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Abstract
Weakly bound non-valence anions are molecular systems where the excess electron stabilizes in a very diffuse orbital whose size, shape, and binding energy (∼1-100 meV) are governed by the long-range electrostatic potential of the molecule. Its binding energy comes mainly from charge-dipole or charge-multipole interactions or dispersion forces. While highly correlated methods, like coupled cluster methods, are considered to be the state of the art for describing anionic systems, especially when the electron lies in a very diffuse orbital, we consider here the possibility to use DFT-based calculations. In such molecular anions, the outer electron experiences long-range exchange and correlation interactions. We show that DFT can describe long-range bound states provided that a correct asymptotic exchange and correlation potential is used, namely, that from a range-separated hybrid functional. This opens an alternative to the computationally demanding highly correlated method calculations. It is also suggested that the study of weakly bound anions could help in the construction of new DFT potentials to study systems where nonlocal effects are significant.
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Affiliation(s)
- Guillaume Thiam
- Université de Lyon, Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, UMR5306, F-69622 Villeurbanne, France
| | - Franck Rabilloud
- Université de Lyon, Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, UMR5306, F-69622 Villeurbanne, France
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2
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Narayanan S J J, Tripathi D, Verma P, Adhikary A, Dutta AK. Secondary Electron Attachment-Induced Radiation Damage to Genetic Materials. ACS OMEGA 2023; 8:10669-10689. [PMID: 37008102 PMCID: PMC10061531 DOI: 10.1021/acsomega.2c06776] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/23/2022] [Accepted: 02/20/2023] [Indexed: 06/19/2023]
Abstract
Reactions of radiation-produced secondary electrons (SEs) with biomacromolecules (e.g., DNA) are considered one of the primary causes of radiation-induced cell death. In this Review, we summarize the latest developments in the modeling of SE attachment-induced radiation damage. The initial attachment of electrons to genetic materials has traditionally been attributed to the temporary bound or resonance states. Recent studies have, however, indicated an alternative possibility with two steps. First, the dipole-bound states act as a doorway for electron capture. Subsequently, the electron gets transferred to the valence-bound state, in which the electron is localized on the nucleobase. The transfer from the dipole-bound to valence-bound state happens through a mixing of electronic and nuclear degrees of freedom. In the presence of aqueous media, the water-bound states act as the doorway state, which is similar to that of the presolvated electron. Electron transfer from the initial doorway state to the nucleobase-bound state in the presence of bulk aqueous media happens on an ultrafast time scale, and it can account for the decrease in DNA strand breaks in aqueous environments. Analyses of the theoretically obtained results along with experimental data have also been discussed.
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Affiliation(s)
- Jishnu Narayanan S J
- Department
of Chemistry, Indian Institute of Technology
Bombay, Powai, Mumbai 400076, India
| | - Divya Tripathi
- Department
of Chemistry, Indian Institute of Technology
Bombay, Powai, Mumbai 400076, India
| | - Pooja Verma
- Department
of Chemistry, Indian Institute of Technology
Bombay, Powai, Mumbai 400076, India
| | - Amitava Adhikary
- Department
of Chemistry, Oakland University, 146 Library Drive, Rochester, Michigan 48309, United States
| | - Achintya Kumar Dutta
- Department
of Chemistry, Indian Institute of Technology
Bombay, Powai, Mumbai 400076, India
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3
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Verma P, Narayanan S J J, Dutta AK. Electron Attachment to DNA: The Protective Role of Amino Acids. J Phys Chem A 2023; 127:2215-2227. [PMID: 36881498 DOI: 10.1021/acs.jpca.2c06624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2023]
Abstract
We have studied the effect of amino acids on the electron attachment properties of a DNA nucleobase, with cytosine as a model system. The equation of motion coupled cluster theory with an extended basis set has been used to simulate the electron-attached state of the DNA model system. Arginine, alanine, lysine, and glycine are the four amino acids considered to investigate their role in electron attachment to a DNA nucleobase. The electron attachment to cytosine in all the four cytosine-amino acid gas-phase dimer complexes follows a doorway mechanism, where the electron gets transferred from the initial dipole-bound doorway state to the final nucleobase-bound state through the mixing of electronic and nuclear degrees of freedom. When cytosine is bulk-solvated with glycine, the glycine-bound state acts as the doorway state, where the initial electron density is localized on the bulk amino acid and away from the nucleobase, thus leading to the physical shielding of the nucleobase from the incoming electron. At the same time, the presence of amino acids can increase the stability of the nucleobase-bound anionic state, which can suppress the sugar-phosphate bond rupture caused by dissociative electron attachment to DNA.
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Affiliation(s)
- Pooja Verma
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Jishnu Narayanan S J
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Achintya Kumar Dutta
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
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4
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Das S, Samanta K. Recent Advances in the Study of Negative-Ion Resonances Using Multiconfigurational Propagator and a Complex Absorbing Potential. Chemphyschem 2023; 24:e202200546. [PMID: 36223261 DOI: 10.1002/cphc.202200546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 10/12/2022] [Indexed: 02/03/2023]
Abstract
The transient resonances are a challenge to bound state quantum mechanics. These states lie in the continuum part of the spectrum of the Hamiltonian. For this, one has to treat a continuum problem due to electron-molecule scattering and the many-electron correlation problem simultaneously. Moreover, the description of a resonance requires a wavefunction that bridges the part that resembles a bound state with another that resembles a continuum state such that the continuity of the wavefunction and its first derivative with respect to the distance between the incoming projectile and the target is maintained. A review of the recent advances in the theoretical investigation of the negative-ion resonances (NIR) is presented. The NIRs are ubiquitous in nature. They result from the scattering of electrons off of an atomic or molecular target. They are important for numerous chemical processes in upper atmosphere, space and even biological systems. A contextual background of the existing theoretical methods as well as the newly-developed multiconfigurational propagator tools based on a complex absorbing potential are discussed.
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Affiliation(s)
- Subhasish Das
- School of Basic Sciences, Indian Institute of Technology Bhubaneswar, Kansapada, Argul, 752050, India
| | - Kousik Samanta
- School of Basic Sciences, Indian Institute of Technology Bhubaneswar, Kansapada, Argul, 752050, India
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5
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Narayanan S J J, Bachhar A, Tripathi D, Dutta AK. Electron Attachment to Wobble Base Pairs. J Phys Chem A 2023; 127:457-467. [PMID: 36622294 DOI: 10.1021/acs.jpca.2c07469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
We have analyzed the low-energy electron attachment to wobble base pairs using the equation of motion coupled cluster method and extended basis sets. A doorway mechanism exists for the attachment of the additional electron to the base pairs, where the initially formed dipole-bound anion captures the incoming electron. The doorway dipole-bound anionic state subsequently leads to the formation of a valence-bound state, and the transfer of extra electron occurs by mixing of electronic and nuclear degrees of freedom. The formation of the valence-bound anion is associated with proton transfer in hypoxanthine-cytosine and hypoxanthine-adenine base pairs, which happens through a concerted electron-proton transfer process. The calculated rate constant for the dipole-bound to valence-bound transition in wobble base pairs is slower than that observed in the Watson-Crick guanine-cytosine base pair.
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Affiliation(s)
- Jishnu Narayanan S J
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai400076, India
| | - Arnab Bachhar
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai400076, India
| | - Divya Tripathi
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai400076, India
| | - Achintya Kumar Dutta
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai400076, India
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6
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Kang DH, Kim J, Eun HJ, Kim SK. Experimental Observation of the Resonant Doorways to Anion Chemistry: Dynamic Role of Dipole-Bound Feshbach Resonances in Dissociative Electron Attachment. J Am Chem Soc 2022; 144:16077-16085. [PMID: 35973092 DOI: 10.1021/jacs.2c06334] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Anion chemical dynamics of autodetachment and fragmentation mediated by the dipole-bound state (DBS) have been thoroughly investigated in a state-specific way by employing the picosecond time-resolved or the nanosecond frequency-resolved spectroscopy combined with the cryogenically cooled ion trap and velocity-map imaging techniques. For the ortho-, meta-, or para-iodophenoxide anion (o-, m-, or p-IPhO-), the C-I bond rupture occurs via the nonadiabatic transition from the DBS to the nearby valence-bound states (VBS) of the anion where the vibronic coupling into the S1 (πσ*) state (repulsive along the C-I bond extension coordinate) should be largely responsible. Dynamic details are governed by the isomer-specific nature of the potential energy surfaces in the vicinity of the DBS-VBS curve crossings, as manifested in the huge different chemical reactivity of o-, m-, or p-IPhO-. It is confirmed here that the C-I bond dissociation is mediated by DBS resonances, providing the foremost evidence that the metastable DBS plays the critical role as the doorway into the anion chemistry especially of the dissociative electron attachment (DEA). The fragmentation channel is dominant when it is mediated by the DBS resonances located below the electron-affinity (EA) threshold, whereas it is kinetically adjusted by the competitive autodetachment when the DBS resonances above EA convey the electron to the valence orbitals. The product yield of the C-I bond cleavage is strongly mode-dependent as the rate of the concomitant autodetachment is much influenced by the characteristics of the individual vibrational modes, paving a new way of the reaction control of the anion chemistry.
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Affiliation(s)
- Do Hyung Kang
- Department of Chemistry, KAIST, Daejeon 34141, Republic of Korea
| | - Jinwoo Kim
- Department of Chemistry, KAIST, Daejeon 34141, Republic of Korea
| | - Han Jun Eun
- Department of Chemistry, KAIST, Daejeon 34141, Republic of Korea
| | - Sang Kyu Kim
- Department of Chemistry, KAIST, Daejeon 34141, Republic of Korea
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7
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Pant R, Ranga S, Bachhar A, Dutta AK. Pair Natural Orbital Equation-of-Motion Coupled-Cluster Method for Core Binding Energies: Theory, Implementation, and Benchmark. J Chem Theory Comput 2022; 18:4660-4673. [PMID: 35786933 DOI: 10.1021/acs.jctc.2c00165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We present the theory and implementation of a lower scaling core-valence separated equation-of-motion coupled-cluster approach based on domain-based local pair natural orbitals for core binding energies. The accuracy of the new method has been compared with that of the standard equation-of-motion coupled-cluster method and experimentally measured results. The use of pair natural orbitals significantly reduces the computation cost and can be applied to large molecules.
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Affiliation(s)
- Rakesh Pant
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Santosh Ranga
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Arnab Bachhar
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Achintya Kumar Dutta
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
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8
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Kang DH, Kim J, Kim SK. Dynamic role of the correlation effect revealed in the exceptionally slow autodetachment rates of the vibrational Feshbach resonances in the dipole-bound state. Chem Sci 2022; 13:2714-2720. [PMID: 35356673 PMCID: PMC8890126 DOI: 10.1039/d1sc05481c] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Accepted: 02/03/2022] [Indexed: 11/21/2022] Open
Abstract
Real-time autodetachment dynamics of the loosely bound excess electron from the vibrational Feshbach resonances of the dipole-bound states (DBS) of 4-bromophonoxide (4-BrPhO-) and 4-chlorophenoxide (4-ClPhO-) anions have been thoroughly investigated. The state-specific autodetachment rate measurements obtained by the picosecond time-resolved pump-probe method on the cryogenically cooled anions exhibit an exceptionally long lifetime (τ) of ∼823 ± 156 ps for the 11'1 vibrational mode of the 4-BrPhO- DBS. Strong mode-dependency in the wide dynamic range has also been found, giving τ ∼ 5.3 ps for the 10'1 mode, for instance. Though it is nontrivial to get the state-specific rates for the 4-ClPhO- DBS, the average autodetachment lifetime of the 19'120'1/11'1 mode has been estimated to be ∼548 ± 108 ps. Observation of these exceptionally slow autodetachment rates of vibrational Feshbach resonances strongly indicates that the correlation effect may play a significant role in the DBS photodetachment dynamics. Fermi's golden rule has been invoked so that the correlation effect is taken into account in the form of the interaction between the charge and the induced dipole where the latter is given by the polarizable counterparts of the electron-rich halogenated compound and the diffuse non-valence electron. This report suggests that one may measure, from the real-time autodetachment dynamics, the extent of the correlation effect contribution to the stabilization and/or dynamics of the excess non-valence electron among many different types of long-range interactions of the DBS.
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Affiliation(s)
- Do Hyung Kang
- Department of Chemistry, KAIST Daejeon 34141 Republic of Korea
| | - Jinwoo Kim
- Department of Chemistry, KAIST Daejeon 34141 Republic of Korea
| | - Sang Kyu Kim
- Department of Chemistry, KAIST Daejeon 34141 Republic of Korea
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Narayanan S J J, Tripathi D, Dutta AK. Doorway Mechanism for Electron Attachment Induced DNA Strand Breaks. J Phys Chem Lett 2021; 12:10380-10387. [PMID: 34669407 DOI: 10.1021/acs.jpclett.1c02735] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
We report a new doorway mechanism for the dissociative electron attachment to genetic materials. The dipole-bound state of the nucleotide anion acts as the doorway for electron capture in the genetic material. The electron gets subsequently transferred to a dissociative σ*-type anionic state localized on a sugar-phosphate or a sugar-nucleobase bond, leading to their cleavage. The electron transfer is mediated by the mixing of electronic and nuclear degrees of freedom. The cleavage rate of the sugar-phosphate bond predicted by this new mechanism is higher than that of the sugar-nucleobase bond breaking, and both processes are considerably slower than the formation of a stable valence-bound anion. The new mechanism can explain the relative rates of electron attachment induced bond cleavages in genetic materials.
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Affiliation(s)
- Jishnu Narayanan S J
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Divya Tripathi
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Achintya Kumar Dutta
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
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10
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Dempwolff AL, Belogolova AM, Trofimov AB, Dreuw A. Intermediate state representation approach to physical properties of molecular electron-attached states: Theory, implementation, and benchmarking. J Chem Phys 2021; 154:104117. [PMID: 33722034 DOI: 10.1063/5.0043337] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Computational schemes for comprehensive studies of molecular electron-attached states and the calculation of electron affinities (EAs) are formulated and implemented employing the intermediate state representation (ISR) formalism and the algebraic-diagrammatic construction approximation for the electron propagator (EA-ADC). These EA-ADC(n)/ISR(m) schemes allow for a consistent treatment of not only electron affinities and pole strengths up to third-order of perturbation theory (n = 3) but also one-electron properties of electron-attached states up to second order (m = 2). The EA-ADC/ISR equations were implemented in the Q-Chem program for Ŝz-adapted intermediate states, allowing also open-shell systems to be studied using unrestricted Hartree-Fock references. For benchmarking of the EA-(U)ADC/ISR schemes, EAs and dipole moments of various electron-attached states of small closed- and open-shell molecules were computed and compared to full configuration interaction data. As an illustrative example, EA-ADC(3)/ISR(2) has been applied to the thymine-thymine (6-4) DNA photolesion.
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Affiliation(s)
- Adrian L Dempwolff
- Interdisciplinary Center for Scientific Computing, Heidelberg University, Im Neuenheimer Feld 205, D-69120 Heidelberg, Germany
| | - Alexandra M Belogolova
- Laboratory of Quantum Chemistry, Irkutsk State University, Karl Marx Street 1, 664003 Irkutsk, Russia
| | - Alexander B Trofimov
- Laboratory of Quantum Chemistry, Irkutsk State University, Karl Marx Street 1, 664003 Irkutsk, Russia
| | - Andreas Dreuw
- Interdisciplinary Center for Scientific Computing, Heidelberg University, Im Neuenheimer Feld 205, D-69120 Heidelberg, Germany
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11
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Abstract
We present an EOM-CCSD-based quantum mechanical/molecular mechanical (QM/MM) study on the electron attachment process to solvated cytosine. The electron attachment in the bulk solvated cytosine occurs through a doorway mechanism, where the initial electron is localized on water. The electron is subsequently transferred to cytosine by the mixing of electronic and nuclear degrees of freedom, which occurs on an ultrafast time scale. The bulk water environment stabilizes the cytosine-bound anion by an extensive hydrogen-bond network and drastically enhances the electron transfer rate from that observed in the gas phase. Microhydration studies cannot reproduce the effect of the bulk water environment on the electron attachment process, and one needs to include a large number of water molecules in the calculation to obtain converged results. The predicted adiabatic electron affinity and electron transfer rate obtained from our QM/MM calculations are consistent with the available experimental results.
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Affiliation(s)
- Pooja Verma
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Debashree Ghosh
- School of Chemical Sciences, Indian Association for the Cultivation of Science, Kolkata 700032, India
| | - Achintya Kumar Dutta
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
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12
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Banerjee S, Sokolov AY. Efficient implementation of the single-reference algebraic diagrammatic construction theory for charged excitations: Applications to the TEMPO radical and DNA base pairs. J Chem Phys 2021; 154:074105. [PMID: 33607870 DOI: 10.1063/5.0040317] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
We present an efficient implementation of the second- and third-order single-reference algebraic diagrammatic construction (ADC) theory for electron attachment and ionization energies and spectra [EA/IP-ADC(n), n = 2, 3]. Our new EA/IP-ADC program features spin adaptation for closed-shell systems, density fitting for efficient handling of the two-electron integral tensors, and vectorized and parallel implementation of tensor contractions. We demonstrate capabilities of our efficient implementation by applying the EA/IP-ADC(n) (n = 2, 3) methods to compute the photoelectron spectrum of the (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) radical, as well as the vertical and adiabatic electron affinities of TEMPO and two DNA base pairs (guanine-cytosine and adenine-thymine). The spectra and electron affinities computed using large diffuse basis sets with up to 1028 molecular orbitals are found to be in good agreement with the best available results from the experiment and theoretical simulations.
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Affiliation(s)
- Samragni Banerjee
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, USA
| | - Alexander Yu Sokolov
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, USA
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Mukherjee M, Tripathi D, Brehm M, Riplinger C, Dutta AK. Efficient EOM-CC-based Protocol for the Calculation of Electron Affinity of Solvated Nucleobases: Uracil as a Case Study. J Chem Theory Comput 2020; 17:105-116. [DOI: 10.1021/acs.jctc.0c00655] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
| | - Divya Tripathi
- Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Martin Brehm
- Institute of Chemistry, Martin Luther University Halle-Wittenberg, Von-Danckelmann-Platz 4, 06120 Halle (Saale), Germany
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Mukherjee M, Tripathi D, Dutta AK. Water mediated electron attachment to nucleobases: Surface-bound vs bulk solvated electrons. J Chem Phys 2020; 153:044305. [DOI: 10.1063/5.0010509] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Madhubani Mukherjee
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Divya Tripathi
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Achintya Kumar Dutta
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
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15
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Haldar S, Dutta AK. A Multilayer Approach to the Equation of Motion Coupled-Cluster Method for the Electron Affinity. J Phys Chem A 2020; 124:3947-3962. [DOI: 10.1021/acs.jpca.0c01793] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Soumi Haldar
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Achintya Kumar Dutta
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
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16
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Ranga S, Mukherjee M, Dutta AK. Interactions of Solvated Electrons with Nucleobases: The Effect of Base Pairing. Chemphyschem 2020; 21:1019-1027. [DOI: 10.1002/cphc.202000133] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 03/23/2020] [Indexed: 01/30/2023]
Affiliation(s)
- Santosh Ranga
- Department of ChemistryIndian Institute of Technology (IIT), Bombay Powai Maharastra 400076 India
| | - Madhubani Mukherjee
- Department of ChemistryIndian Institute of Technology (IIT), Bombay Powai Maharastra 400076 India
| | - Achintya Kumar Dutta
- Department of ChemistryIndian Institute of Technology (IIT), Bombay Powai Maharastra 400076 India
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17
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Anusiewicz I, Skurski P, Simons J. Fate of Dipole-Bound Anion States when Hydrated. J Phys Chem A 2020; 124:2064-2076. [PMID: 32065750 DOI: 10.1021/acs.jpca.0c00360] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Many strongly polar molecules can form an anion by attaching an electron to either an empty or half-filled valence-bound (VB) orbital or a so-called dipole-bound (DB) orbital. These two families of orbitals can be very different in their radial extent (the former are usually more compact, while the latter are quite diffuse) and in the degree to which they are affected by surrounding solvent molecules. In this study, the effects of hydration (representative of strong solvation) on the DB state of a model polar species are investigated with an eye toward determining whether this state is stabilized or even persists when a few to 100 water molecules surround the polar molecule. It is found that in the presence of up to ca. 10-12 water molecules, the excess electron can remain in a DB orbital. However, once there are enough water molecules to form a complete first hydration shell (or more), the excess electron migrates into an orbital localized on the outer surface of the water solvent cage. These findings have implications on the possible role of DB states as doorways to facilitating electron attachment and subsequent electron transfer to VB states. It is shown that even when the electron is bound to the surface of the surrounding solvent, the dipole potential of the solute molecule can influence where on the surface the electron binds. It is also illustrated that using continuum dielectric methods to describe the hydration of DB states is fraught with danger because much of the outermost electron density in such states penetrates outside the boundary of the cavity used in these methods.
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Affiliation(s)
- Iwona Anusiewicz
- Laboratory of Quantum Chemistry, Faculty of Chemistry, University of Gdańsk, Wita Stwosza 63, 80-308 Gdańsk, Poland
| | - Piotr Skurski
- Laboratory of Quantum Chemistry, Faculty of Chemistry, University of Gdańsk, Wita Stwosza 63, 80-308 Gdańsk, Poland.,Henry Eyring Center for Theoretical Chemistry, Department of Chemistry, University of Utah, Salt Lake City, Utah 84112, United States
| | - Jack Simons
- Henry Eyring Center for Theoretical Chemistry, Department of Chemistry, University of Utah, Salt Lake City, Utah 84112, United States
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