Tag: 100-200

Verbeek, J.; Berends, W.; Van Beek, H. C. A. published an article in 1976, the title of the article was Photochemical hydroxylation of quinoxalines.Category: quinoxaline And the article contains the following content:

Irradiation of quinoxaline (I) in acidic aqueous solution under anaerobic conditions gave 5-hydroxyquinoxaline (II) and the 1,4-dihydroquinoxaline radical cation (III). III was characterized by ESR spectroscopy. Under aerobic conditions II is the only irradiation product formed. The effect of substituents attached to the benzene nucleus of I is analyzed. The experimental process involved the reaction of 5-Chloroquinoxaline(cas: 62163-09-1).Category: quinoxaline

The Article related to photochem hydroxylation quinoxaline, esr dihydroquinoxaline radial cation, Physical Organic Chemistry: Photo- and Irradiation-Induced Reactions, Free Radical-Induced Reactions, Free Radical Reactions and other aspects.Category: quinoxaline

Referemce:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider

On May 31, 2010, Mohajeri, Afshan; Shahamirian, Mozhgan published an article.Name: 5-Chloroquinoxaline The title of the article was Substituent effect on local aromaticity in mono and di-substituted heterocyclic analogs of naphthalene. And the article contained the following:

A quant. study on local aromaticity has been performed on a series of mono- and di-substituted biheterocycles (quinoline, isoquinoline, quinoxaline, quinazoline). Three electronically based indexes (PDI, ATI, and FLU) have been employed to investigate the substituent effect on the π-electron delocalization in both heterocycle and benzenoid rings. Three typical substituents (Cl, OCH3, and CN) with different inductive and resonance power have been selected. Generally, substituent causes a reduction in aromaticity irresp. of whether it is electron attracting or electron donating. It is shown that the maximum aromaticity exhibits a similar trend of Cl > CN > OCH3 for all the studied rings. Moreover, it is found that the substituent situation with respect to the heteroatom has a significant influence on the aromaticity. It results from our study that in di-substituted derivatives, irresp. of whether the two substituents form a meta or para isomer, they preferably choose the position which leads to the maximum aromaticity character. Copyright © 2009 John Wiley & Sons, Ltd. The experimental process involved the reaction of 5-Chloroquinoxaline(cas: 62163-09-1).Name: 5-Chloroquinoxaline

The Article related to substituent effect local aromaticity substituted heterocyclic naphthalene analog, Physical Organic Chemistry: Theoretical Organic Chemical Concepts, Including Quantum and Molecular Mechanical Studies and other aspects.Name: 5-Chloroquinoxaline

Referemce:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider

On November 17, 2000, Manoharan, Mariappan; De Proft, Frank; Geerlings, Paul published an article.Electric Literature of 34413-35-9 The title of the article was Enhanced Aromaticity of the Transition Structures for the Diels-Alder Reactions of Quinodimethanes: Evidence from ab Initio and DFT Computations. And the article contained the following:

The Diels-Alder reactions of various quinodimethanes with ethylene are studied by means of ab initio MO and d. functional theory (DFT) to show the effect of aromaticity on the reaction path. The calculations reveal that these reactions are both kinetically and thermodynamically much more favored than the prototype butadiene-ethylene Diels-Alder reaction due to the aromatization process in the transition state (TS) and product. A progressive aromaticity gain is noticed during the reaction, and hence the partial π-delocalized peripheral diene ring function is coupled with the six-electron σ,π-delocalized cyclic unit resulting in an enhanced aromaticity of the TS. The magnetic criteria such as magnetic susceptibility exaltation and nucleus independent chem. shift provide definitive evidence for and fully support the aromatization process and the aromaticity of the TS. The extent of σ-π delocalization and the bond make-break at the TS are consistent with each other, and this is strongly influenced by the adjacent π-aromatization process. Moreover, the aromaticity trends in the resulting TSs and products parallel the activation and reaction energies; the extent of aromatization increases with increasing reaction rate and exothermicity. This confirms that aromaticity is the driving factor governing cycloadditions involving quinodimethanes. The experimental process involved the reaction of 5,6,7,8-Tetrahydroquinoxaline(cas: 34413-35-9).Electric Literature of 34413-35-9

The Article related to aromaticity transition state diels alder quinodimethane ab initio dft, Physical Organic Chemistry: Theoretical Organic Chemical Concepts, Including Quantum and Molecular Mechanical Studies and other aspects.Electric Literature of 34413-35-9

Referemce:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider