4 articles for “Proton transfer”

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Research ArticleOpen accessPhrase in the titleTheoretical Study of the Proton Transfer in EnaminonesRita Sabah EliasProblem statement: Hydrogen bonding has a vital rule to unrevealed the nature of many different interactions both in gas phase and condensed media thus it is one of the most important concepts in chemistry. Enaminoes with their ability to form intrahydrogen bonded cheated rings represent one of the suitable compounds to study such concept. Approach: The three possible tautomers of … …American Journal of Applied Sciences, Vol. 9, Issue 1 · 23 Nov 2011 · 7,418 accessesView PDF Cite

Research ArticleOpen accessIn the abstractThermodynamic Inference of the Antioxidant Process of Malic Acid and Its Structural AnalogsHan Wu, Wenhao Dong et al.Two structural analogs of Malic Acid (MA), 2-isopropylmalic Acid (2-IPMA), and 3-isopropylmalic Acid (3-IPMA) were recently identified and separated from wine. Although they have been shown to have antioxidant activity, the mechanism of their actions is still unclear. Antioxidant activities of 2-IPMA and MA were tested through DPPH, ABTS, and PTIO methods and the antioxidant-related thermodynamic properties were evaluated using … …American Journal of Biochemistry and Biotechnology, Vol. 20, Issue 4 · 30 Oct 2024 · 4,824 accessesView PDF Cite

Research ArticleOpen accessIn the abstractAn Initio Theoretical Study for the Electronic Spectra of β-ThioxoketonesRita S. Elias, Bahjat A. Saeed, Dhiyaa K. MuslemProblem statement: β-thioxoketones exist as equilibrium mixtures of the tautomeric enol and enethiol forms which interconvert very rapidly by intramolecular chelate proton transfer. Accordingly their electronic spectra in the u.v.-visible region exhibit absorption bands arising from transitions within the electronic systems involved in these tautomers. Approach: The structures of several β-thioxoketones were geometrically optimized using B3LYP/cc-pVTZ, B3LYP/6-311++G (2d,p), PM2/6-311++G(2d,p) and … …American Journal of Applied Sciences, Vol. 9, Issue 1 · 24 Nov 2011 · 7,854 accessesView PDF Cite

Research ArticleOpen accessIn the abstractIntrahydrogen Bonding and Transition States Between Enol and Enethiol Tautomers in β-ThioxoketonesBahjat A. Saeed, Rita S. Elias, Ebraheem Abdu MusadProblem statement: Hydrogen bonding is one of the most important concepts in chemistry because it is crucial to understand many different interactions both in gas phase and in condensed media. A particular subset is presented by the intramolecular hydrogen bonds where two ends of the same molecule interact, resulting in a ringlike structure. Approach: The study involved theoretical investigation of … …American Journal of Applied Sciences, Vol. 8, Issue 8 · 18 Jul 2011 · 7,452 accessesView PDF Cite