Sterically hindered aromatic compounds. XI. Spectral and product studies of the decomposition of N-nitrosoacetanilides

1982 ◽  
Vol 60 (5) ◽  
pp. 607-615 ◽  
Author(s):  
L. Ross C. Barclay ◽  
Julian M. Dust
Keyword(s):  
Electron Transfer ◽  
Aromatic Compounds ◽  
Diazonium Salts ◽  
Tertiary Amines ◽  
Nitroso Group ◽  
Electron Transfer Mechanism ◽  
Hydride Shift ◽  
Butyl Group ◽  
Spin Resonance

Decomposition of N-nitroso-2,4,6-tri-tert-butylacetanilide (1) in benzene forms products 2,4,6-tri-tert-butylphenyl acetate (3), 3-(3,5-di-tert-butylphenyl)-2-acetoxy-2-methylpropane (4), and hydrocarbons 3-(3,5-di-tert-butylphenyl)- and 1-(3,5-di-tert-butylphenyl)-2-methylpropene (5 and 6) explained by a reactive aryl cation (2), the rearranged products (4, 5, 6) originating from a 1,5-hydride shift from an orthotert-butyl group in 2. In contrast, decomposition of 1 in triethylamine forms products 1,3,5-tri-tert-butylbenzene (10), 2,4,6-tri-tert-butylacetanilide (15), and 2-(3,5-di-tert-butylphenyl)-2-methylpropanal oxime (13), expected of a free radical pathway. Electron spin resonance evidence is given for intermediates formed by rearrangement of the 2,4,6-tri-tert-butylphenyl radical and spin trapped by the nitroso group of 1. CIDNP and esr studies on the dediazoniation of N-nitrosoacetanilide and aniline in the presence of tertiary amines support the proposed electron transfer mechanism. The results are briefly discussed in terms of the role of steric effects and electron transfer in the dediazoniation of nitrosoacetanilides and diazonium salts.

Improving peroxymonosulfate activation by copper ion-saturated adsorbent-based single atom catalysts for the degradation of organic contaminants: electron-transfer mechanism and the key role of Cu single atoms

2021 ◽  
Author(s):  
Jingwen Pan ◽  
Baoyu Gao ◽  
Pijun Duan ◽  
Kangying Guo ◽  
Muhammad Akram ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Organic Contaminants ◽  
High Salinity ◽  
Copper Ion ◽  
Single Atom ◽  
Electron Transfer Mechanism ◽  
Persulfate Oxidation ◽  
Single Atoms ◽  
Oxidation Technology

Nonradical pathway-based persulfate oxidation technology is considered to be a promising method for high-salinity organic wastewater treatment.

Role of tertiary amines in enhancing trihalomethane and haloacetic acid formation during chlorination of aromatic compounds and a natural organic matter extract

2018 ◽  
Vol 4 (5) ◽  
pp. 663-679 ◽  
Author(s):  
Kun Huang ◽  
Amisha D. Shah
Keyword(s):  
Organic Matter ◽  
Organic Compound ◽  
Natural Organic Matter ◽  
Aromatic Compounds ◽  
Acid Formation ◽  
Tertiary Amines ◽  
Haloacetic Acid ◽  
Anthropogenic Inputs

Tertiary amines are prevalent in waters due to anthropogenic inputs and are known to enhance organic compound degradation while increasing disinfection by-product (DBP) formation, via the strong chlorinating agent, R3N–Cl+.

Surface photochemistry: Semiconductor mediated reactions of some saturated strained hydrocarbons

1988 ◽  
Vol 66 (7) ◽  
pp. 1579-1588 ◽  
Author(s):  
N. Colin Baird ◽  
Anthony M. Draper ◽  
Paul de Mayo
Keyword(s):  
Electron Transfer ◽  
Quantum Yield ◽  
Transfer Process ◽  
Radical Cations ◽  
Thermal Reaction ◽  
Electron Transfer Process ◽  
Electron Transfer Mechanism ◽  
Valence Isomerization ◽  
Back Electron Transfer

Quadricyclane (1) and 1,8-bishoniocubane (2) have been found to undergo valence isomerization to norborndiene and tricyclo[4.2.2.02,5]deca-3,7-diene, respectively, on illuminated CdS and ZnO. An electron transfer mechanism is proposed. Quantum yield, solvent effects, the role of oxygen, and the quenching of the reaction were investigated, and were consistent with this interpretation. The thermal reaction of 1 on CdS was also suggested to be an electron transfer process involving, in this case, defects or trapped holes on the surface of the semiconductor. An examination of a series of strained hydrocarbons structurally related to 1 (tetracyclo[3.3.0.02,8.04,6]octane 3, pentacyclo[4.3.0.02,4.03.805,7]nonane 4 and pentacyclo[4.4.0.02,4.03,8.05,7]decane 5) resulted, largely, in a demonstration of the resistance of their respective radical cations to rearrangement prior to back electron transfer. Calculations by MNDO, in combination with a modified version of MM2, were used to explore the differences in the reactivity of the radical cations of 1, 3, 4, 5, and an interpretation is presented.

A nucleus-coupled electron transfer mechanism for TiO2-catalyzed water splitting

2015 ◽  
Vol 17 (26) ◽  
pp. 16779-16783 ◽  
Author(s):  
Michael Lucking ◽  
Yi-Yang Sun ◽  
Damien West ◽  
Shengbai Zhang
Keyword(s):  
Electron Transfer ◽  
Water Splitting ◽  
Oxygen Evolution ◽  
Oxygen Evolution Reaction ◽  
Transfer Mechanism ◽  
Electron Transfer Mechanism

A nucleus-coupled electron transfer mechanism with a clearly identified role of photoholes is proposed for the TiO2-catalyzed oxygen-evolution reaction.

Oxidative N-Dealkylation of Tertiary Amines with Tetraethylammonium Periodate Catalyzed by Metal Complexes

2017 ◽  
Vol 70 (3) ◽  
pp. 233 ◽  
Author(s):  
Daisy Bhat ◽  
Nidhi Sharma
Keyword(s):  
Electron Transfer ◽  
Metal Complexes ◽  
Oxygen Transfer ◽  
Hydrogen Abstraction ◽  
Product Yield ◽  
Product Formation ◽  
Transfer Mechanism ◽  
Tertiary Amines ◽  
Electron Transfer Mechanism ◽  
Oxygenated Products

The oxidative N-dealkylation of tertiary amines, N,N-dimethylaniline and N,N-diethylaniline, catalyzed by some sterically hindered FeIII complexes and tetraethylammonium periodate as oxidant gave the corresponding N-dealkylated and mono-oxygenated products in good yields. The presence of electronegative atoms on the catalyst complexes influenced the product yield. The presence of H-atom abstractor 2,6-di-tert-butyl-4-methylphenol did not influence product formation, thereby suggesting that the reaction proceeded predominantly via a one-electron transfer mechanism rather than via hydrogen abstraction. Tetraethylammonium periodate favoured oxygen transfer to the substrate.

Sterically hindered aromatic compounds. IX. Electron spin resonance and product studies of the dediazoniation reaction

1979 ◽  
Vol 57 (16) ◽  
pp. 2172-2179 ◽  
Author(s):  
L. Ross C. Barclay ◽  
Alexander G. Briggs ◽  
William E. Briggs ◽  
Julian M. Dust ◽  
Jean A. Gray
Keyword(s):  
Methylene Chloride ◽  
Pivalic Acid ◽  
Spin Trapping ◽  
Nitroso Group ◽  
Tert Butyl ◽  
Aryl Radicals ◽  
Butyl Group ◽  
Tert Butyl Group ◽  
Spin Resonance ◽  
Formed Product

An esr study of the dediazoniation of 2,4,6-tri-tert-butylaniline with butyl nitrite in methylene chloride indicated the formation of the 2,4,6-tri-tert-butylphenyl radical which was spin trapped by the butyl nitrite. The persistent 2,4,6-tri-tert-butylphenoxy radical was also formed. Product studies from reactions catalyzed by pivalic acid indicate a novel rearrangement of an ortho-tert-butyl group under dediazoniation conditions forming such products as: 3-(3,5-di-tert-butylphenyl)-2-methylpropene (4), 1-(3,5-di-tert-butylphenyl)-2-methylpropene (5), 3-(3,5-di-tert-butylphenyl)-2-methyl-2-propanol (6), 3-(3,5-di-tert-butylphenyl)-2-butoxy-2-methylpropane (7), 3-(3,5-di-tert-butylphenyl)-2-methyl-2-trimethylacetoxypropane (8), 2,4,6-tri-tert-butylphenyl trimethylacetate (9), and 2,4,6-tri-tert-butyl-1,4-quinol (10). The major products (4–7) are accounted for by a free radical pathway by rearrangement of the 2,4,6-tri-tert-butyl-phenyl radical. The minor products (esters 8 and 9) probably form by competing ionic reactions. N-Nitroso-2,4,6-tri-tert-butylacetanilide decomposes (at least in part) by a radical pathway leading to the rearranged radical (CH3)2ĊCH2—Ar which was spin trapped by the nitroso group of the substrate. Spin trapping experiments during the dediazoniation of 2,5-di-tert-butylaniline similarly gave evidence for the formation of aryl radicals.

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