Theoretical models for solvated electrons

Feng, Da‐Fei; Kevan, Larry

doi:10.1021/cr60323a001

Cited by 163 publications

(107 citation statements)

References 23 publications

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“…26 The cavity model of e - aq has already been proposed in the literature. 58 The initial structure (4H 2 O-base) •- (Base = A, T, G, C or U), thus generated, was fully optimized using the B3LYP/6-31++G** method including PCM to account for the full solvation effect. The spin density plot of the fully optimized structures showed that e - aq is completely localized in the cavity enclosed by 4H 2 O.…”

Section: Resultsmentioning

confidence: 99%

Do Solvated Electrons (e_aq^–) Reduce DNA Bases? A Gaussian 4 and Density Functional Theory-Molecular Dynamics Study

et al. 2016

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The solvated electron (e-aq) is a primary intermediate after an ionization event that produces reductive DNA damage. Accurate determination of standard redox potentials (E°) of nucleobases and of e-aq determine the extent of reaction of e-aq with nucleobases. In this work, E° of e-aq and of nucleobases have been calculated employing the accurate ab initio Gaussian-4 theory including the polarizable continuum model (PCM). The Gaussian-4-calculated E° of e-aq (-2.86 V) is in excellent agreement with the experimental one (-2.87 V). The Gaussian-4-calculated E° of nucleobases in dimethylformamide (DMF) lie in the range (-2.36 V to -2.86 V); they are in reasonable agreement with the experimental E° in DMF and have a mean unsigned error (MUE) = 0.22 V. However, inclusion of specific water molecules reduces this error significantly (MUE= 0.07). Employing a model of e-aq-nucleobase complex with 6 water molecules, reaction of e-aq with the adjacent nucleobase is investigated using approximate ab initio molecular dynamics (MD) simulations including PCM. Our MD simulations show that e-aq transfers to uracil, thymine, cytosine and adenine, within 10 to 120 fs and e-aq reacts with guanine only when a water molecule forms a hydrogen bond to O6 of guanine which stabilizes the anion radical.

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Section: Resultsmentioning

confidence: 99%

Do Solvated Electrons (e_aq^–) Reduce DNA Bases? A Gaussian 4 and Density Functional Theory-Molecular Dynamics Study

et al. 2016

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“…The broad absorption spectrum of e aq − with a maximum absorbance around 720 nm was first reported using pulse radiolysis of irradiated water (Hart and Boag, 1962). Owing to its fundamental importance in biology, radiation chemistry, photochemistry and nanotechnology, knowledge about its physical and chemical properties using experiment and theory has been the locus of considerable debate (Bartels et al, 2005; Coe et al, 2008; Feng and Kevan, 1980; Kumar et al, 2015; Larsen et al, 2010; Siefermann et al, 2010; von Sonntag, 2006; Uhlig et al, 2012; Young and Neumark, 2012). …”

Section: Electron Reaction With Dnamentioning

confidence: 99%

Gamma and ion-beam irradiation of DNA: Free radical mechanisms, electron effects, and radiation chemical track structure

Sevilla

Becker

Kumar

et al. 2016

Radiation Physics and Chemistry

119

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The focus of our laboratory’s investigation is to study the direct-type DNA damage mechanisms resulting from γ-ray and ion-beam radiation-induced free radical processes in DNA which lead to molecular damage important to cellular survival. This work compares the results of low LET (γ−) and high LET (ion-beam) radiation to develop a chemical track structure model for ion-beam radiation damage to DNA. Recent studies on protonation states of cytosine cation radicals in the N1-substituted cytosine derivatives in their ground state and 5-methylcytosine cation radicals in ground as well as in excited state are described. Our results exhibit a radical signature of excitations in 5-methylcytosine cation radical. Moreover, our recent theoretical studies elucidate the role of electron-induced reactions (low energy electrons (LEE), presolvated electrons (epre−), and aqueous (or, solvated) electrons (eaq−)). Finally DFT calculations of the ionization potentials of various sugar radicals show the relative reactivity of these species.

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“…The philosophy of the one-electron approach clearly has its origins in the primitive one-electron static models of the hydrated electron. 65 The first such statistical approach with explicit quantum mechanical treatment for the hydrated electron was based on the Feynman path-integral (PI) theory 77 formulated within either molecular dynamics (PIMD) 78,79,80 or Monte Carlo (PIMC) frameworks. 81 In these path integral simulations of the hydrated electron, only the excess electron is described quantum mechanically by its probability density, and the solvent molecules behave classically.…”

Section: One-electron Statistical Finite Temperature Approaches: Adimentioning

confidence: 99%

“…65,214 The first successful attempts to simulate the absorption spectrum and suggest a detailed description of the physics underlying the optical spectrum were based on one-electron models. A pioneering simulation study came from Rossky, Friesner, and coworkers.…”

mentioning

confidence: 99%

Theoretical Studies of Spectroscopy and Dynamics of Hydrated Electrons

2012

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Theoretical models for solvated electrons

Cited by 163 publications

References 23 publications

Do Solvated Electrons (e_aq^–) Reduce DNA Bases? A Gaussian 4 and Density Functional Theory-Molecular Dynamics Study

Do Solvated Electrons (e_aq^–) Reduce DNA Bases? A Gaussian 4 and Density Functional Theory-Molecular Dynamics Study

Gamma and ion-beam irradiation of DNA: Free radical mechanisms, electron effects, and radiation chemical track structure

Theoretical Studies of Spectroscopy and Dynamics of Hydrated Electrons

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Theoretical models for solvated electrons

Cited by 163 publications

References 23 publications

Do Solvated Electrons (eaq–) Reduce DNA Bases? A Gaussian 4 and Density Functional Theory-Molecular Dynamics Study

Do Solvated Electrons (eaq–) Reduce DNA Bases? A Gaussian 4 and Density Functional Theory-Molecular Dynamics Study

Gamma and ion-beam irradiation of DNA: Free radical mechanisms, electron effects, and radiation chemical track structure

Theoretical Studies of Spectroscopy and Dynamics of Hydrated Electrons

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Do Solvated Electrons (e_aq^–) Reduce DNA Bases? A Gaussian 4 and Density Functional Theory-Molecular Dynamics Study

Do Solvated Electrons (e_aq^–) Reduce DNA Bases? A Gaussian 4 and Density Functional Theory-Molecular Dynamics Study