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Workman KT, Usher AJ, Henson DW, White NJ, Gichuhi WK. Predicted Negative Ion Photoelectron Spectra of 1-, 2-, and 9-Cyanoanthracene Radical Anions and Computed Thermochemical Values of the Three Cyanoanthracene Isomers. J Phys Chem A 2023; 127:4063-4076. [PMID: 37116201 DOI: 10.1021/acs.jpca.3c01178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/30/2023]
Abstract
In this work, the negative ion photoelectron spectra of 1-, 2-, and 9-cyanoanthracene (anthracenecarbonitrile, ACN) radical anions, obtained via the calculation of Franck-Condon (FC) factors based on a harmonic oscillator model, are reported. The FC calculations utilize harmonic vibrational frequencies and normal mode vectors derived from density functional theory using the B3LYP/6-311++G (2d,2p) basis set. The removal of an electron from the doublet anion allows for the computation of the negative ion photoelectron spectra that represents the neutral ground singlet state (So) and the lowest triplet state (T1) in each of the three ACN molecules. The respective adiabatic electron affinity (EA) values for the So state in 1-, 2-, and 9-ACN isomers are calculated to be 1.353, 1.360, and 1.423 eV. The calculated EA of the 9-cyanoanthracene singlet isomer is in close agreement with the previously reported experimental value of 1.27 ± 0.1 eV. Calculations show that the T1 states in 1-, 2-, and 9-ACN are located 1.656, 1.663, and 1.599 eV above the So state. The calculated T1 negative ion spectra exhibit intense vibrational origins and weak FC activity beyond the origins, indicating little change in geometry following electron detachment from the doublet anionic state. Upon deprotonation, the EA values of the radical isomers increase by ∼400-700 meV, resulting in neutral deprotonated radicals with EAs between 1.740 and 2.220 eV. The calculated site-specific gas-phase acidity values of ACN isomers indicate that ACN molecules are more acidic than benzonitrile.
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Workman KT, Firth RA, Gichuhi WK. From Benzonitrile to Dicyanobenzenes: The Effect of an Additional CN Group on the Thermochemistry and Negative Ion Photoelectron Spectra of Dicyanobenzene Radical Anions. J Phys Chem A 2023; 127:181-194. [PMID: 36592400 DOI: 10.1021/acs.jpca.2c07655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The negative ion photoelectron spectra of 1,2-dicyanobenzene (o-DCNB), 1,3-dicyanobenzene (m-DCNB), and 1,4-dicyanobenzene (p-DCNB) radical anions (DCNB·-), acquired through the computation of Frack-Condon (FC) factors, are presented. The FC calculations utilize harmonic frequencies and normal mode vectors derived from density functional theory at the B3LYP/aug-cc-pVQZ basis set. All the totally symmetric vibrational modes are treated with Duschinsky rotations to yield neutral DCNBs in their singlet (So) and lowest triplet (T1) states, following an electron removal from the doublet anionic ground state. For the So state, the adiabatic electron affinities (EAs) for o-, m-, and p-DCNB are 1.179, 1.103, and 1.348 eV. The EAs for the lowest T1 state in o-, m-, and p-DCNB are 4.151, 4.185, and 4.208 eV, resulting in an So-T1 energy difference (ΔEST) of 2.973, 3.082, and 2.860 eV. A vibrational analysis reveals evidence of FC activity involving ring distortion, C-N bending, and ring C═C stretching vibrational progressions in both the So and T1 states. With the detection of cyanonaphthalene (C10H7CN) and cyanoindene (C9H7CN) in the interstellar medium (ISM), our results highlight the extent to which replacing a single hydrogen on an aromatic molecule with a cyano group, C≡N, can alter the vibrational structure of the molecule/radical anion. As such, dicyano-polyaromatic hydrocarbons may be reasonably robust in the ISM, making it appealing to search for them in future interstellar detection missions.
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Affiliation(s)
- Kie T Workman
- Department of Chemistry, Tennessee Tech University, 1 William L. Jones Dr., Cookeville, Tennessee38505, United States.,Department of Chemical Engineering, Tennessee Tech University, 1 William L. Jones Dr., Cookeville, Tennessee38505, United States
| | - Rebecca A Firth
- Department of Chemistry, Tennessee Tech University, 1 William L. Jones Dr., Cookeville, Tennessee38505, United States
| | - Wilson K Gichuhi
- Department of Chemistry, Tennessee Tech University, 1 William L. Jones Dr., Cookeville, Tennessee38505, United States
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Song H, Zhu Y, Pan M, Yang M. Dissociative photodetachment of H 3O 2-: a full-dimensional quantum dynamics study. Phys Chem Chem Phys 2021; 23:22298-22304. [PMID: 34590660 DOI: 10.1039/d1cp03495b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The transition state is a central concept of chemistry. Photoelectron-photofragment coincidence (PPC) spectroscopy has been proven as an attractive method to study the transition state dynamics. Within a state-of-the-art full-dimensional quantum mechanical model, the dissociative photodetachment dynamics of H3O2- is investigated on accurate anion and neutral potential energy surfaces. The calculated PPC spectrum of H3O2- agrees well with the experimental measurement. The dissociative product OH is exclusively populated on the ground vibrational state, implying the character of the spectator bond. In contrast, the product H2O is predominantly populated in the ground and fundamental states of the symmetric and antisymmetric stretching modes, which is caused by the strong coupling between the antisymmetric motion of the transferred H atom in the transient intermediate [H3O2]* and both stretching modes of the product H2O.
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Affiliation(s)
- Hongwei Song
- State Key Laboratory of 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.
| | - Yongfa Zhu
- State Key Laboratory of 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.
| | - Mengyi Pan
- State Key Laboratory of 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. .,College of Physical Science and Technology, Huazhong Normal University, Wuhan 430079, China
| | - Minghui Yang
- State Key Laboratory of 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
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Anstöter CS, Verlet JRR. Modeling the Photoelectron Angular Distributions of Molecular Anions: Roles of the Basis Set, Orbital Choice, and Geometry. J Phys Chem A 2021; 125:4888-4895. [PMID: 34042462 DOI: 10.1021/acs.jpca.1c03379] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A study investigating the effect of the basis set, orbital choice, and geometry on the modeling of photoelectron angular distributions (PADs) of molecular anions is presented. Experimental and modeled PADs for a number of molecular anions, including both closed- and open-shell systems, are considered. Guidelines are suggested for chemists who wish to design calculations to capture the correct chemical physics of the anisotropy of photodetachment, while balancing the computational cost associated with larger molecular anions.
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Affiliation(s)
- Cate S Anstöter
- Department of Chemistry, Durham University, Durham DH1 3LE, United Kingdom
| | - Jan R R Verlet
- Department of Chemistry, Durham University, Durham DH1 3LE, United Kingdom
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5
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Suits AG. Invited Review Article: Photofragment imaging. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2018; 89:111101. [PMID: 30501356 DOI: 10.1063/1.5045325] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Accepted: 10/25/2018] [Indexed: 06/09/2023]
Abstract
Photodissociation studies in molecular beams that employ position-sensitive particle detection to map product recoil velocities emerged thirty years ago and continue to evolve with new laser and detector technologies. These powerful methods allow application of tunable laser detection of single product quantum states, simultaneous measurement of velocity and angular momentum polarization, measurement of joint product state distributions for the detected and undetected products, coincident detection of multiple product channels, and application to radicals and ions as well as closed-shell molecules. These studies have permitted deep investigation of photochemical dynamics for a broad range of systems, revealed new reaction mechanisms, and addressed problems of practical importance in atmospheric, combustion, and interstellar chemistry. This review presents an historical overview, a detailed technical account of the range of methods employed, and selected experimental highlights illustrating the capabilities of the method.
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Affiliation(s)
- Arthur G Suits
- Department of Chemistry, University of Missouri, Columbia, Missouri 65211, USA
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Orms N, Krylov AI. Modeling Photoelectron Spectra of CuO, Cu2O, and CuO2 Anions with Equation-of-Motion Coupled-Cluster Methods: An Adventure in Fock Space. J Phys Chem A 2017; 122:3653-3664. [DOI: 10.1021/acs.jpca.7b10620] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Natalie Orms
- Department of Chemistry, University of Southern California, Los Angeles, California 90089-0482, United States
| | - Anna I. Krylov
- Department of Chemistry, University of Southern California, Los Angeles, California 90089-0482, United States
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7
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Dermer AR, Green ML, Mascaritolo KJ, Heaven MC. Photoelectron Velocity Map Imaging Spectroscopy of the Beryllium Sulfide Anion, BeS . J Phys Chem A 2017; 121:5645-5650. [PMID: 28691819 DOI: 10.1021/acs.jpca.7b04894] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Slow electron velocity map imaging (SEVI) spectroscopy was used to examine the BeS- anion to neutral ground-state transition, X 2Σ+ → X 1Σ+. Rotational constants, vibrational intervals, and the electron binding energy of BeS- were determined. Partially resolved rotational contours were seen due to the relatively small moment of inertia of beryllium sulfide. Upon analysis of the rotational contours, it was found that changes in the molecular rotational angular momentum, ΔN = -1, -2, -3, and -4, facilitated photodetachment at near-threshold photon energies. The electron affinity of BeS was found to be 2.3346(2) eV. SEVI spectra recorded using photon energies near the threshold for Δv = -1 processes exhibited features that were associated with a dipole-bound state (DBS) of BeS-. Autodetachment spectroscopy was used to probe this state, and rotationally resolved data were obtained for the DBS 2Σ+, v' = 0 - X 2Σ+, v″ = 0 transition. Analysis of this structure provided the rotational constants for BeS- X, v″ = 0, and the electron binding energy of the DBS. Electronic structure calculations, performed at the RCCSD(T) and MRCI levels of theory, gave predictions that were in good agreement with the experimental observations.
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Affiliation(s)
- Amanda R Dermer
- Department of Chemistry, Emory University , Atlanta, Georgia 30322, United States
| | - Mallory L Green
- Department of Chemistry, Emory University , Atlanta, Georgia 30322, United States
| | - Kyle J Mascaritolo
- Department of Chemistry, Emory University , Atlanta, Georgia 30322, United States
| | - Michael C Heaven
- Department of Chemistry, Emory University , Atlanta, Georgia 30322, United States
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8
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Krylov AI. The Quantum Chemistry of Open-Shell Species. REVIEWS IN COMPUTATIONAL CHEMISTRY 2017. [DOI: 10.1002/9781119356059.ch4] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Anna I. Krylov
- Department of Chemistry; University of Southern California; Los Angeles CA United States
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Affiliation(s)
| | - Catherine Walsh
- Leiden
Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden, The Netherlands
- School
of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, U.K
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10
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Gunina AO, Krylov AI. Probing Electronic Wave Functions of Sodium-Doped Clusters: Dyson Orbitals, Anisotropy Parameters, and Ionization Cross-Sections. J Phys Chem A 2016; 120:9841-9856. [DOI: 10.1021/acs.jpca.6b10098] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Anastasia O. Gunina
- Department of Chemistry, University of Southern California, Los Angeles, California 90089-0482, United States
| | - Anna I. Krylov
- Department of Chemistry, University of Southern California, Los Angeles, California 90089-0482, United States
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11
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Ma J, Guo H. Reactive and Nonreactive Feshbach Resonances Accessed by Photodetachment of FH2O(-). J Phys Chem Lett 2015; 6:4822-4826. [PMID: 26580571 DOI: 10.1021/acs.jpclett.5b02366] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The photodetachment of the FH2O(-) anion is investigated quantum mechanically on accurate full-dimensional potential energy surfaces of the two lowest-lying electronic states of FH2O. The calculated photoelectron spectrum possesses both broad and sharp features, corresponding to reactive and nonreactive Feshbach resonances. The former extend to both reactant and product channels over the transition state, while the latter are supported by a hydrogen bonded HO-HF well in the product channel. Many of the resonances are assignable with quantum numbers for the stretching and bending modes of the HO-HF complex as well as the H-F vibration. The implications of these resonances in the F + H2O ↔ HF + HO reaction are discussed.
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Affiliation(s)
- Jianyi Ma
- Institute of Atomic and Molecular Physics, Sichuan University , Chengdu, Sichuan 610065, China
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12
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Gozem S, Gunina AO, Ichino T, Osborn DL, Stanton JF, Krylov AI. Photoelectron wave function in photoionization: plane wave or Coulomb wave? J Phys Chem Lett 2015; 6:4532-4540. [PMID: 26509428 DOI: 10.1021/acs.jpclett.5b01891] [Citation(s) in RCA: 96] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The calculation of absolute total cross sections requires accurate wave functions of the photoelectron and of the initial and final states of the system. The essential information contained in the latter two can be condensed into a Dyson orbital. We employ correlated Dyson orbitals and test approximate treatments of the photoelectron wave function, that is, plane and Coulomb waves, by comparing computed and experimental photoionization and photodetachment spectra. We find that in anions, a plane wave treatment of the photoelectron provides a good description of photodetachment spectra. For photoionization of neutral atoms or molecules with one heavy atom, the photoelectron wave function must be treated as a Coulomb wave to account for the interaction of the photoelectron with the +1 charge of the ionized core. For larger molecules, the best agreement with experiment is often achieved by using a Coulomb wave with a partial (effective) charge smaller than unity. This likely derives from the fact that the effective charge at the centroid of the Dyson orbital, which serves as the origin of the spherical wave expansion, is smaller than the total charge of a polyatomic cation. The results suggest that accurate molecular photoionization cross sections can be computed with a modified central potential model that accounts for the nonspherical charge distribution of the core by adjusting the charge in the center of the expansion.
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Affiliation(s)
- Samer Gozem
- Department of Chemistry, University of Southern California , Los Angeles, California 90089-0482, United States
| | - Anastasia O Gunina
- Department of Chemistry, University of Southern California , Los Angeles, California 90089-0482, United States
| | - Takatoshi Ichino
- Institute for Theoretical Chemistry, Department of Chemistry, The University of Texas at Austin , Austin, Texas 78712, United States
| | - David L Osborn
- Combustion Research Facility, Sandia National Laboratories , Livermore, California 94551, United States
| | - John F Stanton
- Institute for Theoretical Chemistry, Department of Chemistry, The University of Texas at Austin , Austin, Texas 78712, United States
| | - Anna I Krylov
- Department of Chemistry, University of Southern California , Los Angeles, California 90089-0482, United States
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13
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Cheng X, Steele RP. Efficient anharmonic vibrational spectroscopy for large molecules using local-mode coordinates. J Chem Phys 2015; 141:104105. [PMID: 25217902 DOI: 10.1063/1.4894507] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
This article presents a general computational approach for efficient simulations of anharmonic vibrational spectra in chemical systems. An automated local-mode vibrational approach is presented, which borrows techniques from localized molecular orbitals in electronic structure theory. This approach generates spatially localized vibrational modes, in contrast to the delocalization exhibited by canonical normal modes. The method is rigorously tested across a series of chemical systems, ranging from small molecules to large water clusters and a protonated dipeptide. It is interfaced with exact, grid-based approaches, as well as vibrational self-consistent field methods. Most significantly, this new set of reference coordinates exhibits a well-behaved spatial decay of mode couplings, which allows for a systematic, a priori truncation of mode couplings and increased computational efficiency. Convergence can typically be reached by including modes within only about 4 Å. The local nature of this truncation suggests particular promise for the ab initio simulation of anharmonic vibrational motion in large systems, where connection to experimental spectra is currently most challenging.
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Affiliation(s)
- Xiaolu Cheng
- Department of Chemistry and Henry Eyring Center for Theoretical Chemistry, University of Utah, Salt Lake City, Utah 84112, USA
| | - Ryan P Steele
- Department of Chemistry and Henry Eyring Center for Theoretical Chemistry, University of Utah, Salt Lake City, Utah 84112, USA
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14
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Heaven MC, Barker BJ, Antonov IO. Spectroscopy and structure of the simplest actinide bonds. J Phys Chem A 2014; 118:10867-81. [PMID: 25243837 DOI: 10.1021/jp507283n] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Understanding the influence of electrons in partially filled f- and d-orbitals on bonding and reactivity is a key issue for actinide chemistry. This question can be investigated by using a combination of well-defined experimental measurements and theoretical calculations. Gas phase spectroscopic data are particularly valuable for the evaluation of theoretical models. Consequently, the primary objectives of our research have been to obtain gas phase spectra for small actinide molecules. To complement the experimental effort, we are investigating the potential for using relativistic ab initio calculations and semiempirical models to predict and interpret the electronic energy level patterns for f-element compounds. Multiple resonance spectroscopy and jet cooling techniques have been used to unravel the complex electronic spectra of Th and U compounds. Recent results for fluorides, sulfides, and nitrides are discussed.
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Affiliation(s)
- Michael C Heaven
- Department of Chemistry, Emory University , Atlanta, Georgia 30322, United States
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15
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Otto R, Ma J, Ray AW, Daluz JS, Li J, Guo H, Continetti RE. Imaging Dynamics on the F + H
2
O → HF + OH Potential Energy Surfaces from Wells to Barriers. Science 2014; 343:396-9. [DOI: 10.1126/science.1247424] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Rico Otto
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Jianyi Ma
- Institute of Atomic and Molecular Physics, Sichuan University, Chengdu, Sichuan 610065, China
- Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, NM 87131, USA
| | - Amelia W. Ray
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Jennifer S. Daluz
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Jun Li
- Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, NM 87131, USA
| | - Hua Guo
- Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, NM 87131, USA
| | - Robert E. Continetti
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
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Rudnev V, González Ureña A. Discharge source coupled to a deceleration unit for anion beam generation: application to H2- photodetachment. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2013; 84:124102. [PMID: 24387447 DOI: 10.1063/1.4847076] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
A cathode discharge source coupled to a deceleration unit for anion beam generation is described. The discharge source, made of stainless steel or duralumin electrodes and Macor insulators, is attached to the exit nozzle valve plate at one end, and to an Einzel lens to the other end. Subsequently, a cylindrical retardation unit is attached to the Einzel lens to decelerate the ions in order to optimize the laser beam interaction time required for spectroscopic investigations. The compact device is able to produce beam intensities of the order of 2 × 10(12) anions/cm(2) s and 20 μrad of angular divergence with kinetic energies ranging from 30 to 120 eV. Using distinct gas mixtures for the supersonic expansion together with a linear time-of-flight spectrometer, anions of great relevance in molecular astrophysics like, for example, H2(-), C3H(-), C2(-), C2H(-), HCN2(-), CO2(-), CO2H(-), C4(-), C4H(-), C5H4(-), C5H6(-), C7N(-), and C10N(-) were produced. Finally, in order to demonstrate the capability of the experimental technique the photodetachment cross-section of the metastable H2(-), predominantly in the (v = 0, J = 26) state, was measured following laser excitation at λexc = 565 nm obtaining a value of σph = 0.04 Ų [corrected]. To the best of our knowledge, it is the first time that this anion cross-section has been measured.
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Affiliation(s)
- V Rudnev
- Unidad de Láseres y Haces Moleculares, Instituto Pluridisciplinar, Universidad Complutense, Juan XXIII-1, Madrid 28040, Spain
| | - A González Ureña
- Unidad de Láseres y Haces Moleculares, Instituto Pluridisciplinar, Universidad Complutense, Juan XXIII-1, Madrid 28040, Spain
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Martin JP, Case AS, Gu Q, Darr JP, McCoy AB, Lineberger WC. Photofragmentation dynamics of ICN−(CO2)n clusters following visible excitation. J Chem Phys 2013; 139:064315. [DOI: 10.1063/1.4817664] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Holzmeier F, Lang M, Hader K, Hemberger P, Fischer I. H2CN+ and H2CNH+: New insight into the structure and dynamics from mass-selected threshold photoelectron spectra. J Chem Phys 2013; 138:214310. [DOI: 10.1063/1.4808050] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Affiliation(s)
- Fabian Holzmeier
- Institute of Physical and Theoretical Chemistry, University of Würzburg, Am Hubland, D-97074 Würzburg, Germany
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19
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Ma J, Li J, Guo H. Tunneling facilitated dissociation to H+CO2 in HOCO(-) photodetachment. PHYSICAL REVIEW LETTERS 2012; 109:063202. [PMID: 23006263 DOI: 10.1103/physrevlett.109.063202] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2012] [Indexed: 06/01/2023]
Abstract
Dissociative photodetachment of HOCO(-) is investigated with both five- and six-dimensional quantum models on an ab initio based accurate HOCO potential energy surface. Three experimentally observed channels, namely, HOCO, H+CO(2), and HO+CO, are identified in our theoretical simulations. Since the energy spectrum of the initial HOCO species prepared by photodetachment is mostly lower than both the HO+CO asymptote and dissociation barrier to H+CO(2), the production of H+CO(2) is almost exclusively via tunneling. However, the lowest-lying HOCO resonances are extremely long lived (~μs), which might elude experimental measurements through its decay products H+CO(2). Our results are in good agreement with almost all experimental data reported by the Continetti group using a new cryogenically cooled photoelectron-photofragment coincidence apparatus.
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Affiliation(s)
- Jianyi Ma
- Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico 87131, USA
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20
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Miller EM, Sheps L, Lu YJ, Case AS, McCoy AB, Lineberger WC. New view of the ICN A continuum using photoelectron spectroscopy of ICN-. J Chem Phys 2012; 136:044313. [PMID: 22299877 DOI: 10.1063/1.3679170] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Negative-ion photoelectron spectroscopy of ICN(-) (X̃ (2)Σ(+)) reveals transitions to the ground electronic state (X̃ (1)Σ(+)) of ICN as well as the first five excited states ((3)Π(2), (3)Π(1), Π(0(-) ) (3), Π(0(+) ) (3), and (1)Π(1)) that make up the ICN A continuum. By starting from the equilibrium geometry of the anion, photoelectron spectroscopy characterizes the electronic structure of ICN at an elongated I-C bond length of 2.65 Å. Because of this bond elongation, the lowest three excited states of ICN ((3)Π(2), (3)Π(1), and Π(0(-) ) (3)) are resolved for the first time in the photoelectron spectrum. In addition, the spectrum has a structured peak that arises from the frequently studied conical intersection between the Π(0(+) ) (3) and (1)Π(1) states. The assignment of the spectrum is aided by MR-SO-CISD calculations of the potential energy surfaces for the anion and neutral ICN electronic states, along with calculations of the vibrational levels supported by these states. Through thermochemical cycles involving spectrally narrow transitions to the excited states of ICN, we determine the electron affinity, EA(ICN), to be 1.34(5) (+0.04∕-0.02) eV and the anion dissociation energy, D(0)(X̃ (2)Σ(+) I-CN(-)), to be 0.83 (+0.04/-0.02) eV.
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Affiliation(s)
- Elisa M Miller
- JILA, Department of Chemistry and Biochemistry, University of Colorado at Boulder, Boulder, Colorado 80309, USA
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Fleming DG, Cottrell SP, McKenzie I, Macrae RM. New results for the formation of a muoniated radical in the Mu + Br2 system: a van der Waals complex or evidence for vibrational bonding in Br–Mu–Br? Phys Chem Chem Phys 2012; 14:10953-66. [DOI: 10.1039/c2cp41366c] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Garand E, Neumark DM. Study of RgS− and RgS (Rg = Ne, Ar, and Kr) via slow photoelectron velocity-map imaging spectroscopy and ab initio calculations. J Chem Phys 2011; 135:024302. [DOI: 10.1063/1.3605595] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
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24
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Sheps L, Miller EM, Horvath S, Thompson MA, Parson R, McCoy AB, Lineberger WC. Solvent-mediated charge redistribution in photodissociation of IBr(-) and IBr(-)(CO2). J Chem Phys 2011; 134:184311. [PMID: 21568510 DOI: 10.1063/1.3584203] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A combined experimental and theoretical investigation of photodissociation dynamics of IBr(-) and IBr(-)(CO(2)) on the B ((2)Σ(1/2)(+)) excited electronic state is presented. Time-resolved photoelectron spectroscopy reveals that in bare IBr(-) prompt dissociation forms exclusively I∗ + Br(-). Compared to earlier dissociation studies of IBr(-) excited to the A' ((2)Π(1∕2)) state, the signal rise is delayed by 200 ± 20 fs. In the case of IBr(-)(CO(2)), the product distribution shows the existence of a second major (∼40%) dissociation pathway, Br∗ + I(-). In contrast to the primary product channel, the signal rise associated with this pathway shows only a 50 ± 20 fs delay. The altered product branching ratio indicates that the presence of one solvent-like CO(2) molecule dramatically affects the electronic structure of the dissociating IBr(-). We explore the origins of this phenomenon with classical trajectories, quantum wave packet studies, and MR-SO-CISD calculations of the six lowest-energy electronic states of IBr(-) and 36 lowest-energy states of IBr. We find that the CO(2) molecule provides sufficient solvation energy to bring the initially excited state close in energy to a lower-lying state. The splitting between these states and the time at which the crossing takes place depend on the location of the solvating CO(2) molecule.
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Affiliation(s)
- Leonid Sheps
- JILA, Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309, USA
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25
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Lambrecht DS, Clark GNI, Head-Gordon T, Head-Gordon M. Simulated Photoelectron Spectra of the Cyanide-Water Anion via Quasiclassical Molecular Dynamics. J Phys Chem A 2011; 115:5928-35. [DOI: 10.1021/jp110334w] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Daniel S. Lambrecht
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Gary N. I. Clark
- Department of Bioengineering, University of California, Berkeley, California 94720, United States
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Teresa Head-Gordon
- Department of Bioengineering, University of California, Berkeley, California 94720, United States
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Martin Head-Gordon
- Department of Chemistry, University of California, Berkeley, California 94720, United States
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26
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McKay AR, Sanz ME, Mooney CRS, Minns RS, Gill EM, Fielding HH. Development of a new photoelectron spectroscopy instrument combining an electrospray ion source and photoelectron imaging. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2010; 81:123101. [PMID: 21198008 DOI: 10.1063/1.3505097] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
A new apparatus has been constructed that combines electrospray ionization with a quadrupole mass filter, hexapole ion trap, and velocity-map imaging. The purpose is to record photoelectron images of isolated chromophore anions. To demonstrate the capability of our instrument we have recorded the photodetachment spectra of isolated deprotonated phenol and indole anions. To our knowledge, this is the first time that the photodetachment energy of the deprotonated indole anion has been recorded.
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Affiliation(s)
- A R McKay
- Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdom
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27
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Zanuttini D, Douady J, Jacquet E, Giglio E, Gervais B. Structure and photoabsorption properties of cationic alkali dimers solvated in neon clusters. J Chem Phys 2010; 133:174503. [DOI: 10.1063/1.3490251] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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28
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Lenhardt JM, Ong MT, Choe R, Evenhuis CR, Martinez TJ, Craig SL. Trapping a Diradical Transition State by Mechanochemical Polymer Extension. Science 2010; 329:1057-60. [PMID: 20798315 DOI: 10.1126/science.1193412] [Citation(s) in RCA: 224] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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29
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Gomes ASP, Visscher L, Bolvin H, Saue T, Knecht S, Fleig T, Eliav E. The electronic structure of the triiodide ion from relativistic correlated calculations: A comparison of different methodologies. J Chem Phys 2010; 133:064305. [DOI: 10.1063/1.3474571] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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30
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Wu X, Qin ZB, Xie H, Wu XH, Cong R, Tang ZC. Collinear Velocity-map Photoelectron Imaging Spectrometer for Cluster Anions. CHINESE J CHEM PHYS 2010. [DOI: 10.1088/1674-0068/23/04/373-380] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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31
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Sheps L, Miller EM, Horvath S, Thompson MA, Parson R, McCoy AB, Lineberger WC. Solvent-Mediated Electron Hopping: Long-Range Charge Transfer in IBr
−
(CO
2
) Photodissociation. Science 2010; 328:220-4. [DOI: 10.1126/science.1184616] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Leonid Sheps
- JILA, Department of Chemistry and Biochemistry, University of Colorado at Boulder, Boulder, CO 80309, USA
| | - Elisa M. Miller
- JILA, Department of Chemistry and Biochemistry, University of Colorado at Boulder, Boulder, CO 80309, USA
| | - Samantha Horvath
- Department of Chemistry, The Ohio State University, Columbus, OH 43210, USA
| | - Matthew A. Thompson
- JILA, Department of Chemistry and Biochemistry, University of Colorado at Boulder, Boulder, CO 80309, USA
| | - Robert Parson
- JILA, Department of Chemistry and Biochemistry, University of Colorado at Boulder, Boulder, CO 80309, USA
| | - Anne B. McCoy
- Department of Chemistry, The Ohio State University, Columbus, OH 43210, USA
| | - W. Carl Lineberger
- JILA, Department of Chemistry and Biochemistry, University of Colorado at Boulder, Boulder, CO 80309, USA
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32
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Chichinin AI, Gericke KH, Kauczok S, Maul C. Imaging chemical reactions – 3D velocity mapping. INT REV PHYS CHEM 2009. [DOI: 10.1080/01442350903235045] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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33
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Oana CM, Krylov AI. Cross sections and photoelectron angular distributions in photodetachment from negative ions using equation-of-motion coupled-cluster Dyson orbitals. J Chem Phys 2009; 131:124114. [DOI: 10.1063/1.3231143] [Citation(s) in RCA: 156] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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34
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Douady J, Jacquet E, Giglio E, Zanuttini D, Gervais B. Non-adiabatic molecular dynamics of excited Na2+ solvated in Ar17 clusters. Chem Phys Lett 2009. [DOI: 10.1016/j.cplett.2009.06.032] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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35
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Samoylova E, Radloff W, Ritze HH, Schultz T. Observation of Proton Transfer in 2-Aminopyridine Dimer by Electron and Mass Spectroscopy. J Phys Chem A 2009; 113:8195-201. [DOI: 10.1021/jp903460b] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
| | | | | | - Thomas Schultz
- Max-Born-Institute, Max-Born-Str. 2A, 12489 Berlin, Germany
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36
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Sheps L, Miller EM, Lineberger WC. Photoelectron spectroscopy of small IBr[sup −](CO[sub 2])[sub n] (n=0–3) cluster anions. J Chem Phys 2009; 131:064304. [DOI: 10.1063/1.3200941] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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37
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Thompson MA, Martin JP, Darr JP, Lineberger WC, Parson R. A combined experimental/theoretical investigation of the near-infrared photodissociation of IBr−(CO2)n. J Chem Phys 2008; 129:224304. [DOI: 10.1063/1.3033746] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
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38
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Abstract
The experimental and theoretical study of molecular anions has undergone explosive growth over the past 40 years. Advances in techniques used to generate anions in appreciable numbers as well as new ion-storage, ion-optics, and laser spectroscopic tools have been key on the experimental front. Theoretical developments on the electronic structure and molecular dynamics fronts now allow one to achieve higher accuracy and to study electronically metastable states, thus bringing theory in close collaboration with experiment in this field. In this article, many of the experimental and theoretical challenges specific to studying molecular anions are discussed. Results from many research groups on several classes of molecular anions are overviewed, and both literature citations and active (in online html and pdf versions) links to numerous contributing scientists' Web sites are provided. Specific focus is made on the following families of anions: dipole-bound, zwitterion-bound, double-Rydberg, multiply charged, metastable, cluster-based, and biological anions. In discussing each kind of anion, emphasis is placed on the structural, energetic, spectroscopic, and chemical-reactivity characteristics that make these anions novel, interesting, and important.
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Affiliation(s)
- Jack Simons
- Chemistry Department, Henry Eyring Center for Theoretical Chemistry, UniVersity of Utah, Salt Lake City, Utah, USA
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39
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40
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Poisson L, Gloaguen E, Mestdagh JM, Soep B, Gonzalez A, Chergui M. Direct Observation of Microscopic Solvation at the Surface of Clusters by Ultrafast Photoelectron Imaging. J Phys Chem A 2008; 112:9200-10. [DOI: 10.1021/jp711259m] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Lionel Poisson
- Laboratoire Francis Perrin (CNRS-URA-2453), DSM/IRAMIS/Service des Photons, Atomes et Molécules, C.E.A. Saclay, F-91191 Gif-sur-Yvette Cedex, France, and Ecole Polytechnique Fédérale de Lausanne, Laboratoire de Spectroscopie Ultrarapide, ISIC, Faculté des Sciences de Base, BSP CH-1015 Lausanne-Dorigny, Switzerland
| | - Eric Gloaguen
- Laboratoire Francis Perrin (CNRS-URA-2453), DSM/IRAMIS/Service des Photons, Atomes et Molécules, C.E.A. Saclay, F-91191 Gif-sur-Yvette Cedex, France, and Ecole Polytechnique Fédérale de Lausanne, Laboratoire de Spectroscopie Ultrarapide, ISIC, Faculté des Sciences de Base, BSP CH-1015 Lausanne-Dorigny, Switzerland
| | - Jean-Michel Mestdagh
- Laboratoire Francis Perrin (CNRS-URA-2453), DSM/IRAMIS/Service des Photons, Atomes et Molécules, C.E.A. Saclay, F-91191 Gif-sur-Yvette Cedex, France, and Ecole Polytechnique Fédérale de Lausanne, Laboratoire de Spectroscopie Ultrarapide, ISIC, Faculté des Sciences de Base, BSP CH-1015 Lausanne-Dorigny, Switzerland
| | - Benoît Soep
- Laboratoire Francis Perrin (CNRS-URA-2453), DSM/IRAMIS/Service des Photons, Atomes et Molécules, C.E.A. Saclay, F-91191 Gif-sur-Yvette Cedex, France, and Ecole Polytechnique Fédérale de Lausanne, Laboratoire de Spectroscopie Ultrarapide, ISIC, Faculté des Sciences de Base, BSP CH-1015 Lausanne-Dorigny, Switzerland
| | - Alejandro Gonzalez
- Laboratoire Francis Perrin (CNRS-URA-2453), DSM/IRAMIS/Service des Photons, Atomes et Molécules, C.E.A. Saclay, F-91191 Gif-sur-Yvette Cedex, France, and Ecole Polytechnique Fédérale de Lausanne, Laboratoire de Spectroscopie Ultrarapide, ISIC, Faculté des Sciences de Base, BSP CH-1015 Lausanne-Dorigny, Switzerland
| | - Majed Chergui
- Laboratoire Francis Perrin (CNRS-URA-2453), DSM/IRAMIS/Service des Photons, Atomes et Molécules, C.E.A. Saclay, F-91191 Gif-sur-Yvette Cedex, France, and Ecole Polytechnique Fédérale de Lausanne, Laboratoire de Spectroscopie Ultrarapide, ISIC, Faculté des Sciences de Base, BSP CH-1015 Lausanne-Dorigny, Switzerland
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41
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Lee IR, Lee W, Zewail AH. Dynamics of electrons in ammonia cages: the discovery system of solvation. Chemphyschem 2008; 9:83-8. [PMID: 18038379 DOI: 10.1002/cphc.200700562] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Two centuries ago solvated electrons were discovered in liquid ammonia and a century later the concept of the solvent cage was introduced. Here, we report a real time study of the dynamics of size-selected clusters, n=20 to 60, of electrons in ammonia, and, for comparison, that of electrons in water cages. Unlike the water case, the observed dynamics for ammonia indicates the formation, through a 100 fs temperature jump, of a solvent collective motion in a 500 fs relaxation process. The agreement of the experimental results-obtained for a well-defined n, gated electron kinetic energy, and time delay-with molecular dynamics theory suggests the critical and different role of the kinetic energy and the librational motions involved in solvation.
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Affiliation(s)
- I-Ren Lee
- Physical Biology Center for Ultrafast Science and Technology, Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena, CA 91125, USA
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42
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Grinev TA, Buchachenko AA. Photoelectron spectroscopy of the Cl−…H2∕D2 anions: A model beyond the rotationless and Franck–Condon approximations. J Chem Phys 2008; 128:154317. [DOI: 10.1063/1.2894306] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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43
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Garand E, Zhou J, Manolopoulos DE, Alexander MH, Neumark DM. Nonadiabatic Interactions in the Cl + H
2
Reaction Probed by ClH
2
-
and ClD
2
-
Photoelectron Imaging. Science 2008; 319:72-5. [DOI: 10.1126/science.1150602] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Etienne Garand
- Department of Chemistry, University of California, Berkeley, CA 94720, USA
- Physical and Theoretical Chemistry Laboratory, Oxford University, South Parks Road, Oxford OX1 3QZ, UK
- Department of Chemistry and Biochemistry and Institute for Physical Science and Technology, University of Maryland, College Park, MD 20742, USA
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Jia Zhou
- Department of Chemistry, University of California, Berkeley, CA 94720, USA
- Physical and Theoretical Chemistry Laboratory, Oxford University, South Parks Road, Oxford OX1 3QZ, UK
- Department of Chemistry and Biochemistry and Institute for Physical Science and Technology, University of Maryland, College Park, MD 20742, USA
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - David E. Manolopoulos
- Department of Chemistry, University of California, Berkeley, CA 94720, USA
- Physical and Theoretical Chemistry Laboratory, Oxford University, South Parks Road, Oxford OX1 3QZ, UK
- Department of Chemistry and Biochemistry and Institute for Physical Science and Technology, University of Maryland, College Park, MD 20742, USA
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Millard H. Alexander
- Department of Chemistry, University of California, Berkeley, CA 94720, USA
- Physical and Theoretical Chemistry Laboratory, Oxford University, South Parks Road, Oxford OX1 3QZ, UK
- Department of Chemistry and Biochemistry and Institute for Physical Science and Technology, University of Maryland, College Park, MD 20742, USA
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Daniel M. Neumark
- Department of Chemistry, University of California, Berkeley, CA 94720, USA
- Physical and Theoretical Chemistry Laboratory, Oxford University, South Parks Road, Oxford OX1 3QZ, UK
- Department of Chemistry and Biochemistry and Institute for Physical Science and Technology, University of Maryland, College Park, MD 20742, USA
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
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44
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Abstract
A hydrated electron in water at different densities and temperatures is studied via a set of density functional based molecular dynamics simulations, showing that a localization of an excess electron is still present even at very low densities. Space variations of the molecular dipole moments are analyzed, proposing a simple algorithm to identify the region of localization of the wavefunction relative to the solvated electron in terms of orientation of the H2O molecular dipole moments. Finally, the effects of the self-interaction corrections on the optical absorption spectra are analyzed and compared with both available experimental data and path integral molecular dynamics calculations, showing that a weighted subtraction of the self-interaction yields a systematic improvement in the position of the absorption peak.
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Affiliation(s)
- Mauro Boero
- Center for Computational Sciences, University of Tsukuba, Tennodai 1-1-1, Tsukuba, Ibaraki 305-8577, Japan.
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45
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Lu Z, Continetti RE. Alignment of a molecular anion via a shape resonance in near-threshold photodetachment. PHYSICAL REVIEW LETTERS 2007; 99:113005. [PMID: 17930436 DOI: 10.1103/physrevlett.99.113005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2007] [Indexed: 05/25/2023]
Abstract
One-color-two-photon photodetachment of HOCO- at E hnu=1.60 eV accompanied by a measurement of the photoelectron angular distribution (PAD) is used to illustrate a novel approach to the alignment of a molecular anion. A quantitative analysis of the PAD reveals this alignment process is associated with a temporary anion formed by a p-wave shape resonance and the PAD in the two-photon signal is a result of interfering s- and d-partial waves within the atomic approximation. The extracted intensity and phase shift of the partial waves are consistent with the Wigner threshold law for photodetachment.
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Affiliation(s)
- Zhou Lu
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0340, USA
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46
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Sciaini G, Fernández-Prini R, Estrin DA, Marceca E. Short-range and long-range solvent effects on charge-transfer-to-solvent transitions of I- and K+I- contact ion pair dissolved in supercritical ammonia. J Chem Phys 2007; 126:174504. [PMID: 17492871 DOI: 10.1063/1.2723723] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Vertical excitation and electron detachment energies associated with the optical absorption of iodide ions dissolved in supercritical ammonia at 420 K have been calculated in two limiting scenarios: as a solvated free I- ion and forming a K+I- contact ion pair (CIP). The evolution of the transition energies as a result of the gradual building up of the solvation structure was studied for each absorbing species as the solvent's density increased, i.e., changing the NH3 supercritical thermodynamic state. In both cases, if the solvent density is sufficiently high, photon absorption produces a spatially extended electron charge beyond the volume occupied by the solvated solute core; this excited state resembles a typical charge-transfer-to-solvent (CTTS) state. A combination of classical molecular dynamics simulations followed by quantum mechanical calculations for the ground, first-excited, and electron-detached electronic states have been carried out for the system consisting of one donor species (free I- ion or K+I- CIP) surrounded by ammonia molecules. Vertical excitation and electron detachment energies were obtained by averaging 100 randomly chosen microconfigurations along the molecular dynamics trajectory computed for each thermodynamic condition (fluid density). Short- and long-range contributions of the solvent-donor interaction upon the CTTS states of I- and K+I- were identified by performing additional electronic structure calculations where only the solvent interaction due to the first neighbor molecules was taken into account. These computations, together with previous experimental evidence that we collected for the system, have been used to analyze the solvent effects on the CTTS transition. In this paper we have established the following: (i) the CTTS electron of free I- ion or K+I- CIP presents similar features, and it gradually localizes in close proximity of the iodine parent atom when the ammonia density is increased; (ii) for the free I- ion, the short-range solvent interaction contributes to the stabilization of the ground state more than it does for the CTTS excited state, which is evidenced experimentally as a blueshift in the maximum absorption of the CTTS transition when the density is increased; (iii) this effect is less noticeable for the K+I- ion pair, because in this case a tight solvation structure, formed by four NH3 molecules wedged between the ions, appears at very low density and is very little affected by changes in the density; (iv) the long-range contribution to the solvent stabilization can be neglected for the K+I- CIP, since the main features of its electronic transition can be explained on the basis of the vicinity of the cation; (v) however, the long-range solvent field contribution is essential for the free I- ion to become an efficient CTTS donor upon photoexcitation, and this establishes a difference in the CTTS behavior of I- in bulk and in clusters.
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Affiliation(s)
- G Sciaini
- INQUIMAE-DQIAQF, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellón II, C1428EHA Buenos Aires, Argentina
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47
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Barbera J, Horvath S, Dribinski V, McCoy AB, Lineberger WC. Femtosecond dynamics of Cu(CD3OD). J Chem Phys 2007; 126:084307. [PMID: 17343448 DOI: 10.1063/1.2464103] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
We report the femtosecond nuclear dynamics of Cu(CD3OD) van der Waals clusters, investigated using photodetachment-photoionization spectroscopy. Photodetachment of an electron from Cu-(CD3OD) with a 150 fs, 398 nm laser pulse produces a vibrationally excited neutral complex that undergoes ligand reorientation and dissociation. The dynamics of Cu(CD3OD) on the neutral surface is interrogated by delayed femtosecond resonant two-photon ionization. Analysis of the resulting time-dependent signals indicates that the nascent Cu(CD3OD) complex dissociates on two distinct time scales of 3 and 30 ps. To understand the origins of the observed time scales, complimentary studies were performed. These included measurement of the photoelectron spectrum of Cu-(CD3OD) as well as a series of calculations of the structure and the electronic and vibrational energies of the anion and neutral complexes. Based on the comparisons of the experimental and calculated results for Cu(CD3OD) with those obtained from earlier studies of Cu(H2O), we conclude that the 3 ps time scale reflects the energy transfer from the rotation of CD3OD in the complex to the dissociation coordinate, while the 30 ps time scale reflects the energy transfer from the excited methyl torsion states to the dissociation coordinate.
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Affiliation(s)
- Jack Barbera
- JILA, and Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309, USA
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48
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Wild DA, Lenzer T. Structures, energetics, and infrared spectra of the Cl––(H2S)n and Br––(H2S)n anion clusters from ab initio calculations. Phys Chem Chem Phys 2007; 9:5776-84. [DOI: 10.1039/b710111b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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49
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Dribinski V, Barbera J, Martin JP, Svendsen A, Thompson MA, Parson R, Lineberger WC. Time-resolved study of solvent-induced recombination in photodissociated IBr−(CO2)n clusters. J Chem Phys 2006; 125:133405. [PMID: 17029479 DOI: 10.1063/1.2217741] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
We report the time-resolved recombination of photodissociated IBr-(CO2)n (n = 5-10) clusters following excitation to the dissociative IBr-A' 2Pi12 state of the chromophore via a 180 fs, 795 nm laser pulse. Dissociation from the A' state of the bare anion results in I- and Br products. Upon solvation with CO2, the IBr- chromophore regains near-IR absorption only after recombination and vibrational relaxation on the ground electronic state. The recombination time was determined by using a delayed femtosecond probe laser, at the same wavelength as the pump, and detecting ionic photoproducts of the recombined IBr- cluster ions. In sharp contrast to previous studies involving solvated I2-, the observed recombination times for IBr-(CO2)n increase dramatically with increasing cluster size, from 12 ps for n = 5 to 900 ps for n = 8,10. The nanosecond recombination times are especially surprising in that the overall recombination probability for these cluster ions is unity. Over the range of 5-10 solvent molecules, calculations show that the solvent is very asymmetrically distributed, localized around the Br end of the IBr- chromophore. It is proposed that this asymmetric solvation delays the recombination of the dissociating IBr-, in part through a solvent-induced well in the A' state that (for n = 8,10) traps the evolving complex. Extensive electronic structure calculations and nonadiabatic molecular dynamics simulations provide a framework to understand this unexpected behavior.
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