1
|
Jones LO, Schatz GC. Excited State Nonadiabatic Molecular Dynamics of Hot Electron Addition to Water Clusters in the Ultrafast Femtosecond Regime. J Phys Chem Lett 2023; 14:3521-3526. [PMID: 37014704 DOI: 10.1021/acs.jpclett.3c00386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Dissociative electron attachment (DEA) reactions of water result in the production of hydrogen atoms and hydroxide anions. This has been studied for a long time and is relatively slow in liquid water for thermalized hydrated electrons but much faster with a higher-energy electron. Here, we probe the nonadiabatic molecular dynamics after the addition of a hot electron (6-7 eV) to a neutral water cluster (H2O)n, where n = 2-12, considering the 0-100 fs time scale using the fewest switches surface hopping method, in conjunction with ab initio molecular dynamics and the Tamm-Dancoff approximation density functional theory method. The nonadiabatic DEA occurs within 10-60 fs, and with high probability, giving H + OH- above an energy threshold. This is faster than time scales estimated previously for autoionization or adiabatic DEA. The change in threshold energy with cluster size is modest, ranging from 6.6 to 6.9 eV. Dissociation on a femtosecond time scale is consistent with pulsed radiolysis experiments.
Collapse
Affiliation(s)
- Leighton O Jones
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - George C Schatz
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| |
Collapse
|
2
|
Yamamoto YI, Suzuki T. Distortion Correction of Low-Energy Photoelectron Spectra of Liquids Using Spectroscopic Data for Solvated Electrons. J Phys Chem A 2023; 127:2440-2452. [PMID: 36917090 DOI: 10.1021/acs.jpca.2c08046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023]
Abstract
Time-resolved photoelectron spectroscopy (TRPES) enables real-time observation of ultrafast electronic dynamics in solutions. When extreme ultraviolet (EUV) probe pulses are employed, they can ionize solutes from all electronic states involved in the dynamics. However, EUV pulses also produce a strong ionization signal from a solvent that is typically 6 orders of magnitude greater than the pump-probe photoelectron signal of solutes. Alternatively, UV probe pulses enable highly sensitive and selective observation of photoexcited solutes because typical solvents such as water are transparent to UV radiation. An obstacle in such UV-TRPES measurements is spectral distortion caused by electron scattering and a yet to be identified mechanism in liquids. We have previously proposed the spectral retrieval (SR) method as an a posteriori approach to removing the distortion and overcoming this difficulty in UV-TRPES; however, its accuracy has not yet been verified by comparison with EUV-TRPES results. In the present study, we perform EUV-TRPES for charge transfer reactions in water, methanol, and ethanol, and verify SR analysis of UV-TRPES. We also estimate a previously undetermined energy-dependent intensity factor and expand the basis sets for SR analysis. The refined SR method is employed for reanalyzing the UV-TRPES data for the formation and relaxation dynamics of solvated electrons in various systems. The electron binding energy distributions for solvated electrons in liquid water, methanol, and ethanol are confirmed to be Gaussian centered at 3.78, 3.39, and 3.25 eV, respectively, in agreement with Nishitani et al. [ Sci. Adv. 2019, 5(8), eaaw6896]. An effective energy gap between the conduction band and the vacuum level at the gas-liquid interface is estimated to be 0.2 eV for liquid water and 0.1 eV for methanol and ethanol.
Collapse
Affiliation(s)
- Yo-Ichi Yamamoto
- Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-Ku, Kyoto 606-8502, Japan
| | - Toshinori Suzuki
- Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-Ku, Kyoto 606-8502, Japan
| |
Collapse
|
3
|
Heim ZN, Neumark DM. Nonadiabatic Dynamics Studied by Liquid-Jet Time-Resolved Photoelectron Spectroscopy. Acc Chem Res 2022; 55:3652-3662. [PMID: 36480155 DOI: 10.1021/acs.accounts.2c00609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The development of the liquid microjet technique by Faubel and co-workers has enabled the investigation of high vapor pressure liquids and solutions utilizing high-vacuum methods. One such method is photoelectron spectroscopy (PES), which allows one to probe the electronic properties of a sample through ionization in a state-specific manner. Liquid microjets consisting of pure solvents and solute-solvent systems have been studied with great success utilizing PES and, more recently, time-resolved PES (TRPES). Here, we discuss progress made over recent years in understanding the solvation and excited state dynamics of the solvated electron and nucleic acid constituents (NACs) using these methods, as well as the prospect for their future.The solvated electron is of particular interest in liquid microjet experiments as it represents the simplest solute system. Despite this simplicity, there were still many unresolved questions about its binding energy and excited state relaxation dynamics that are ideal problems for liquid microjet PES. In the work discussed in this Account, accurate binding energies were measured for the solvated electron in multiple high vapor pressure solvents. The advantages of liquid jet PES were further highlighted in the femtosecond excited state relaxation studies on the solvated electron in water where a 75 ± 20 fs lifetime attributable to internal conversion from the excited p-state to a hot ground state was measured, supporting a nonadiabatic relaxation mechanism.Nucleic acid constituents represent a class of important solutes with several unresolved questions that the liquid microjet PES method is uniquely suited to address. As TRPES is capable of tracking dynamics with state-specificity, it is ideal for instances where there are multiple excited states potentially involved in the dynamics. Time-resolved studies of NAC relaxation after excitation using ultraviolet light identified relaxation lifetimes from multiple excited states. The state-specific nature of the TRPES method allowed us to identify the lack of any signal attributable to the 1nπ* state in thymine derived NACs. The femtosecond time resolution of the technique also aided in identifying differences between the excited state lifetimes of thymidine and thymidine monophosphate. These have been interpreted, aided by molecular dynamics simulations, as an influence of conformational differences leading to a longer excited state lifetime in thymidine monophosphate.Finally, we discuss advances in tabletop light sources extending into the extreme ultraviolet and soft X-ray regimes that allow expansion of liquid jet TRPES to full valence band and potentially core level studies of solutes and pure liquids in liquid microjets. As most solutes have ground state binding energies in the range of 10 eV, observation of both excited state decay and ground state recovery using ultraviolet pump-ultraviolet probe TRPES has been intractable. With high-harmonic generation light sources, it will be possible to not only observe complete relaxation pathways for valence level dynamics but to also track dynamics with element specificity by probing core levels of the solute of interest.
Collapse
Affiliation(s)
- Zachary N Heim
- Department of Chemistry, University of California, Berkeley, California94720, United States
| | - Daniel M Neumark
- Department of Chemistry, University of California, Berkeley, California94720, United States.,Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California94720, United States
| |
Collapse
|
4
|
Low PJ, Chu W, Nie Z, Bin Mohd Yusof MS, Prezhdo OV, Loh ZH. Observation of a transient intermediate in the ultrafast relaxation dynamics of the excess electron in strong-field-ionized liquid water. Nat Commun 2022; 13:7300. [DOI: 10.1038/s41467-022-34981-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 11/11/2022] [Indexed: 11/28/2022] Open
Abstract
AbstractA unified picture of the electronic relaxation dynamics of ionized liquid water has remained elusive despite decades of study. Here, we employ sub-two-cycle visible to short-wave infrared pump-probe spectroscopy and ab initio nonadiabatic molecular dynamics simulations to reveal that the excess electron injected into the conduction band (CB) of ionized liquid water undergoes sequential relaxation to the hydrated electron s ground state via an intermediate state, identified as the elusive p excited state. The measured CB and p-electron lifetimes are 0.26 ± 0.02 ps and 62 ± 10 fs, respectively. Ab initio quantum dynamics yield similar lifetimes and furthermore reveal vibrational modes that participate in the different stages of electronic relaxation, with initial relaxation within the dense CB manifold coupled to hindered translational motions whereas subsequent p-to-s relaxation facilitated by librational and even intramolecular bending modes of water. Finally, energetic considerations suggest that a hitherto unobserved trap state resides ~0.3-eV below the CB edge of liquid water. Our results provide a detailed atomistic picture of the electronic relaxation dynamics of ionized liquid water with unprecedented time resolution.
Collapse
|
5
|
Bin Mohd Yusof MS, Song H, Debnath T, Lowe B, Yang M, Loh ZH. Ultrafast proton transfer of the aqueous phenol radical cation. Phys Chem Chem Phys 2022; 24:12236-12248. [PMID: 35579397 DOI: 10.1039/d2cp00505k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Proton transfer (PT) reactions are fundamental to numerous chemical and biological processes. While sub-picosecond PT involving electronically excited states has been extensively studied, little is known about ultrafast PT triggered by photoionization. Here, we employ femtosecond optical pump-probe spectroscopy and quantum dynamics calculations to investigate the ultrafast proton transfer dynamics of the aqueous phenol radical cation (PhOH˙+). Analysis of the vibrational wave packet dynamics reveals unusually short dephasing times of 0.18 ± 0.02 ps and 0.16 ± 0.02 ps for the PhOH˙+ O-H wag and bend frequencies, respectively, suggestive of ultrafast PT occurring on the ∼0.1 ps timescale. The reduced potential energy surface obtained from ab initio calculations shows that PT is barrierless when it is coupled to the intermolecular hindered translation between PhOH˙+ and the proton-acceptor water molecule. Quantum dynamics calculations yield a lifetime of 193 fs for PhOH˙+, in good agreement with the experimental results and consistent with the PT reaction being mediated by the intermolecular O⋯O stretch. These results suggest that photoionization can be harnessed to produce photoacids that undergo ultrafast PT. In addition, they also show that PT can serve as an ultrafast deactivation channel for limiting the oxidative damage potential of radical cations.
Collapse
Affiliation(s)
- Muhammad Shafiq Bin Mohd Yusof
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore.
| | - Hongwei Song
- State Key Laboratory for Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, China
| | - Tushar Debnath
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore.
| | - Bethany Lowe
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore.
| | - Minghui Yang
- State Key Laboratory for Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, China.,Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430071, China
| | - Zhi-Heng Loh
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore.
| |
Collapse
|
6
|
Ahmadi S. Hydrated electrons and cluster science. J Mol Struct 2022. [DOI: 10.1016/j.molstruc.2021.131898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
7
|
Bin Mohd Yusof MS, Debnath T, Loh ZH. Observation of intra- and intermolecular vibrational coherences of the aqueous tryptophan radical induced by photodetachment. J Chem Phys 2021; 155:134306. [PMID: 34624987 DOI: 10.1063/5.0067335] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The study of the photodetachment of amino acids in aqueous solution is pertinent to the understanding of elementary processes that follow the interaction of ionizing radiation with biological matter. In the case of tryptophan, the tryptophan radical that is produced by electron ejection also plays an important role in numerous redox reactions in biology, although studies of its ultrafast molecular dynamics are limited. Here, we employ femtosecond optical pump-probe spectroscopy to elucidate the ultrafast structural rearrangement dynamics that accompany the photodetachment of the aqueous tryptophan anion by intense, ∼5-fs laser pulses. The observed vibrational wave packet dynamics, in conjunction with density functional theory calculations, identify the vibrational modes of the tryptophan radical, which participate in structural rearrangement upon photodetachment. Aside from intramolecular vibrational modes, our results also point to the involvement of intermolecular modes that drive solvent reorganization about the N-H moiety of the indole sidechain. Our study offers new insight into the ultrafast molecular dynamics of ionized biomolecules and suggests that the present experimental approach can be extended to investigate the photoionization- or photodetachment-induced structural dynamics of larger biomolecules.
Collapse
Affiliation(s)
- Muhammad Shafiq Bin Mohd Yusof
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore
| | - Tushar Debnath
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore
| | - Zhi-Heng Loh
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore
| |
Collapse
|
8
|
Bin Mohd Yusof MS, Lim YL, Loh ZH. Ultrafast vibrational wave packet dynamics of the aqueous tyrosyl radical anion induced by photodetachment. Phys Chem Chem Phys 2021; 23:18525-18534. [PMID: 34581329 DOI: 10.1039/d1cp02975d] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The ultrafast dynamics triggered by the photodetachment of the tyrosinate dianion in aqueous environment shed light on the elementary processes that accompany the interaction of ionizing radiation with biological matter. Photodetachment of the tryosinate dianion yields the tyrosyl radical anion, an important intermediate in biological redox reactions, although the study of its ultrafast dynamics is limited. Here, we utilize femtosecond optical pump-probe spectroscopy to investigate the ultrafast structural reorganization dynamics that follow the photodetachment of the tyrosinate dianion in aqueous solution. Photodetachment of the tyrosinate dianion leads to vibrational wave packet motion along seven vibrational modes that are coupled to the photodetachment process. The vibrational modes are assigned with the aid of density functional theory (DFT) calculations. Our results offer a glimpse of the elementary dynamics of ionized biomolecules and suggest the possibility of extending this approach to investigate the ionization-induced structural rearrangement of other aromatic amino acids and larger biomolecules.
Collapse
Affiliation(s)
- Muhammad Shafiq Bin Mohd Yusof
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore.
| | - Yong Liang Lim
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore.
| | - Zhi-Heng Loh
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore.
| |
Collapse
|
9
|
Sakakibara N, Ito T, Terashima K, Hakuta Y, Miura E. Dynamics of solvated electrons during femtosecond laser-induced plasma generation in water. Phys Rev E 2020; 102:053207. [PMID: 33327104 DOI: 10.1103/physreve.102.053207] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 10/16/2020] [Indexed: 11/07/2022]
Abstract
We studied the dynamics of solvated electrons in the early stage of plasma generation in water induced with an intense femtosecond laser pulse. According to the decay kinetics of solvated electrons, a fast recombination process of solvated electrons (geminate recombination) occurred with a more prolonged lifetime (500 ps to 1 ns) than that observed in previous pulse photolysis studies (10-100 ps). This unusually longer lifetime is attributed to additional production of solvated electrons due to abundant free electrons generated with the laser-induced plasma, implying significant influence of free electrons on the dynamics of solvated electrons.
Collapse
Affiliation(s)
- Noritaka Sakakibara
- Department of Advanced Materials Science, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561, Japan.,AIST-UTokyo Advanced Operando-Measurement Technology Open Innovation Laboratory (OPERANDO-OIL), National Institute of Advanced Industrial Science and Technology (AIST), 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8589, Japan
| | - Tsuyohito Ito
- Department of Advanced Materials Science, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561, Japan.,AIST-UTokyo Advanced Operando-Measurement Technology Open Innovation Laboratory (OPERANDO-OIL), National Institute of Advanced Industrial Science and Technology (AIST), 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8589, Japan
| | - Kazuo Terashima
- Department of Advanced Materials Science, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561, Japan.,AIST-UTokyo Advanced Operando-Measurement Technology Open Innovation Laboratory (OPERANDO-OIL), National Institute of Advanced Industrial Science and Technology (AIST), 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8589, Japan
| | - Yukiya Hakuta
- AIST-UTokyo Advanced Operando-Measurement Technology Open Innovation Laboratory (OPERANDO-OIL), National Institute of Advanced Industrial Science and Technology (AIST), 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8589, Japan
| | - Eisuke Miura
- AIST-UTokyo Advanced Operando-Measurement Technology Open Innovation Laboratory (OPERANDO-OIL), National Institute of Advanced Industrial Science and Technology (AIST), 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8589, Japan
| |
Collapse
|
10
|
Affiliation(s)
- Toshinori Suzuki
- Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-Ku, Kyoto 606-8502,
Japan
| |
Collapse
|
11
|
Karashima S, Yamamoto YI, Suzuki T. Ultrafast Internal Conversion and Solvation of Electrons in Water, Methanol, and Ethanol. J Phys Chem Lett 2019; 10:4499-4504. [PMID: 31343891 DOI: 10.1021/acs.jpclett.9b01750] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Ultrafast internal conversion from the first excited state of a solvated electron in water, methanol, and ethanol is investigated using time-resolved photoelectron spectroscopy of liquid microjets and a spectral retrieval method. Photoelectron spectra corrected for inelastic scattering clearly reveal well-separated signals from the excited and ground states, and the latter enables us to analyze the solvation dynamics in the ground state after internal conversion. Measurements with 25 fs time resolution identify a rapid increase in the vertical electron binding energy of the solvated electron owing to nuclear wave packet motions in the excited state and allow us to precisely determine the internal conversion time.
Collapse
Affiliation(s)
- Shutaro Karashima
- Department of Chemistry, Graduate School of Science , Kyoto University , Kitashirakawa-Oiwakecho, Sakyo-Ku, Kyoto 606-8502 , Japan
| | - Yo-Ichi Yamamoto
- Department of Chemistry, Graduate School of Science , Kyoto University , Kitashirakawa-Oiwakecho, Sakyo-Ku, Kyoto 606-8502 , Japan
| | - Toshinori Suzuki
- Department of Chemistry, Graduate School of Science , Kyoto University , Kitashirakawa-Oiwakecho, Sakyo-Ku, Kyoto 606-8502 , Japan
| |
Collapse
|
12
|
Nishitani J, Yamamoto YI, West CW, Karashima S, Suzuki T. Binding energy of solvated electrons and retrieval of true UV photoelectron spectra of liquids. SCIENCE ADVANCES 2019; 5:eaaw6896. [PMID: 31497644 PMCID: PMC6716956 DOI: 10.1126/sciadv.aaw6896] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Accepted: 07/24/2019] [Indexed: 05/24/2023]
Abstract
The electronic energy and dynamics of solvated electrons, the simplest yet elusive chemical species, is of interest in chemistry, physics, and biology. Here, we present the electron binding energy distributions of solvated electrons in liquid water, methanol, and ethanol accurately measured using extreme ultraviolet (EUV) photoelectron spectroscopy of liquids with a single-order high harmonic. The distributions are Gaussian in all cases. Using the EUV and UV photoelectron spectra of solvated electrons, we succeeded in retrieving sharp electron kinetic energy distributions from the spectra broadened and energy shifted by inelastic scattering in liquids, overcoming an obstacle in ultrafast UV photoelectron spectroscopy of liquids. The method is demonstrated for the benchmark systems of charge transfer to solvent reaction and ultrafast internal conversion of hydrated electron from the first excited state.
Collapse
|
13
|
Abstract
A cavity or excluded-volume structure best explains the experimental properties of the aqueous or “hydrated” electron.
Collapse
Affiliation(s)
- John M. Herbert
- Department of Chemistry & Biochemistry
- The Ohio State University
- Columbus
- USA
| |
Collapse
|
14
|
Farr EP, Zho CC, Challa JR, Schwartz BJ. Temperature dependence of the hydrated electron’s excited-state relaxation. II. Elucidating the relaxation mechanism through ultrafast transient absorption and stimulated emission spectroscopy. J Chem Phys 2017; 147:074504. [DOI: 10.1063/1.4985906] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Affiliation(s)
- Erik P. Farr
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095-1569, USA
| | - Chen-Chen Zho
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095-1569, USA
| | - Jagannadha R. Challa
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095-1569, USA
| | - Benjamin J. Schwartz
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095-1569, USA
| |
Collapse
|
15
|
Zho CC, Farr EP, Glover WJ, Schwartz BJ. Temperature dependence of the hydrated electron’s excited-state relaxation. I. Simulation predictions of resonance Raman and pump-probe transient absorption spectra of cavity and non-cavity models. J Chem Phys 2017; 147:074503. [DOI: 10.1063/1.4985905] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Affiliation(s)
- Chen-Chen Zho
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California,
90095-1569, USA
| | - Erik P. Farr
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California,
90095-1569, USA
| | - William J. Glover
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California,
90095-1569, USA
- NYU-ECNU Center for Computational Chemistry at NYU Shanghai, Shanghai 200062, China
- NYU Shanghai, 1555 Century Avenue,
Shanghai 200135, China
| | - Benjamin J. Schwartz
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California,
90095-1569, USA
| |
Collapse
|
16
|
Borgis D, Rossky PJ, Turi L. Electronic Excited State Lifetimes of Anionic Water Clusters: Dependence on Charge Solvation Motif. J Phys Chem Lett 2017; 8:2304-2309. [PMID: 28475840 DOI: 10.1021/acs.jpclett.7b00555] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
An ongoing controversy about water cluster anions concerns the electron-binding motif, whether the charge center is localized at the surface or within the cluster interior. Here, mixed quantum-classical dynamics simulations have been carried out for a wide range of cluster sizes (n ≤ 1000) for (H2O)n- and (D2O)n-, based on a nonequilibrium first-order rate constant approach. The computed data are in good general agreement with time-resolved photoelectron imaging results (n ≤ 200). The analysis reveals that, for surface state electrons, the cluster size dependence of the excited state electronic energy gap and the magnitude of the nonadiabatic couplings have compensating influences on the excited state lifetimes: the excited state lifetime for surface states reaches a minimum for n ∼ 150 and then increases for larger clusters. It is concluded that the electron resides in a surface-localized motif in all of these measured clusters, dominating at least up to n = 200.
Collapse
Affiliation(s)
- Daniel Borgis
- Pôle de Chimie Théorique, UMR-CNRS PASTEUR, Ecole Normale Supérieure, 24, rue Lhomond, 75231 Paris Cedex 05, France
| | - Peter J Rossky
- Department of Chemistry, Rice University , P.O. Box 1892, MS-60, Houston, Texas 77251-1892, United States
| | - László Turi
- Department of Physical Chemistry, ELTE Eötvös Loránd University , Budapest 112, P.O. Box 32, H-1518 Budapest, Hungary
| |
Collapse
|
17
|
Zho CC, Schwartz BJ. Time-Resolved Photoelectron Spectroscopy of the Hydrated Electron: Comparing Cavity and Noncavity Models to Experiment. J Phys Chem B 2016; 120:12604-12614. [PMID: 27973828 DOI: 10.1021/acs.jpcb.6b07852] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Chen-Chen Zho
- Department of Chemistry and
Biochemistry University of California, Los Angeles, Los Angeles, California 90095-1569, United States
| | - Benjamin J. Schwartz
- Department of Chemistry and
Biochemistry University of California, Los Angeles, Los Angeles, California 90095-1569, United States
| |
Collapse
|
18
|
Elkins MH, Williams HL, Neumark DM. Isotope effect on hydrated electron relaxation dynamics studied with time-resolved liquid jet photoelectron spectroscopy. J Chem Phys 2016; 144:184503. [DOI: 10.1063/1.4948546] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Madeline H. Elkins
- Department of Chemistry, University of California, Berkeley, California 94720, USA
| | - Holly L. Williams
- Department of Chemistry, University of California, Berkeley, California 94720, USA
| | - Daniel M. Neumark
- Department of Chemistry, University of California, Berkeley, California 94720, USA
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| |
Collapse
|
19
|
Karashima S, Yamamoto YI, Suzuki T. Resolving Nonadiabatic Dynamics of Hydrated Electrons Using Ultrafast Photoemission Anisotropy. PHYSICAL REVIEW LETTERS 2016; 116:137601. [PMID: 27082002 DOI: 10.1103/physrevlett.116.137601] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2015] [Indexed: 05/05/2023]
Abstract
We have studied ultrafast nonadiabatic dynamics of excess electrons trapped in the band gap of liquid water using time- and angle-resolved photoemission spectroscopy. Anisotropic photoemission from the first excited state was discovered, which enabled unambiguous identification of nonadiabatic transition to the ground state in 60 fs in H_{2}O and 100 fs in D_{2}O. The photoelectron kinetic energy distribution exhibited a rapid spectral shift in ca. 20 fs, which is ascribed to the librational response of a hydration shell to electronic excitation. Photoemission anisotropy indicates that the electron orbital in the excited state is depolarized in less than 40 fs.
Collapse
Affiliation(s)
- Shutaro Karashima
- Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-Ku, 606-8502 Kyoto, Japan
| | - Yo-Ichi Yamamoto
- Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-Ku, 606-8502 Kyoto, Japan
| | - Toshinori Suzuki
- Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-Ku, 606-8502 Kyoto, Japan
| |
Collapse
|
20
|
Meyer M, Agarwal I, Wolf M, Bovensiepen U. Ultrafast electron dynamics at water covered alkali adatoms adsorbed on Cu(111). Phys Chem Chem Phys 2015; 17:8441-8. [PMID: 25639630 DOI: 10.1039/c4cp05356g] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Here we report on the ultrafast electron dynamics of the alkalis Na, K, and Cs coadsorbed with D2O on Cu(111) surfaces, which we investigated with femtosecond time-resolved two-photon photoemission. The well known transient electronic binding energy stabilization in bare adsorbed alkalis is enhanced by the presence of water which acts as a solvent and increases the transient energy gain. We observe for all adsorbed alkalis a transient binding energy stabilization of 100-300 meV. The stabilization rates range from 1 to 2 eV ps(-1). Here the heavier alkali exhibits a slower stabilization which we explain by their weaker static alkali-water interaction observed in thermal desorption spectroscopy. The population dynamics at low water coverage is described by a single exponential. With increasing water coverage the behavior becomes non-exponential suggesting an additional excited state due to electron solvation.
Collapse
Affiliation(s)
- Michael Meyer
- Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| | | | | | | |
Collapse
|
21
|
Men Z, Fang W, Li Z, Sun C, Li Z, Wang X. Hydrated-electron resonance enhancement O-H stretching vibration of water hexamer at air-water interface. OPTICS LETTERS 2015; 40:1434-1437. [PMID: 25831351 DOI: 10.1364/ol.40.001434] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Raman scattering of the O-H stretching vibration mode inside water, as well as near and at the air-water interface, was investigated by laser-induced breakdown (LIB). An intense and characteristic higher wavenumber Raman shift of the O-H vibration was observed at the air-water interface, which was attributed to the hydrated-electron resonance enhancement of the O-H stretching vibration mode of water hexamer. The hydrated electron in the water hexamer structure was formed by excess electrons injected into the gas-like phase with low hydrogen bond order under LIB. The electron-phonon coupled mechanism was discussed.
Collapse
|
22
|
Abstract
Solvated electrons were first discovered in solutions of metals in liquid ammonia. The physical and chemical properties of these species have been studied extensively for many decades using an arsenal of electrochemical, spectroscopic, and theoretical techniques. Yet, in contrast to their hydrated counterpart, the ultrafast dynamics of ammoniated electrons remained completely unexplored until quite recently. Femtosecond pump-probe spectroscopy on metal-ammonia solutions and femtosecond multiphoton ionization spectroscopy on the neat ammonia solvent have provided new insights into the optical properties and the reactivities of this fascinating species. This article reviews the nature of the optical transition, which gives the metal-ammonia solutions their characteristic blue appearance, in terms of ultrafast relaxation processes involving bound and continuum excited states. The recombination processes following the injection of an electron via photoionization of the solvent are discussed in the context of the electronic structure of the liquid and the anionic defect associated with the solvated electron.
Collapse
Affiliation(s)
- Peter Vöhringer
- Institut für Physikalische und Theoretische Chemie, Rheinische Friedrich-Wilhelms-Universität, 53115 Bonn, Germany;
| |
Collapse
|
23
|
Müller JP, Zhavoronkov N, Hertel IV, Schulz CP. Time-resolved excited state energetics of the solvated electron in sodium-doped water clusters. J Phys Chem A 2014; 118:8517-24. [PMID: 24936724 DOI: 10.1021/jp502238c] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The energetics and dynamics of the first electronically excited state of solvated electron in sodium-doped water clusters has been studied, by means of time-resolved electron spectra created in a pump-probe fs-laser experiment. The Na ··· (H2O)n clusters were excited by pulses at a wavelength of 795 nm, while ionization was achieved at a wavelength of 398 nm, and the overall cross-correlation fwhm was about 50 fs. Mass-resolved electron spectra were taken using photoelectron-photoion coincidence (PEPICO) spectroscopy for cluster sizes ranging from n = 1 up to 22. The electron spectra give new insights into the dynamics of the excited state of solvated electrons in Na ··· (H2O)n clusters. These dynamics are compared to known results for water cluster anions. In both cases, the observed dynamics are a combination of solvent rearrangement and internal energy conversion.
Collapse
Affiliation(s)
- J P Müller
- Max-Born-Institute , Max-Born-Strasse 2a, 12489 Berlin, Germany
| | | | | | | |
Collapse
|
24
|
Elkins MH, Williams HL, Shreve AT, Neumark DM. Relaxation mechanism of the hydrated electron. Science 2014; 342:1496-9. [PMID: 24357314 DOI: 10.1126/science.1246291] [Citation(s) in RCA: 102] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The relaxation dynamics of the photoexcited hydrated electron have been subject to conflicting interpretations. Here, we report time-resolved photoelectron spectra of hydrated electrons in a liquid microjet with the aim of clarifying ambiguities from previous experiments. A sequence of three ultrashort laser pulses (~100 femtosecond duration) successively created hydrated electrons by charge-transfer-to-solvent excitation of dissolved anions, electronically excited these electrons via the s→p transition, and then ejected them into vacuum. Two distinct transient signals were observed. One was assigned to the initially excited p-state with a lifetime of ~75 femtoseconds, and the other, with a lifetime of ~400 femtoseconds, was attributed to s-state electrons just after internal conversion in a nonequilibrated solvent environment. These assignments support the nonadiabatic relaxation model.
Collapse
Affiliation(s)
- Madeline H Elkins
- Department of Chemistry, University of California, Berkeley, CA 94720, USA
| | | | | | | |
Collapse
|
25
|
Turi L, Rossky PJ. Theoretical studies of spectroscopy and dynamics of hydrated electrons. Chem Rev 2012; 112:5641-74. [PMID: 22954423 DOI: 10.1021/cr300144z] [Citation(s) in RCA: 129] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- László Turi
- Department of Physical Chemistry, Eötvös Loránd University, Budapest, Hungary.
| | | |
Collapse
|
26
|
Affiliation(s)
- Ryan M. Young
- Department of Chemistry, University of California, Berkeley, California 94720,
United States
| | - Daniel M. Neumark
- Department of Chemistry, University of California, Berkeley, California 94720,
United States
- Chemical
Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California
94720, United States
| |
Collapse
|
27
|
Buchner F, Schultz T, Lübcke A. Solvated electrons at the water-air interface: surface versus bulk signal in low kinetic energy photoelectron spectroscopy. Phys Chem Chem Phys 2012; 14:5837-42. [PMID: 22414952 DOI: 10.1039/c2cp23305c] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Time-resolved photoelectron spectroscopy at low kinetic energies (≲5 eV) is applied to dilute iodide solutions with different surface and bulk contributions. The results indicate a pronounced surface sensitivity. Signals assigned to solvated electrons near the liquid surface decay rapidly on a sub-ps timescale. In contrast to the literature, a long-lived surface solvated electron at 1.6 eV binding energy is not observed.
Collapse
Affiliation(s)
- Franziska Buchner
- Max-Born Institut für nichtlineare Optik und Kurzzeitspektroskopie, Max-Born-Str. 2A, 12489 Berlin, Germany
| | | | | |
Collapse
|
28
|
Venkataraman C. Semiclassical study of quantum coherence and isotope effects in ultrafast electron transfer reactions coupled to a proton and a phonon bath. J Chem Phys 2011; 135:204503. [DOI: 10.1063/1.3662095] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
|
29
|
Yonehara T, Hanasaki K, Takatsuka K. Fundamental Approaches to Nonadiabaticity: Toward a Chemical Theory beyond the Born–Oppenheimer Paradigm. Chem Rev 2011; 112:499-542. [DOI: 10.1021/cr200096s] [Citation(s) in RCA: 154] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Takehiro Yonehara
- Department of Basic Sciences, Graduate School of Arts and Sciences, The University of Tokyo Komaba, 153-8902 Tokyo, Japan
| | - Kota Hanasaki
- Department of Basic Sciences, Graduate School of Arts and Sciences, The University of Tokyo Komaba, 153-8902 Tokyo, Japan
| | - Kazuo Takatsuka
- Department of Basic Sciences, Graduate School of Arts and Sciences, The University of Tokyo Komaba, 153-8902 Tokyo, Japan
| |
Collapse
|
30
|
Fischer MK, Rossmadl H, Iglev H. Novel geminate recombination channel after indirect photoionization of water. J Chem Phys 2011; 134:214507. [PMID: 21663367 DOI: 10.1063/1.3597776] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
We studied the photolysis of neat protonated and heavy water using pump-probe and pump-repump-probe spectroscopy. A novel recombination channel is reported leading to ultrafast quenching (0.7 ± 0.1 ps) of almost one third of the initial number of photo-generated electrons. The efficiency and the recombination rate of this channel are lower in heavy water, 27 ± 5% and (0.9 ± 0.1 ps)(-1), respectively. Comparison with similar data measured after photodetachment of aqueous hydroxide provides evidence for the formation of short-lived OH:e(-) (OD:e(-)) pairs after indirect photoionization of water at 9.2 eV.
Collapse
Affiliation(s)
- Martin K Fischer
- Physik-Department E 11, Technische Universität München, D-85748 Garching, Germany
| | | | | |
Collapse
|
31
|
Siefermann KR, Abel B. The Hydrated Electron: A Seemingly Familiar Chemical and Biological Transient. Angew Chem Int Ed Engl 2011; 50:5264-72. [DOI: 10.1002/anie.201006521] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2010] [Revised: 02/15/2011] [Indexed: 11/05/2022]
|
32
|
Siefermann KR, Abel B. Das hydratisierte Elektron - eine scheinbar vertraute transiente Spezies in chemischen und biologischen Systemen. Angew Chem Int Ed Engl 2011. [DOI: 10.1002/ange.201006521] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
33
|
Torres-Alacan J, Kratz S, Vöhringer P. Independent pairs and Monte-Carlo simulations of the geminate recombination of solvated electrons in liquid-to-supercritical water. Phys Chem Chem Phys 2011; 13:20806-19. [DOI: 10.1039/c1cp21678c] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
34
|
Tachikawa H. Electron Capture Dynamics of a Water Molecule Connected to a Cyclic Water Trimer: A Direct Ab Initio MD Approach. J Phys Chem A 2010; 114:10309-14. [DOI: 10.1021/jp105731u] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Hiroto Tachikawa
- Division of Materials Chemistry, Graduate School of Engineering, Hokkaido University, Sapporo 060-8628, Japan
| |
Collapse
|
35
|
Affiliation(s)
- Ross E Larsen
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095-1569, USA.
| | | | | |
Collapse
|
36
|
|
37
|
|
38
|
Liu HT, Müller JP, Zhavoronkov N, Schulz CP, Hertel IV. Ultrafast Dynamics in Na-Doped Water Clusters and the Solvated Electron. J Phys Chem A 2009; 114:1508-13. [DOI: 10.1021/jp907835z] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- H. T. Liu
- Max Born Institute, Max-Born-Strasse 2a, 12489 Berlin, Germany
| | - J. P. Müller
- Max Born Institute, Max-Born-Strasse 2a, 12489 Berlin, Germany
| | - N. Zhavoronkov
- Max Born Institute, Max-Born-Strasse 2a, 12489 Berlin, Germany
| | - C. P. Schulz
- Max Born Institute, Max-Born-Strasse 2a, 12489 Berlin, Germany
| | - I. V. Hertel
- Max Born Institute, Max-Born-Strasse 2a, 12489 Berlin, Germany
| |
Collapse
|
39
|
Fischer SF, Dietz W. Long Range Nonadiabatic Couplings and the Cluster-Size Dependence of the Lifetime of Excited Hydrated Electrons. ACTA ACUST UNITED AC 2009. [DOI: 10.1524/zpch.2007.221.5.585] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The recently observed linear dependence of the lifetime of excited hydrated electrons upon the inverse of the cluster size is explained in terms of a nonadiabatic long range coupling mechanism. It is due to dipolar interactions between the p→s transition and the excitation of the infrared active modes of the solvent water molecules.
Collapse
|
40
|
Abstract
Solvated electrons, and hydrated electrons in particular, are important species in condensed phase chemistry, physics, and biology. Many studies have examined the formation mechanism, reactivity, spectroscopy, and dynamics of electrons in aqueous solution and other solvents, leading to a fundamental understanding of the electron-solvent interaction. However, key aspects of solvated electrons remain controversial, and the interaction between hydrated electrons and water is of central interest. For example, although researchers generally accept that hydrated electrons, eaq-, occupy solvent cavities, another picture suggests that the electron resides in a diffuse orbital localized on a H3O radical. In addition, researchers have proposed two physically distinct models for the relaxation mechanism when the electron is excited. These models, formulated to interpret condensed phase experiments, have markedly different timescales for the internal conversion from the excited p state to the ground s state.Studies of negatively charged clusters, such as (H2O)n- and I-(H2O)n, offer a complementary perspective for studying aqueous electron solvation. In this Account, we use time-resolved photoelectron spectroscopy (TRPES), a femtosecond pump-probe technique in which mass-selected anions are electronically excited and then photodetached at a series of delay times, to focus on time-resolved dynamics in these and similar species. In (H2O)n-,TRPES gives evidence for ultrafast internal conversion in clusters up to n=100. Extrapolation of these results yields a p-state lifetime of 50 fs in the bulk limit. This is in good agreement with the nonadiabatic solvation model, one of the models proposed for relaxation of eaq-. Similarly, experiments on (MeOH)n- up to n=450 give an extrapolated p-state lifetime of 150fs. TRPES investigations of I-(H2O)n and I-(CH3CN)n probe a different aspect of electron solvation dynamics. In these experiments,an ultraviolet pump pulse excites the cluster analog of the charge-transfer-to-solvent (CTTS) band, ejecting an electron from the iodide into the solvent network. The probe pulse then monitors the solvent response to this excess electron,specifically its stabilization via solvent rearrangement. In I-(H2O)n, the iodide sits outside the solvent network, as does the excess electron initially formed by CTTS excitation. However, the iodide in I-(CH3CN)n is internally solvated, and both experimental and theoretical evidence indicate that electrons in (CH3CN)n- are internally solvated. Hence, these experiments reflect the complex dynamics that ensue when the electron is photo detached within a highly confined solvent cavity.
Collapse
Affiliation(s)
- Oli T. Ehrler
- Department of Chemistry, University of California, Berkeley, California 94720, and Chemical Sciences Division, Lawrence Berkeley National Laboratories, Berkeley, California 94720
| | - Daniel M. Neumark
- Department of Chemistry, University of California, Berkeley, California 94720, and Chemical Sciences Division, Lawrence Berkeley National Laboratories, Berkeley, California 94720
| |
Collapse
|
41
|
Griffin GB, Young RM, Ehrler OT, Neumark DM. Electronic relaxation dynamics in large anionic water clusters: (H[sub 2]O)[sub n]−] and (D[sub 2]O)[sub n]−] (n=25–200). J Chem Phys 2009; 131:194302. [DOI: 10.1063/1.3263419] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
|
42
|
|
43
|
Sommerfeld T, DeFusco A, Jordan KD. Model Potential Approaches for Describing the Interaction of Excess Electrons with Water Clusters: Incorporation of Long-Range Correlation Effects. J Phys Chem A 2008; 112:11021-35. [DOI: 10.1021/jp806077h] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- Thomas Sommerfeld
- Department of Chemistry and Physics, Southeastern Louisiana University, Hammond, Louisiana 70402, and Department of Chemistry and Center for Molecular and Materials Simulations, University of Pittsburgh, Pittsburgh, Pennsylvania 15260
| | - Albert DeFusco
- Department of Chemistry and Physics, Southeastern Louisiana University, Hammond, Louisiana 70402, and Department of Chemistry and Center for Molecular and Materials Simulations, University of Pittsburgh, Pittsburgh, Pennsylvania 15260
| | - Kenneth D. Jordan
- Department of Chemistry and Physics, Southeastern Louisiana University, Hammond, Louisiana 70402, and Department of Chemistry and Center for Molecular and Materials Simulations, University of Pittsburgh, Pittsburgh, Pennsylvania 15260
| |
Collapse
|
44
|
Jay-Gerin JP, Lin M, Katsumura Y, He H, Muroya Y, Meesungnoen J. Effect of water density on the absorption maximum of hydrated electrons in sub- and supercritical water up to 400 °C. J Chem Phys 2008; 129:114511. [DOI: 10.1063/1.2978955] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
|
45
|
|
46
|
Wang CR, Luo T, Lu QB. On the lifetimes and physical nature of incompletely relaxed electrons in liquid water. Phys Chem Chem Phys 2008; 10:4463-70. [DOI: 10.1039/b806287k] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
|
47
|
Bragg AE, Schwartz BJ. The ultrafast charge-transfer-to-solvent dynamics of iodide in tetrahydrofuran. 1. Exploring the roles of solvent and solute electronic structure in condensed-phase charge-transfer reactions. J Phys Chem B 2007; 112:483-94. [PMID: 18085770 DOI: 10.1021/jp076934s] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Although they represent the simplest possible charge-transfer reactions, the charge-transfer-to-solvent (CTTS) dynamics of atomic anions exhibit considerable complexity. For example, the CTTS dynamics of iodide in water are very different from those of sodide (Na-) in tetrahydrofuran (THF), leading to the question of the relative importance of the solvent and solute electronic structures in controlling charge-transfer dynamics. In this work, we address this issue by investigating the CTTS spectroscopy and dynamics of I- in THF, allowing us to make detailed comparisons to the previously studied I-/H2O and Na-/THF CTTS systems. Since THF is weakly polar, ion pairing with the counterion can have a substantial impact on the CTTS spectroscopy and dynamics of I- in this solvent. In this study, we have isolated "counterion-free" I- in THF by complexing the Na+ counterion with 18-crown-6 ether. Ultrafast pump-probe experiments reveal that THF-solvated electrons (e-THF) appear 380 +/- 60 fs following the CTTS excitation of "free" I- in THF. The absorption kinetics are identical at all probe wavelengths, indicating that the ejected electrons appear with no significant dynamic solvation but rather with their equilibrium absorption spectrum. After their initial appearance, ejected electrons do not exhibit any additional dynamics on time scales up to approximately 1 ns, indicating that geminate recombination of e-THF with its iodine atom partner does not occur. Competitive electron scavenging measurements demonstrate that the CTTS excited state of I- in THF is quite large and has contact with scavengers that are several nanometers away from the iodide ion. The ejection time and lack of electron solvation observed for I- in THF are similar to what is observed following CTTS excitation of Na- in THF. However, the relatively slow ejection time, the complete lack of dynamic solvation, and the large ejection distance/lack of recombination dynamics are in marked contrast to the CTTS dynamics observed for I- in water, in which fast electron ejection, substantial solvation, and appreciable recombination have been observed. These differences in dynamical behavior can be understood in terms of the presence of preexisting, electropositive cavities in liquid THF that are a natural part of its liquid structure; these cavities provide a mechanism for excited electrons to relocate to places in the liquid that can be nanometers away, explaining the large ejection distance and lack of recombination following the CTTS excitation of I- in THF. We argue that the lack of dynamic solvation observed following CTTS excitation of both I- and Na- in THF is a direct consequence of the fact that little additional relaxation is required once an excited electron nonadiabatically relaxes into one of the preexisting cavities. In contrast, liquid water contains no such cavities, and CTTS excitation of I- in water leads to local electron ejection that involves substantial solvent reorganization.
Collapse
Affiliation(s)
- Arthur E Bragg
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California 90095-1569, USA
| | | |
Collapse
|
48
|
Borgis D, Rossky PJ, Turi L. Nuclear quantum effects on the nonadiabatic decay mechanism of an excited hydrated electron. J Chem Phys 2007; 127:174508. [DOI: 10.1063/1.2780868] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
|
49
|
Kammrath A, Griffin GB, Verlet JRR, Young RM, Neumark DM. Time-resolved photoelectron imaging of large anionic methanol clusters: (Methanol)n−(n∼145–535). J Chem Phys 2007; 126:244306. [PMID: 17614548 DOI: 10.1063/1.2747618] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The dynamics of an excess electron in size-selected methanol clusters is studied via pump-probe spectroscopy with resolution of approximately 120 fs. Following excitation, the excess electron undergoes internal conversion back to the ground state with lifetimes of 260-175 fs in (CH3OH)n- (n=145-535) and 280-230 fs in (CD3OD)n- (n=210-390), decreasing with increasing cluster size. The clusters then undergo vibrational relaxation on the ground state on a time scale of 760+/-250 fs. The excited state lifetimes for (CH3OH)n- clusters extrapolate to a value of 157+/-25 fs in the limit of infinite cluster size.
Collapse
Affiliation(s)
- Aster Kammrath
- Department of Chemistry, University of California, Berkeley, California 94720, USA
| | | | | | | | | |
Collapse
|
50
|
Lindner J, Unterreiner AN, Vöhringer P. Femtosecond relaxation dynamics of solvated electrons in liquid ammonia. Chemphyschem 2007; 7:363-9. [PMID: 16463329 DOI: 10.1002/cphc.200500467] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The ultrafast relaxation dynamics of the well-known solvated electron in liquid ammonia solutions are investigated with femtosecond near-infrared pump-probe absorption spectroscopy. Immediately after photoexcitation, the dynamic absorption spectrum of the electron is substantially red-shifted with respect to its stationary spectrum. A subsequent dynamic blue shift of the pump-probe spectrum occurs on a timescale of 150 fs. The data are understood in terms of ground-state "cooling" and can be quantitatively simulated by an intuitive temperature-jump model employing a dynamically evolving Kubo line shape for the electronic resonance. A simple estimate implies that, on average, the electron in the liquid is coordinated to six nearest-neighbor ammonia molecules. An equivalent analysis of the data based on a bubble-formation/cavity-contraction mechanism is briefly outlined.
Collapse
Affiliation(s)
- Jörg Lindner
- Institut für Physikalische und Theoretische Chemie, Rheinische Friedrich-Wilhelms-Universität Bonn, Wegelerstrasse 12, 53115 Bonn (Germany)
| | | | | |
Collapse
|