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Kang DH, Cho KH, Kim J, Eun HJ, Rhee YM, Kim SK. Electron-Binding Dynamics of the Dipole-Bound State: Correlation Effect on the Autodetachment Dynamics. J Am Chem Soc 2023; 145:25824-25833. [PMID: 37972034 DOI: 10.1021/jacs.3c10099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2023]
Abstract
The nature of the electron-binding forces in the dipole-bound states (DBS) of anions is interrogated through experimental and theoretical means by investigating the autodetachment dynamics from DBS Feshbach resonances of ortho-, meta-, and para-bromophenoxide (BrPhO-). Though the charge-dipole electrostatic potential has been widely regarded to be mainly responsible for the electron binding in DBS, the effect of nonclassical electron correlation has been conceived to be quite significant in terms of its static and/or dynamic contributions toward the binding of the excess electron to the neutral core. State-specific real-time autodetachment dynamics observed by picosecond time-resolved photoelectron velocity-map imaging spectroscopy reveal that the autodetachment processes from the DBS Feshbach resonances of BrPhO- anions cannot indeed be rationalized by the conventional charge-dipole potential. Specifically, the autodetachment lifetime is drastically lengthened depending on differently positioned Br-substitution, and this rate change cannot be explained within the framework of Fermi's golden rule based on the charge-dipole assumption. High-level ab initio quantum chemical calculations with EOM-EA-CCSD, which intrinsically takes into account electron correlations, generate more reasonable predictions on the binding energies than density functional theory (DFT) calculations, and semiclassical quantum dynamics simulations based on the EOM-EA-CCSD data excellently predict the trend in the autodetachment rates. These findings illustrate that static and dynamic properties of the excess electron in the DBS are strongly influenced by correlation interactions among electrons in the nonvalence orbital of the dipole-bound electron and highly polarizable valence orbitals of the bromine atom, which, in turn, dictate the interesting chemical fate of exotic anion species.
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Affiliation(s)
- Do Hyung Kang
- Department of Chemistry, KAIST, Daejeon 34141, Republic of Korea
| | - Kwang Hyun Cho
- Department of Chemistry, KAIST, Daejeon 34141, Republic of Korea
| | - Jinwoo Kim
- Department of Chemistry, KAIST, Daejeon 34141, Republic of Korea
| | - Han Jun Eun
- Department of Chemistry, KAIST, Daejeon 34141, Republic of Korea
| | - Young Min Rhee
- Department of Chemistry, KAIST, Daejeon 34141, Republic of Korea
| | - Sang Kyu Kim
- Department of Chemistry, KAIST, Daejeon 34141, Republic of Korea
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2
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Zhang YR, Yuan DF, Qian CH, Zhu GZ, Wang LS. Role of Polarization Interactions in the Formation of Dipole-Bound States. J Am Chem Soc 2023. [PMID: 37368495 DOI: 10.1021/jacs.3c04740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/29/2023]
Abstract
Even though there is a critical dipole moment required to support a dipole-bound state (DBS), how molecular polarizability may influence the formation of DBSs is not well understood. Pyrrolide, indolide, and carbazolide provide an ideal set of anions to systematically examine the role of polarization interactions in the formation of DBSs. Here, we report an investigation of carbazolide using cryogenic photodetachment spectroscopy and high-resolution photoelectron spectroscopy (PES). A polarization-assisted DBS is observed at 20 cm-1 below the detachment threshold for carbazolide, even though the carbazolyl neutral core has a dipole moment (2.2 D) smaller than the empirical critical value (2.5 D) to support a dipole-bound state. Photodetachment spectroscopy reveals nine vibrational Feshbach resonances of the DBS, as well as three intense and broad shape resonances. The electron affinity of carbazolyl is measured accurately to be 2.5653 ± 0.0004 eV (20,691 ± 3 cm-1). The combination of photodetachment spectroscopy and resonant PES allows fundamental frequencies for 14 vibrational modes of carbazolyl to be measured. The three shape resonances are due to above-threshold excitation to the three low-lying electronic states (S1-S3) of carbazolide. Resonant PES of the shape resonances is dominated by autodetachment processes. Ultrafast relaxation from the S2 and S3 states to S1 is observed, resulting in constant kinetic energy features in the resonant PES. The current study provides decisive information about the role that polarization plays in the formation of DBSs, as well as rich spectroscopic information about the carbazolide anion and the carbazolyl radical.
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Affiliation(s)
- Yue-Rou Zhang
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, United States
| | - Dao-Fu Yuan
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, United States
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230026, China
| | - Chen-Hui Qian
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, United States
| | - Guo-Zhu Zhu
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, United States
| | - Lai-Sheng Wang
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, United States
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3
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Kang DH, Kim J, Eun HJ, Kim SK. Experimental Observation of the Resonant Doorways to Anion Chemistry: Dynamic Role of Dipole-Bound Feshbach Resonances in Dissociative Electron Attachment. J Am Chem Soc 2022; 144:16077-16085. [PMID: 35973092 DOI: 10.1021/jacs.2c06334] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Anion chemical dynamics of autodetachment and fragmentation mediated by the dipole-bound state (DBS) have been thoroughly investigated in a state-specific way by employing the picosecond time-resolved or the nanosecond frequency-resolved spectroscopy combined with the cryogenically cooled ion trap and velocity-map imaging techniques. For the ortho-, meta-, or para-iodophenoxide anion (o-, m-, or p-IPhO-), the C-I bond rupture occurs via the nonadiabatic transition from the DBS to the nearby valence-bound states (VBS) of the anion where the vibronic coupling into the S1 (πσ*) state (repulsive along the C-I bond extension coordinate) should be largely responsible. Dynamic details are governed by the isomer-specific nature of the potential energy surfaces in the vicinity of the DBS-VBS curve crossings, as manifested in the huge different chemical reactivity of o-, m-, or p-IPhO-. It is confirmed here that the C-I bond dissociation is mediated by DBS resonances, providing the foremost evidence that the metastable DBS plays the critical role as the doorway into the anion chemistry especially of the dissociative electron attachment (DEA). The fragmentation channel is dominant when it is mediated by the DBS resonances located below the electron-affinity (EA) threshold, whereas it is kinetically adjusted by the competitive autodetachment when the DBS resonances above EA convey the electron to the valence orbitals. The product yield of the C-I bond cleavage is strongly mode-dependent as the rate of the concomitant autodetachment is much influenced by the characteristics of the individual vibrational modes, paving a new way of the reaction control of the anion chemistry.
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Affiliation(s)
- Do Hyung Kang
- Department of Chemistry, KAIST, Daejeon 34141, Republic of Korea
| | - Jinwoo Kim
- Department of Chemistry, KAIST, Daejeon 34141, Republic of Korea
| | - Han Jun Eun
- Department of Chemistry, KAIST, Daejeon 34141, Republic of Korea
| | - Sang Kyu Kim
- Department of Chemistry, KAIST, Daejeon 34141, Republic of Korea
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Bull JN, Anstöter CS, Stockett MH, Clarke CJ, Gibbard JA, Bieske EJ, Verlet JRR. Nonadiabatic Dynamics between Valence, Nonvalence, and Continuum Electronic States in a Heteropolycyclic Aromatic Hydrocarbon. J Phys Chem Lett 2021; 12:11811-11816. [PMID: 34870432 DOI: 10.1021/acs.jpclett.1c03532] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Internal conversion between valence-localized and dipole-bound states is thought to be a ubiquitous process in polar molecular anions, yet there is limited direct evidence. Here, photodetachment action spectroscopy and time-resolved photoelectron imaging with a heteropolycyclic aromatic hydrocarbon (hetero-PAH) anion, deprotonated 1-pyrenol, is used to demonstrate a subpicosecond (τ1 = 160 ± 20 fs) valence to dipole-bound state internal conversion following excitation of the origin transition of the first valence-localized excited state. The internal conversion dynamics are evident in the photoelectron spectra and in the photoelectron angular distributions (β2 values) as the electronic character of the excited state population changes from valence to nonvalence. The dipole-bound state subsequently decays through mode-specific vibrational autodetachment with a lifetime τ2 = 11 ± 2 ps. These internal conversion and autodetachment dynamics are likely common in molecular anions but difficult to fingerprint due to the transient existence of the dipole-bound state. Potential implications of the present excited state dynamics for interstellar hetero-PAH anion formation are discussed.
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Affiliation(s)
- James N Bull
- School of Chemistry, Norwich Research Park, University of East Anglia, Norwich NR4 7TJ, United Kingdom
| | - Cate S Anstöter
- Department of Chemistry, Temple University, 1901 N 13th Street, Philadelphia, Pennsylvania 19122, United States
| | - Mark H Stockett
- Department of Physics, Stockholm University, Stockholm SE-106 91, Sweden
| | - Connor J Clarke
- Department of Chemistry, Durham University, Durham DH1 3LE, United Kingdom
| | - Jemma A Gibbard
- Department of Chemistry, Durham University, Durham DH1 3LE, United Kingdom
| | - Evan J Bieske
- School of Chemistry, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Jan R R Verlet
- Department of Chemistry, Durham University, Durham DH1 3LE, United Kingdom
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Laws BA, Levey ZD, Schmidt TW, Gibson ST. Velocity Map Imaging Spectroscopy of the Dipole-Bound State of CH 2CN -: Implications for the Diffuse Interstellar Bands. J Am Chem Soc 2021; 143:18684-18692. [PMID: 34726415 DOI: 10.1021/jacs.1c08762] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Weakly bound anionic systems present a new domain for negative ion spectroscopy. Here we report on a multifaceted study of the CH2CN- dipole-bound state, employing high-resolution photoelectron spectroscopy from 130 different wavelengths, velocity-map imaging at threshold, and laser scanning photodetachment experiments. This uncovers a wide variety of different vibrational and rotational autodetaching resonances. By examination of both sides of the problem, absorption from the anion to the dipole-bound state and vibrational/rotational autodetachment to the neutral, a complete model of the dipole-bound chemistry is formed. Precise values for the electron affinity EA = 12468.9(1) cm-1, dipole binding energy DBE = 40.2(3) cm-1, and anion inversion splitting ω5 = 115.9(2) cm-1 are obtained. This model is then employed to study possible astronomical implications, revealing good agreement between the K = 1 ← 0 CH2CN- dipole transition and the λ8040 diffuse interstellar band.
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Affiliation(s)
- Benjamin A Laws
- School of Chemistry, University of New South Wales, Sydney, NSW 2052, Australia.,Research School of Physics, The Australian National University, Canberra, ACT 2601, Australia
| | - Zachariah D Levey
- School of Chemistry, University of New South Wales, Sydney, NSW 2052, Australia
| | - Timothy W Schmidt
- School of Chemistry, University of New South Wales, Sydney, NSW 2052, Australia
| | - Stephen T Gibson
- Research School of Physics, The Australian National University, Canberra, ACT 2601, Australia
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Lietard A, Verlet JRR, Slimak S, Jordan KD. Temporary Anion Resonances of Pyrene: A 2D Photoelectron Imaging and Computational Study. J Phys Chem A 2021; 125:7004-7013. [PMID: 34369146 DOI: 10.1021/acs.jpca.1c05586] [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
The low-energy electron-scattering resonances of pyrene were characterized using experimental and computational methods. Experimentally, a two-dimensional photoelectron imaging of the pyrene anion was used to probe the dynamics of resonances over the first 4 eV of the continuum. Computationally, the energies and character of the anion states were determined using equation-of-motion coupled cluster calculations, while taking specific care to avoid the collapse onto discretized continuum levels, and an application of the pairing theorem. Our results are in good agreement with the predictions of electron-scattering calculations that include an offset and with the pyrene anion absorption spectrum in a glass matrix. Taken together, we offer an assignment of the first five electronic resonances of pyrene. Some of the population in the lowest-energy 2B1u resonance was observed to decay to the ground electronic state of the anion, while all other resonances decay by a direct autodetachment. The astronomical relevance of a ground-state electron capture proceeding via a low-energy resonance in pyrene is discussed.
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Affiliation(s)
- Aude Lietard
- Department of Chemistry, Durham University, Durham DH1 3LE, United Kingdom
| | - Jan R R Verlet
- Department of Chemistry, Durham University, Durham DH1 3LE, United Kingdom
| | - Stephen Slimak
- Department of Chemistry, University of Pittsburgh, Pittsburgh 15260, Pennsylvania, United States
| | - Kenneth D Jordan
- Department of Chemistry, University of Pittsburgh, Pittsburgh 15260, Pennsylvania, United States
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Sagan CR, Garand E. Anion Resonances and Photoelectron Spectroscopy of the Tetracenyl Anion. J Phys Chem A 2021; 125:7014-7022. [PMID: 34370462 DOI: 10.1021/acs.jpca.1c05938] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The photoelectron spectroscopy of the tetracenyl anion using slow electron velocity-map imaging (SEVI) of cryogenically cooled ions is presented. The total photodetachment yield as a function of photon energy is used to reveal a rich manifold of anion excited states above the detachment threshold. The lowest energy anionic resonance has a sufficiently long lifetime to yield a vibrationally resolved absorption spectrum that can be directly compared with theoretical predictions. Excitation of this state mostly results in electron detachment via thermionic emission. The total photodetachment yield spectrum is used to select photon wavelengths that minimize the indirect detachment signal to allow acquisition of vibrationally resolved photoelectron spectra that can inform on the neutral tetracenyl radical. Assignment of spectral features corresponding to the ground and first excited state of the neutral 12-tetracenyl isomer is made with the aid of Franck-Condon simulations. This yields adiabatic electron affinity and term energies that differ significantly from the previously reported values. Weak features corresponding to the ground state of the minor 2-teracenyl and 1-tetracenyl isomers are also identified, which allows for the experimental determination of their electron affinities for the first time.
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Affiliation(s)
- Cole R Sagan
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Etienne Garand
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
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