. The decomposition of aromatic acyl peroxides in liquid aromatic compounds is similar to the decomposition of nitrosoacetylarylamines and appears to involve the intermediate formation of free radicals. When dibenzoyl peroxide is heated in benzene, biphenyl, benzoic acid, and small amounts of phenyl benzoate, p-terphenyl, and quaterphenyl are produced. 4 That the second component enters into the reaction is shown by the formation of 4-chlorobiphenyl from the decomposition of di-p-chlorobenzoyl peroxide in benzene 84 and of dibenzoyl peroxide in-chlorobenzene 86... 

Alexander, M., Aleem, M.I.H. (1961) Effect of chemical structure on microbial decomposition of aromatic herbicides. J. Agric. Food Chem. 9, 44-47. 

The decomposition of aromatic BMIs follows another pathway involving succinimide ring cleavage followed by carbon monoxide evolution. Moreover it must be pointed out that at temperature as low as 260 °C a depolymerization process can occur probably depending on the chain mobility as was evidenced for model compounds [81]. 

Jensen HL, Gundersen K. 1955. Biological decomposition of aromatic nitro-compounds. Nature 4451 341. 

Batchwise Acid Decomposition of Aromatic Triazenes Using Hydrogen Fluoride/Pyridine... 

Fluoroaromatic Compounds by Acid Decomposition of Aromatic Triazcncs with Hydrogen Fluoride/Fyiidinc General Procedure ... 

Aqueous hydrogen fluoride can be used for the acid decomposition of aromatic triazenes. Thus, 40% aqueous hydrogen fluoride is used in the preparation of fluorotamoxifen (2), a possible estrogen-rcceptor imaging agent, from triazene... 

Fluorotamoxifen (2) Typical Procedure for the Acid Decomposition of Aromatic Triazenes with 40 %. Aqueous Hydrogen Fluoridc ... 

In the course of thermal decomposition of aromatic nitro compounds free radicals are formed. The ESR signals were detected by Janzen [202], Japanese workers [203] and Soviet workers [204], The latter authors obtained strong signals from picric acid after an induction period of 30-5 min at 190-210 C respectively. 

Vapor Phase Decomposition of Aromatic Hydrocarbons by Electric Discharge... 

Hydrogen abstraction from lipids by triplet states of benzophenone derivatives followed directly by the use of laser flash techniques allows the separation of physical quenching processes from chemical reactions of the excited state. 98 xhe production of 2 by the photochemical decomposition of aromatic endoperoxides has also been studied by ps kinetic procedures. 99 mechanistic study has also been reported on the phototransformation of 3-nitrophenol in aqueous solution. 99 There is a strong wavelength dependence of the low quantum yield for the phototransformation in this system. 

---