Log in

Relevant bibliographies by topics / Bond dissociation enthalpy / Journal articles

To see the other types of publications on this topic, follow the link: Bond dissociation enthalpy.

Journal articles on the topic 'Bond dissociation enthalpy'

Author: Grafiati

Published: 4 June 2021

Last updated: 25 July 2025

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 50 journal articles for your research on the topic 'Bond dissociation enthalpy.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.

1

Mahmood, Asif, Muhammad Saqib, Muhammad Ali, Muhammad Imran Abdullah, and Bilal Khalid. "Theoretical investigation for the designing of novel antioxidants." Canadian Journal of Chemistry 91, no. 2 (2013): 126–30. http://dx.doi.org/10.1139/cjc-2012-0356.

Full text

Abstract:

In this study, the antioxidant potential of salicylic acid and its derivatives was determined. O–H bond dissociation enthalpy ionization potential and spin densities were computed, which are important characteristics of antioxidants. We have designed new antioxidants on the basis of information obtained from the results of this study and a literature review. O–H bond dissociation enthalpy, ionization potential, and spin densities of designed compounds were also calculated to analyze the effect of the size of the heterocyclic ring, the electronegativity of the heteroatom, the number of hydroxyl

APA, Harvard, Vancouver, ISO, and other styles

2

Poliak, Peter, and Adam Vagánek. "Torsional deformation effect on the N—H bond dissociation energy in diphenylamine." Acta Chimica Slovaca 6, no. 2 (2013): 182–86. http://dx.doi.org/10.2478/acs-2013-0029.

Full text

Abstract:

Abstract In this work, the influence of the inter-ring dihedral angles and their deformation on the energetics of diphenylamine molecule and its radical is investigated by the B3LYP/6-311++G** approach. Our approximated bond dissociation enthalpy of diphenylamine is 370.0 kJ mol-1 and it is in good agreement with the recently published experimental data. The potential functions of both the molecule and the radical with respect to the mutual aromatic ring orientations are presented. The potential function for the molecule is of a double-barrier type, whereas the radical possesses a single-barri

APA, Harvard, Vancouver, ISO, and other styles

3

Feliciano, Inês O., Daniela P. Silva, M. Fátima M. Piedade, Carlos E. S. Bernardes, and Manuel E. Minas da Piedade. "First and Second Dissociation Enthalpies in Bi-Component Crystals Consisting of Maleic Acid and L-Phenylalanine." Molecules 26, no. 18 (2021): 5714. http://dx.doi.org/10.3390/molecules26185714.

Full text

Abstract:

The energetics of the stepwise dissociation of a A:B2 bi-component crystal, according to A:B2(cr) → A:B(cr) + B(cr) and A:B(cr) → A(cr) + B(cr), was investigated using MA:Phe2 and MA:Phe (MA = maleic acid; Phe = L-phenylalanine) as model systems. The enthalpy changes associated with these sequential processes and with the overall dissociation reaction A:B2(cr) → A(cr) + 2B(cr) were determined by solution calorimetry. It was found that they are all positive, indicating that there is a lattice enthalpy gain when MA:Phe2 is formed, either from the individual precursors or by adding Phe to MA:Phe.

APA, Harvard, Vancouver, ISO, and other styles

4

Tamafo Fouegue, Aymard Didier, Julius Numbonui Ghogomu, Désiré Bikélé Mama, Nyiang Kennet Nkungli, and Elie Younang. "Structural and Antioxidant Properties of Compounds Obtained from Fe2+Chelation by Juglone and Two of Its Derivatives: DFT, QTAIM, and NBO Studies." Bioinorganic Chemistry and Applications 2016 (2016): 1–13. http://dx.doi.org/10.1155/2016/8636409.

Full text

Abstract:

The chelating ability of juglone and two of its derivatives towards Fe2+ion and the antioxidant activity (AOA) of the resulting chelates and complexes (in the presence of H2O and CH3OH as ligands) in gas phase is reported via bond dissociation enthalpy, ionization potential, proton dissociation enthalpy, proton affinity, and electron transfer enthalpy. The DFT/B3LYP level of theory associated with the 6-31+G(d,p) and 6-31G(d) Pople-style basis sets on the atoms of the ligands and the central Fe(II), respectively, was used. Negative chelation free energies obtained revealed that juglone derivat

APA, Harvard, Vancouver, ISO, and other styles

5

Ngo, Chinh Thi. "THERMOCHEMICAL PARAMETERS OF ERGOTHIONEINE: A DFT STUDY USING M06, WB97XD AND TPSSTPSS METHODS." Vietnam Journal of Science and Technology 54, no. 2C (2018): 299. http://dx.doi.org/10.15625/2525-2518/54/2c/11850.

Full text

Abstract:

Antioxidant properties of ergothioneine (ESH) have been investigated via hydrogen atomtransfer (HAT), single electron transfer-proton transfer (SET-PT) and sequential proton losselectron transfer (SPLET) mechanisms. Three new DFT methods including M06, WB97XD andTPSSTPSS at the 6-311++G(2df,2p) basis set were used to compute the thermochemicalparameters of ESH in the gas phase. Based on these methods, bond dissociation enthalpy (BDE),ionization energy (IE), proton dissociation enthalpy (PDE), proton affinity (PA) and electrontransfer enthalpy (ETE) were calculated. The results were also compar

APA, Harvard, Vancouver, ISO, and other styles

6

Xu, Shenying, Quan-De Wang, Mao-Mao Sun, Guoliang Yin, and Jinhu Liang. "Benchmark calculations for bond dissociation energies and enthalpy of formation of chlorinated and brominated polycyclic aromatic hydrocarbons." RSC Advances 11, no. 47 (2021): 29690–701. http://dx.doi.org/10.1039/d1ra05391d.

Full text

Abstract:

Benchmark calculations using state-of-the-art DFT functionals and composite methods for bond dissociation energy and enthalpy of formation of halogenated polycyclic aromatic hydrocarbons are performed.

APA, Harvard, Vancouver, ISO, and other styles

7

Le, Tien Dung. "COMPUTATIONAL STUDY OF MOLECULAR STRUCTURES AND ANTIOXIDANT MECHANISM OF OVOTHIOLS." Vietnam Journal of Science and Technology 54, no. 2C (2018): 328. http://dx.doi.org/10.15625/2525-2518/54/2c/11854.

Full text

Abstract:

In this paper, the molecular structure and antioxidant activity of ovothiols (OSH) have beenstudied by using four DFT functionals, namely B3LYP, B3PW91, X3LYP, M06 with the basisset of 6-311++G(2df,2p). Two major antioxidant mechanisms, namely, hydrogen atom transfer(HAT) and stepwise electron transfer-proton transfer (SET-PT) have been investigated andapplied on three optimized conformations of ovothiols. Bond dissociation enthalpy (BDE),vertical ionization energy (IE), proton dissociation enthalpy (PDE), chemical potential (μ),chemical hardness (η) and global electrophilicity (ω), have been

APA, Harvard, Vancouver, ISO, and other styles

8

Zhang, Hong-Yu. "On the O–H bond dissociation enthalpy of catechol." New Journal of Chemistry 27, no. 3 (2003): 453–54. http://dx.doi.org/10.1039/b212161c.

Full text

APA, Harvard, Vancouver, ISO, and other styles

9

NAJAFI, MEYSAM, MOHAMMAD NAJAFI, and HOUSHANG NAJAFI. "THEORETICAL STUDY OF THE SUBSTITUENT EFFECTS ON THE REACTION ENTHALPIES OF THE ANTIOXIDANT MECHANISMS OF STOBADINE DERIVATIVES IN THE GAS-PHASE AND WATER." Journal of Theoretical and Computational Chemistry 12, no. 02 (2013): 1250116. http://dx.doi.org/10.1142/s0219633612501167.

Full text

Abstract:

In this paper the reaction enthalpies of three antioxidant action mechanisms, HAT, SET–PT, and SPLET, for mono-substituted Stobadines were calculated in gas-phase and water. Results show that electron-withdrawing substituents increase the bond dissociation enthalpy (BDE), ionization potential (IP), and electron transfer enthalpy (ETE), while electron-donating ones cause a rise in the proton dissociation enthalpy (PDE) and proton affinity (PA). In comparison to gas-phase, water attenuates the substituent effect on all reaction enthalpies. Results show that IP and BDE values can be successfully

APA, Harvard, Vancouver, ISO, and other styles

10

Ogunyemi, Babatunde T. "Quantum chemical insights into the antioxidant mechanisms of luteolin and isorhamnetin: Elucidating structure-reactivity relationships, pharmacokinetics, and toxicity for therapeutic potential." Communication in Physical Sciences 12, no. 2 (2025): 1081–93. https://doi.org/10.4314/cps.v12i2.29.

Full text

Abstract:

This study presents a comprehensive computational evaluation of the antioxidant properties, physicochemical characteristics, pharmacokinetics, and toxicity profiles of two naturally occurring flavonoids—luteolin and isorhamnetin. Using quantum chemical descriptors and density functional theory (DFT) at the B3LYP/6-31G(d,p) level, we assessed the bond dissociation enthalpy (BDE), adiabatic ionization potential (AIP), proton dissociation enthalpy (PDE), proton affinity (PA), and electron transfer enthalpy (ETE) of both compounds. Isorhamnetin demonstrated superior antioxidant potential, with low

APA, Harvard, Vancouver, ISO, and other styles

11

Poła, Andrzej, Anna Palko-Łabuz, and Kamila Środa-Pomianek. "Theoretical Study of 2-(Trifluoromethyl)phenothiazine Derivatives with Two Hydroxyl Groups in the Side Chain-DFT and QTAIM Computations." Molecules 26, no. 17 (2021): 5242. http://dx.doi.org/10.3390/molecules26175242.

Full text

Abstract:

Phenothiazines are known as synthetic antipsychotic drugs that exhibit a wide range of biological effects. Their properties result from the structure and variability of substituents in the heterocyclic system. It is known that different quantum chemical properties have a significant impact on drug behavior in the biological systems. Thus, due to the diversity in the chemical structure of phenothiazines as well as other drugs containing heterocyclic systems, quantum chemical calculations provide valuable methods in predicting their activity. In our study, DFT computations were applied to show s

APA, Harvard, Vancouver, ISO, and other styles

12

Škorňa, Peter, Martin Michalík, and Erik Klein. "Gallic acid: thermodynamics of the homolytic and heterolytic phenolic O—H bonds splitting-off." Acta Chimica Slovaca 9, no. 2 (2016): 114–23. http://dx.doi.org/10.1515/acs-2016-0020.

Full text

Abstract:

Abstract The DFT study of primary antioxidant action of gallic acid and its carboxylic anion is presented in the gas-phase, benzene and water. Corresponding reaction enthalpies for three possible mechanisms was calculated using B3LYP/6-311++G** method. Bond dissociation enthalpy (BDE) and proton dissociation enthalpy (PDE) of 4-OH group was found to be the lowest in gas-phase as well as in both solvents approximated by IEF-PCM model. Ionization potentials (IPs) were higher than BDEs in all cases. Deprotonation of carboxylic group result in increased antioxidant potency as drop in BDE, proton a

APA, Harvard, Vancouver, ISO, and other styles

13

Lucarini, Marco, Gian Franco Pedulli, and Marta Cipollone. "Bond Dissociation Enthalpy of .alpha.-Tocopherol and Other Phenolic Antioxidants." Journal of Organic Chemistry 59, no. 17 (1994): 5063–70. http://dx.doi.org/10.1021/jo00096a061.

Full text

APA, Harvard, Vancouver, ISO, and other styles

14

Shaofeng, Li, and G. Pilcher. "Enthalpy of formation of pyridine-N-oxide: the dissociation enthalpy of the (NO) bond." Journal of Chemical Thermodynamics 20, no. 4 (1988): 463–65. http://dx.doi.org/10.1016/0021-9614(88)90184-x.

Full text

APA, Harvard, Vancouver, ISO, and other styles

15

Azuxetullatif, Azuxetullatif. "Penentuan Aktivitas Antioksidan Mirisetin, Quersetin Dan Kaempferol Berdasarkan Metode Semiempiris Austin Model (AM 1)." Jurnal Penelitian Dan Pengkajian Ilmiah Eksakta 4, no. 1 (2025): 105–9. https://doi.org/10.47233/jppie.v4i1.1977.

Full text

Abstract:

Research has been conducted on the determination of antioxidant activity using the parameters of Bond Dissociation Enthalpy (BDE), Single Electron Transfer-Proton Transfer (SET-PT), Proton Affinity (PA), and Electron Transfer Enthalpy (ETE) of myricetin, quercetin, and kaempferol compounds. Furthermore, through the geometric stages using the AM1 semi-empirical method. The results obtained showed that myricetin compounds have better antioxidant activity compared to quercetin and kaempferol compounds by considering the results of high BDE values, low SET-PT, high PA, and low ETE.

APA, Harvard, Vancouver, ISO, and other styles

16

SADASIVAM, K., R. JAYAPRAKASAM, and R. KUMARESAN. "A DFT STUDY ON THE ROLE OF DIFFERENT OH GROUPS IN THE RADICAL SCAVENGING PROCESS." Journal of Theoretical and Computational Chemistry 11, no. 04 (2012): 871–93. http://dx.doi.org/10.1142/s0219633612500599.

Full text

Abstract:

The molecular properties of robinetin and melanoxetin which are the two naturally occurring flavonoid compounds have been studied theoretically by means of density functional theory approach (DFT) at the level of B3LYP/6-311G(d,p). The analysis of computed bond dissociation enthalpy (BDE), proton dissociation enthalpy (PDE), proton affinity (PA), electron transfer enthalpy (ETE) values for both the flavonoid compounds indicate the role of B-ring for the significant antioxidant characteristics and the instability of the A-ring. It also concerns the dominant role of BDE mechanism for antioxidant

APA, Harvard, Vancouver, ISO, and other styles

17

Li, Rui, Tianshu Du, Jingxing Liu, Adelia J. A. Aquino, and Jianyu Zhang. "Theoretical Study of O-CH3 Bond Dissociation Enthalpy in Anisole Systems." ACS Omega 6, no. 34 (2021): 21952–59. http://dx.doi.org/10.1021/acsomega.1c02310.

Full text

APA, Harvard, Vancouver, ISO, and other styles

18

O'Hare, P. A. G., S. Susman, and K. J. Volin. "Thermochemistry of germanium monoselenide, and the GeSe bond dissociation enthalpy." Journal of Chemical Thermodynamics 21, no. 8 (1989): 827–36. http://dx.doi.org/10.1016/0021-9614(89)90030-x.

Full text

APA, Harvard, Vancouver, ISO, and other styles

19

Thbayh, Dalal K., Edina Reizer, Mousumi U. Kahaly, Béla Viskolcz, and Béla Fiser. "Antioxidant Potential of Santowhite as Synthetic and Ascorbic Acid as Natural Polymer Additives." Polymers 14, no. 17 (2022): 3518. http://dx.doi.org/10.3390/polym14173518.

Full text

Abstract:

A wide variety of additives are used to improve specific characteristics of the final polymeric product. Antioxidant additives (AAs) can prevent oxidative stress and thus the damage of polymeric materials. In this work, the antioxidant potential and thus the applicability of Santowhite (SW) as synthetic and ascorbic acid (Asc) as natural AAs were explored by using computational tools. Two density functional theory (DFT) methods, M05-2X and M06-2X, have been applied in combination with the 6-311++G(2d,2p) basis set in gas phase. Three antioxidant mechanisms have been considered: hydrogen atom t

APA, Harvard, Vancouver, ISO, and other styles

20

Najafi, Mohammad, Meysam Najafi, and Malihe Najafi. "Predicting the substituent and solvent effects on the radical scavenger activity of ethoxyquin derivatives: a DFT/B3LYP study." Canadian Journal of Chemistry 91, no. 6 (2013): 457–64. http://dx.doi.org/10.1139/cjc-2013-0049.

Full text

Abstract:

The radical scavenger activity of X1- and X2-substituted ethoxyquin derivatives has been investigated in the gas phase and water. The reaction enthalpies of radical scavenger activity of the studied derivatives have been calculated and compared with corresponding values of ethoxyquin. Results show that electron-withdrawing group substituents increase the bond dissociation enthalpy and ionization potential, while electron-donating group substituents cause a rise in the proton affinity. The ethoxyquin derivatives with the lowest bond dissociation enthalpy, ionization potential, and proton affini

APA, Harvard, Vancouver, ISO, and other styles

21

Dorofeeva, Olga V., and Oxana N. Ryzhova. "Enthalpy of Formation and O–H Bond Dissociation Enthalpy of Phenol: Inconsistency between Theory and Experiment." Journal of Physical Chemistry A 120, no. 15 (2016): 2471–79. http://dx.doi.org/10.1021/acs.jpca.6b02233.

Full text

APA, Harvard, Vancouver, ISO, and other styles

22

Pop, Raluca, Mariana Ştefănut, Adina Căta, Cristian Tănasie, and Mihai Medeleanu. "Ab initio study regarding the evaluation of the antioxidant character of cyanidin, delphinidin and malvidin." Open Chemistry 10, no. 1 (2012): 180–86. http://dx.doi.org/10.2478/s11532-011-0128-1.

Full text

Abstract:

AbstractA theoretical study regarding the evaluation of the antioxidant character of three of the most wide-spread anthocyanidins (cyanidin, delphinidin and malvidin) was carried out at ab initio level. Different parameters (bond dissociation enthalpy, ionization potential, proton affinity, and electron transfer enthalpy) were computed for each OH group of the compounds in order to predict their antioxidant capacity. Several molecular descriptors based on frontier molecular orbital theory (hardness, electrophilicity, frontier charge density) were also calculated, as well as the atomic charges

APA, Harvard, Vancouver, ISO, and other styles

23

Bohn, Manfred A., and Thomas M. Klapötke. "DFT and G2MP2 Calculations of the N-N Bond Dissociation Enthalpies and Enthalpies of Formation of Hydrazine, Monomethylhydrazine and Symmetrical and Unsymmetrical Dimethylhydrazine." Zeitschrift für Naturforschung B 59, no. 2 (2004): 148–52. http://dx.doi.org/10.1515/znb-2004-0205.

Full text

Abstract:

In a combined DFT (B3LYP) and G2MP2 theoretical study the following enthalpies of formation (ΔH°f) and bond dissociation enthalpies (BDE) for hydrazine, methylhydrazine (MMH), 1,1- dimethylhydrazine (UDMH) and 1,2-dimethylhydrazine (SDMH) were determined: BDE/kJ mol−1: N2H4, 278±4; MMH, 272±4; UDMH, 259±12; SDMH, 272±12. ΔH°f/kJ mol−1: N2H4, 95±6; MMH, 94±4; UDMH, 80±4; SDMH, 91±4. The bond enthalpy for the N-N bond in hydrazine amounts to BE (N-N, H2N−NH2) = 159±4 kJ mol−1.

APA, Harvard, Vancouver, ISO, and other styles

24

Zhou, Huakang, Xiangzhou Li, Yaxuan Shang, and Kai Chen. "Radical Scavenging Activity of Puerarin: A Theoretical Study." Antioxidants 8, no. 12 (2019): 590. http://dx.doi.org/10.3390/antiox8120590.

Full text

Abstract:

Puerarin is a C-glycoside of daidzein, one of the major bioactive ingredients isolated from the root of Pueraria lobata, which has a wide spectrum of pharmacological effects. Although puerarin is well-known for its effective antioxidant activity, there is seldom a systematic theoretical study on its radical scavenging activity. Herein, the free radical scavenging ability of puerarin was investigated systematically by density functional theory (DFT) calculations. The reaction activity was compared with daidzein as well. Three reaction pathways: hydrogen atom transfer (HAT), single electron tran

APA, Harvard, Vancouver, ISO, and other styles

25

Angel, Laurence A., and Kent M. Ervin. "Competitive Threshold Collision-Induced Dissociation: Gas-Phase Acidity and O−H Bond Dissociation Enthalpy of Phenol." Journal of Physical Chemistry A 108, no. 40 (2004): 8346–52. http://dx.doi.org/10.1021/jp0474529.

Full text

APA, Harvard, Vancouver, ISO, and other styles

26

ZHOU, WEIDONG, RAY Y. L. CHIM, D. J. COLLINS, and RICHARD P. TUCKETT. "PHOTOELECTRON PHOTOION COINCIDENCE STUDY OF THE FRAGMENTATION OF VALENCE STATES OF CHF2–CH3+ IN THE RANGE 12–25 eV." International Journal of Modern Physics B 23, no. 14 (2009): 3073–87. http://dx.doi.org/10.1142/s0217979209052868.

Full text

Abstract:

Using vacuum ultraviolet radiation from a synchrotron source, threshold photoelectron photoion coincidence (TPEPICO) spectroscopy has been used to study the dissociative photoionisation of CHF 2– CH 3 in the photon energy from 11.8 eV to 24.8 eV. Combining with ab initio molecular orbital calculation, fragmentation process and fragmental mechanism of the valence states of parent ion are discussed. For single bond cleavage process, a statistical mechanism might govern the C – C bond cleavage, while the kinetic energy release derived from channel CHF 2– CH 3+ → CH 3– CHF ++ F + e- shows evidence

APA, Harvard, Vancouver, ISO, and other styles

27

Da Silva, Manuel A. V. Ribeiro, M. Luisa C. C. H. Ferrão, and Arminda M. L. Magalhães. "Standard enthalpy of formation of tris(2,4-pentanedionato)cobalt(III): The mean (Co-O) bond-dissociation enthalpy." Thermochimica Acta 129, no. 2 (1988): 229–35. http://dx.doi.org/10.1016/0040-6031(88)87338-6.

Full text

APA, Harvard, Vancouver, ISO, and other styles

28

Gomes, José R. B., Maria D. M. C. Ribeiro da Silva, and Manuel A. V. Ribeiro da Silva. "Quinoxaline-1,4-dioxide: Substituent effects on the N–O bond dissociation enthalpy." Chemical Physics Letters 429, no. 1-3 (2006): 18–22. http://dx.doi.org/10.1016/j.cplett.2006.07.087.

Full text

APA, Harvard, Vancouver, ISO, and other styles

29

Nantasenamat, Chanin, Chartchalerm Isarankura-Na-Ayudhya, Thanakorn Naenna, and Virapong Prachayasittikul. "Prediction of bond dissociation enthalpy of antioxidant phenols by support vector machine." Journal of Molecular Graphics and Modelling 27, no. 2 (2008): 188–96. http://dx.doi.org/10.1016/j.jmgm.2008.04.005.

Full text

APA, Harvard, Vancouver, ISO, and other styles

30

Boli, Lusia Silfia Pulo, Nufida Dwi Aisyah, Vera Khoirunisa, Heni Rachmawati, Hermawan Kresno Dipojono, and Febdian Rusydi. "Solvent Effect on Bond Dissociation Enthalpy (BDE) of Tetrahydrocurcumin: A Theoretical Study." Materials Science Forum 966 (August 2019): 215–21. http://dx.doi.org/10.4028/www.scientific.net/msf.966.215.

Full text

Abstract:

Solvent effect on bond dissociation enthalpy (BDE) of different functional groups of tetrahydrocurcumin is investigated. This is to evaluate how the polarity of a medium affect BDE and to clarify which functional groups hold the key role in its antioxidant activity through hydrogen transfer. We occupy density functional theory to calculate BDE through geometrical optimization and frequency calculation at six sites of tetrahydrocurcumin in water, methanol and chloroform solvents. The solvents represent polar and non-polar medium. Our result shows that BDE is lower in non-polar medium and hydrog

APA, Harvard, Vancouver, ISO, and other styles

31

Mulder, Peter, Hans-Gert Korth, Derek A. Pratt, et al. "Critical Re-evaluation of the O−H Bond Dissociation Enthalpy in Phenol." Journal of Physical Chemistry A 109, no. 11 (2005): 2647–55. http://dx.doi.org/10.1021/jp047148f.

Full text

APA, Harvard, Vancouver, ISO, and other styles

32

Najafi, Meysam, and Syed Ali Raza Naqvi. "Theoretical study of the substituent effect on the hydrogen atom transfer mechanism of the irigenin derivatives antioxidant action." Journal of Theoretical and Computational Chemistry 13, no. 02 (2014): 1450010. http://dx.doi.org/10.1142/s0219633614500102.

Full text

Abstract:

In this paper, 21 substituents with various electron donating and electron withdrawing characters were placed in available positions of irigenin in order to study their effect on the O – H bond dissociation enthalpy (BDE) via DFT/B3LYP method. Results indicated the substituents in X3 and X4 positions have exerted stronger influence upon BDE values of irigenin derivatives when compared with same substituents in X1 and X2 positions. The results show that intramolecular hydrogen bond effects are able to considerably stabilize the parents and radicals. The natural bond orbital (NBO) analysis resul

APA, Harvard, Vancouver, ISO, and other styles

33

Najafi, Meysam, Mohammad Najafi, and Houshang Najafi. "DFT/B3LYP Study of the Substituent Effects on the Reaction Enthalpies of the Antioxidant Mechanisms of Sesamol Derivatives in the Gas phase and water." Canadian Journal of Chemistry 90, no. 10 (2012): 915–26. http://dx.doi.org/10.1139/v2012-087.

Full text

Abstract:

In this paper, the study of various ortho and meta–substituted Sesamol derivatives is presented. The reaction enthalpies related to three antioxidant action mechanisms HAT, SET–PT, and SPLET for substituted Sesamols, have been calculated using the DFT/B3LYP method in gas phase and water. Calculated results show that electron-withdrawing substituents increase the bond dissociation enthalpy (BDE), ionization potential (IP), and electron transfer enthalpy (ETE), while electron-donating ones cause a rise in the proton dissociation enthalpy (PDE) and proton affinity (PA). In the ortho position, sub

APA, Harvard, Vancouver, ISO, and other styles

34

Simões, Ricardo G., Filipe Agapito, Hermínio P. Diogo, and Manuel E. Minas da Piedade. "Enthalpy of Formation of Anisole: Implications for the Controversy on the O–H Bond Dissociation Enthalpy in Phenol." Journal of Physical Chemistry A 118, no. 46 (2014): 11026–32. http://dx.doi.org/10.1021/jp507267f.

Full text

APA, Harvard, Vancouver, ISO, and other styles

35

Biela, Monika, Andrea Kleinová, and Erik Klein. "Thermochemistry of antioxidant action of isoflavones and their deprotonated forms in aqueous solution: hydrogen or electron transfer?" Acta Chimica Slovaca 15, no. 1 (2022): 29–35. http://dx.doi.org/10.2478/acs-2022-0004.

Full text

Abstract:

Abstract Isoflavones possessing several weak acidic hydroxyl groups can undergo successive deprotonations in aqueous solutions. Therefore, their antioxidant properties cannot be ascribed only to the neutral forms but also to corresponding phenoxide anions. It was already confirmed that isoflavones prefer the formation of dianions in aqueous solution. For eight isoflavones and their preferred (poly)deprotonated forms, thermochemistry of hydrogen atom transfer and electron abstraction was studied in terms of corresponding reaction enthalpies, i.e., O—H bond dissociation enthalpies and ionization

APA, Harvard, Vancouver, ISO, and other styles

36

Kupaeva, N. V., and E. A. Kotenkova. "Current view on the assessment of antioxidant and antiradical activities: A mini review." IOP Conference Series: Earth and Environmental Science 854, no. 1 (2021): 012048. http://dx.doi.org/10.1088/1755-1315/854/1/012048.

Full text

Abstract:

Abstract The main problems in assessing the antioxidant properties of plant biologically active compounds are discussed in this review. Antioxidant potential should be considered as a combination of antioxidant and antiradical activities, since antiradical activity is part of the antioxidant activity and does not always coincide with antioxidant activity. The mechanisms of action and the existing experimental and computational methods for their evaluation were reviewed. Methods like FRAP, CUPRAC etc. could be used for assessment of antioxidant activity of plant compounds, but it is necessary t

APA, Harvard, Vancouver, ISO, and other styles

37

Khoirunisa, Vera, Lusia Silfia Pulo Boli, Rizka Nur Fadilla, et al. "Predicting Notable Radical Scavenging Sites of Gnetin C Using Density Functional Theory." Materials Science Forum 966 (August 2019): 229–33. http://dx.doi.org/10.4028/www.scientific.net/msf.966.229.

Full text

Abstract:

We have been investigating the scavenging activity of gnetin C theoretically in the molecular level. In this work, we perform density functional based calculations to predict the possible site of gnetin C for free radical scavenging activity. The water solvent effect is considered as polarizable continuum model. All possible scavenging sites have been evaluated by obtaining the bond dissociation enthalpy (BDE) for one hydrogen atom abstraction. The results demonstrate that O-H bonds generally have lower BDE relative to C-H bonds of gnetin C. We also find that C-H bonds in 5-membered heterocycl

APA, Harvard, Vancouver, ISO, and other styles

38

Ribeiro da Silva, Manuel A. V., Maria Luísa C. C. H. Ferrão, and Rosa M. G. Esteves da Silva. "Standard molar enthalpy of formation of tris(3-methylpentane-2,4-dionato)iron(III): the mean (FeO) bond-dissociation enthalpy." Journal of Chemical Thermodynamics 24, no. 12 (1992): 1293–98. http://dx.doi.org/10.1016/s0021-9614(05)80269-1.

Full text

APA, Harvard, Vancouver, ISO, and other styles

39

Mic, Mihaela, Adrian Pîrnău, Călin G. Floare, et al. "Antioxidant Activity Evaluation and Assessment of the Binding Affinity to HSA of a New Catechol Hydrazinyl-Thiazole Derivative." Antioxidants 11, no. 7 (2022): 1245. http://dx.doi.org/10.3390/antiox11071245.

Full text

Abstract:

Polyphenols have attained pronounced attention due to their ability to provide numerous health benefits and prevent several chronic diseases. In this study, we designed, synthesized and analyzed a water-soluble molecule presenting a good antioxidant activity, namely catechol hydrazinyl-thiazole (CHT). This molecule contains 3′,4′-dihydroxyphenyl and 2-hydrazinyl-4-methyl-thiazole moieties linked through a hydrazone group with very good antioxidant activity in the in vitro evaluations performed. A preliminary validation of the CHT developing hypothesis was performed evaluating in silico the bon

APA, Harvard, Vancouver, ISO, and other styles

40

de Aguiar, Antônio Sérgio Nakao, Lucas Barbosa Ribeiro de Carvalho, Clayson Moura Gomes, Murillo Moraes Castro, Frederico Severino Martins, and Leonardo Luiz Borges. "Computational Insights into the Antioxidant Activity of Luteolin: Density Functional Theory Analysis and Docking in Cytochrome P450 17A1." Pharmaceuticals 18, no. 3 (2025): 410. https://doi.org/10.3390/ph18030410.

Full text

Abstract:

Background: Luteolin, a flavonoid with well-documented antioxidant properties, has garnered significant attention for its potential therapeutic effects. Objectives: This study aims to investigate the antioxidant properties of luteolin under the influence of solvents, utilizing computational techniques to elucidate its interactions and its potential role as a modulator of enzymatic activities, particularly with Cytochrome 17A1. Methods: Density Functional Theory (DFT) calculations were employed to determine luteolin’s electronic and structural characteristics. Key aspects analyzed included elec

APA, Harvard, Vancouver, ISO, and other styles

41

Martínez-Cifuentes, Maximiliano, Boris Weiss-López, and Ramiro Araya-Maturana. "Theoretical Study about the Effect of Halogen Substitution on the Reactivity of Antitumor 3-Formylchromones and Their Free Radicals." Journal of Chemistry 2017 (2017): 1–5. http://dx.doi.org/10.1155/2017/9254831.

Full text

Abstract:

The mandatory presence of a chlorine atom on the aromatic ring of 6-hydroxy-3-formyl angular chromones, on the respiration inhibition of mammary carcinoma mouse, is explained through a computational study of these compounds. This study analyzes the reactivity of the neutral molecules and their free radicals, in gas phase and with water solvation, incorporated by the polarizable continuum medium (PCM) approach. Electrophilic reactivities were evaluated using Fukui (f+) and Parr (P+) functions. The stabilities of radical species formed by the abstraction of a hydrogen atom from the O-H bond were

APA, Harvard, Vancouver, ISO, and other styles

42

Ati, Fella, Soraya Abtouche, Boubekeur Maouche, and Meziane Brahimi. "Radical Scavenging Activity: DFT and Multilinear Regression Studies of Benzofuran-1,3-thiazolidin-4-one Derivatives." Acta Chimica Slovenica 72, no. 2 (2025): 359–70. https://doi.org/10.17344/acsi.2024.8963.

Full text

Abstract:

The free radical scavenging activity of benzofuran Schiff base and thiazolidinone derivatives has been investigated using the density functional theory (DFT) calculations. Three primary mechanisms were developed: sequential proton loss electron transfer (SPLET), single electron transfer followed by proton transfer (SET-PT), and hydrogen atom transfer (HAT). Several thermodynamic descriptors were computed in both gas and solvent phases at the B3LYP/6-311G and 6-311G (d, p) level of theory. Our findings suggest that compounds 3a, 3c, 3f, 4d, and 4e may scavenge free radicals through one of these

APA, Harvard, Vancouver, ISO, and other styles

43

Nam, Pham Cam, and Minh Tho Nguyen. "The Se–H bond of benzeneselenols (ArSe-H): Relationship between bond dissociation enthalpy and spin density of radicals." Chemical Physics 415 (March 2013): 18–25. http://dx.doi.org/10.1016/j.chemphys.2013.02.008.

Full text

APA, Harvard, Vancouver, ISO, and other styles

44

KALITA, DIPIKA, RAHUL KAR, and JYOTIREKHA G. HANDIQUE. "A THEORETICAL STUDY ON THE ANTIOXIDANT PROPERTY OF GALLIC ACID AND ITS DERIVATIVES." Journal of Theoretical and Computational Chemistry 11, no. 02 (2012): 391–402. http://dx.doi.org/10.1142/s0219633612500277.

Full text

Abstract:

We analyze the antioxidant property of four phenolic compounds i.e., gallic acid, methyl gallate, ethyl gallate, and 4, 5-dihydroxy 3-methoxy benzoic acid through the determination of bond dissociation enthalpy (BDE), vertical ionization potential ( IP v) in gas phase as well as in six different solvent medium. The theoretical trends of these phenolic compounds, based on BDE and IP, is compared with the scavenging activity towards HOCl . In addition, we compute and analyze the values of the density-based reactivity descriptors such as chemical potential, hardness, electrophilicity, and local s

APA, Harvard, Vancouver, ISO, and other styles

45

Jiang, Yuqin, Huaqiang Zhanga, Xiangjian Wan, et al. "2,5,8-Tri-tert-butyl-1,3,4,6,7,9-hexaazaphenalene: Synthesis, Crystal Structure and Calculation of Homolytic N–H Bond Dissociation Enthalpies." Zeitschrift für Naturforschung B 63, no. 12 (2008): 1425–30. http://dx.doi.org/10.1515/znb-2008-1214.

Full text

Abstract:

2,5,8-Tri-tert-butyl-1,3,4,6,7,9-hexaazaphenalene (6) was prepared from diethyl 2-[bis(methylsulfanyl) methylene]malonate (1) in four steps. The structure of compound 6 was confirmed by single crystal X-ray diffraction. The phenalene skeleton is nearly planar, and there is no π-π overlap between the hexaazaphenalene rings. A calculation of the homolytic bond dissociation enthalpy (BDE) was performed for compound 6 and its analogs 7 and 8, and the results were used to explain the different reactivity for these three compounds to form the corresponding radicals.

APA, Harvard, Vancouver, ISO, and other styles

46

Wei, Jing, Qian Liang, Yuxin Guo, Weimin Zhang, and Long Wu. "A Deep Insight in the Antioxidant Property of Carnosic Acid: From Computational Study to Experimental Analysis." Foods 10, no. 10 (2021): 2279. http://dx.doi.org/10.3390/foods10102279.

Full text

Abstract:

Since the deep cause for the anti-oxidation of carnosic acid (CA) against oleic acid (OA) remains unclear, we focused on exploring the CA inhibition mechanism via a combined experimental and computational study. Atomic charge, total molecular energy, phenolic hydroxyl bond dissociation enthalpy (BDE), the highest occupied molecular orbital (HOMO), and the lowest unoccupied orbital (LUMO) energy were first discussed by the B3LYP/6-31G (d,p) level, a density functional method. A one-step hydrogen atom transfer (HAT) was proposed for the anti-oxidation of CA towards OA, and the Rancimat method wa

APA, Harvard, Vancouver, ISO, and other styles

47

Cotes, Sandra, José Cotuá, and Amner Muñoz. "Calculated antioxidant activity of selected phenolic compounds." Canadian Journal of Chemistry 96, no. 3 (2018): 345–50. http://dx.doi.org/10.1139/cjc-2017-0496.

Full text

Abstract:

Determination of the corresponding bond dissociation enthalpy, ionization potential and proton affinity, dipole moment values, highest occupied molecular orbital eigenvalues, and spin density along with the bioactivity score is central to the antioxidant activity evaluation in this paper. Molecular geometries were optimized with DFT using B3LYP and UB3LYP for parent, ionic, and radical species and 6-311+G(d,p) basis set. Bioactivity, drug likeness, and drug scores were calculated using freely available cheminformatics programs for data visualization and analysis. Overall, the values revealed t

APA, Harvard, Vancouver, ISO, and other styles

48

Cobos, Carlos J., and Adela E. Croce. "Theoretical Study of the Absorption Spectrum and the Thermochemistry of the CF3OSO3 Radical." Zeitschrift für Naturforschung A 65, no. 8-9 (2010): 720–24. http://dx.doi.org/10.1515/zna-2010-8-914.

Full text

Abstract:

The UV-visible absorption spectrum of the recently reported CF3OSO3 radical has been studied by using the time-dependent generalization of the density functional theory (TDDFT). For this a set of eleven hybrid functionals combined with the 6-311+G(3df) basis set were employed. The main features of the three experimental absorption bands of CF3OSO3 recorded over the 220 - 530 nm range are well reproduced by the calculations. A dissociation enthalpy for the CF3O-SO3 bond of 19.1 kcal mol−1 is predicted at the BAC-G3MP2//B3LYP/6-311+G(3df) level of theory

APA, Harvard, Vancouver, ISO, and other styles

49

Greenberg, Arthur, Alexa R. Green, and Joel F. Liebman. "Computational Study of Selected Amine and Lactam N-Oxides Including Comparisons of N-O Bond Dissociation Enthalpies with Those of Pyridine N-Oxides." Molecules 25, no. 16 (2020): 3703. http://dx.doi.org/10.3390/molecules25163703.

Full text

Abstract:

A computational study of the structures and energetics of amine N-oxides, including pyridine N-oxides, trimethylamine N-oxide, bridgehead bicyclic amine N-oxides, and lactam N-oxides, allowed comparisons with published experimental data. Most of the computations employed the B3LYP/6-31G* and M06/6-311G+(d,p) models and comparisons were also made between the results of the HF 6-31G*, B3LYP/6-31G**, B3PW91/6-31G*, B3PW91/6-31G**, and the B3PW91/6-311G+(d,p) models. The range of calculated N-O bond dissociation energies (BDE) (actually enthalpies) was about 40 kcal/mol. Of particular interest was

APA, Harvard, Vancouver, ISO, and other styles

50

Zhang, Rui-zhou, Xiao-hong Li, and Xian-zhou Zhang. "Theoretical Study of the CCl Bond Dissociation Enthalpy and Electronic Structure of Substituted Chlorobenzene Compounds." Chinese Journal of Chemical Physics 22, no. 3 (2009): 235–40. http://dx.doi.org/10.1088/1674-0068/22/03/235-240.

Full text

APA, Harvard, Vancouver, ISO, and other styles

We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!