1
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Van Dorn L, Sanov A. A density-matrix adaptation of the Hückel method to weak covalent networks. Phys Chem Chem Phys 2024; 26:5879-5894. [PMID: 38314532 DOI: 10.1039/d3cp05697j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2024]
Abstract
The coupled-monomers model is built as an adaptation of the Hückel MO theory based on a self-consistent density-matrix formalism. The distinguishing feature of the model is its reliance on variable bond and Coulomb integrals that depend on the elements of the density matrix: the bond orders and partial charges, respectively. Here the model is used to describe electron reactivity in weak covalent networks Xn±, where X is a closed-shell monomer. Viewing the electron as the simplest chemical reagent, the model provides insight into charge sharing and localisation in chains of such identical monomers. Data-driven modelling improves the results by training the model to experimental or ab initio data. Among key outcomes is the prediction that the charge in Xn± clusters tends to localise on a few (2-3) monomers. This is confirmed by the properties of several known cluster families, including Hen+, Arn+, (glyoxal)n-, and (biacetyl)n-. Since this prediction is obtained in a purely coherent covalent regime without any thermal excitation, it implies that charge localisation does not require non-covalent perturbations (such as solvation), decoherence, or free-energy effects. Instead, charge localisation is an intrinsic feature of weak covalent networks arising from their geometry relaxation and is ultimately attributed to the correlation between covalent bond orders and equilibrium bond integrals.
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Affiliation(s)
- Laura Van Dorn
- Department of Chemistry and Biochemistry, The University of Arizona, Tucson, Arizona 85721, USA.
| | - Andrei Sanov
- Department of Chemistry and Biochemistry, The University of Arizona, Tucson, Arizona 85721, USA.
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2
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Fan M, Xie J, Wang E, Tian SX. Evaporative cooling and reaction of carbon dioxide clusters by low-energy electron attachment. J Chem Phys 2024; 160:044301. [PMID: 38251801 DOI: 10.1063/5.0179993] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Accepted: 01/01/2024] [Indexed: 01/23/2024] Open
Abstract
Anionic carbonate CO3- has been found in interstellar space and the Martian atmosphere, but its production mechanism is in debate so far. To mimic the irradiation-induced reactions on icy micrograins in the Martian atmosphere and the icy shell of interstellar dust, here we report a laboratory investigation on the dissociative electron attachments to the molecular clusters of CO2. We find that anionic species (CO2)n-1O- and (CO2)n- (n = 2, 3, 4) are produced in the concerted reaction and further stabilized by the evaporative cooling after the electron attachment. We further propose a dynamics model to elucidate their competitive productions: the (CO2)n- yields survive substantially in the molecular evaporative cooling at the lower electron attachment energy, while the reactions leading to (CO2)n-1O- are favored at the higher attachment energy. This work provides new insights into physicochemical processes in CO2-rich atmospheres and interstellar space.
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Affiliation(s)
- Mengyuan Fan
- Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, China
| | - Jingchen Xie
- Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, China
| | - Enliang Wang
- Department of Modern Physics, University of Science and Technology of China, Hefei 230026, China
- Hefei National Research Center for Physical Sciences at Microscale, University of Science and Technology of China, Hefei 230026, China
| | - Shan Xi Tian
- Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, China
- Hefei National Research Center for Physical Sciences at Microscale, University of Science and Technology of China, Hefei 230026, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei 230088, China
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3
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Jarrold CC. Probing Anion-Molecule Complexes of Atmospheric Relevance Using Anion Photoelectron Detachment Spectroscopy. ACS PHYSICAL CHEMISTRY AU 2023; 3:17-29. [PMID: 36718261 PMCID: PMC9881448 DOI: 10.1021/acsphyschemau.2c00060] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Revised: 12/08/2022] [Accepted: 12/09/2022] [Indexed: 01/01/2023]
Abstract
Bimolecular reaction and collision complexes that drive atmospheric chemistry and contribute to the absorption of solar radiation are fleeting and therefore inherently challenging to study experimentally. Furthermore, primary anions in the troposphere are short lived because of a complicated web of reactions and complex formation they undergo, making details of their early fate elusive. In this perspective, the experimental approach of photodetaching mass-selected anion-molecule complexes or complex anions, which prepares neutrals in various vibronic states, is surveyed. Specifically, the application of anion photoelectron spectroscopy along with photoelectron-photofragment coincidence spectroscopy toward the study of collision complexes, complex anions in which a partial covalent bond is formed, and radical bimolecular reaction complexes, with relevance in tropospheric chemistry, will be highlighted.
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Affiliation(s)
- Caroline Chick Jarrold
- Department of Chemistry, Indiana
University, 800 East Kirkwood, Avenue
Bloomington, Indiana47405, United States
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4
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Sanov A. Intermolecular interactions in cluster anions. INT REV PHYS CHEM 2021. [DOI: 10.1080/0144235x.2021.1983292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Andrei Sanov
- Department of Chemistry and Biochemistry, The University of Arizona, Tucson, AZ, USA
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5
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Dauletyarov Y, Sanov A. Weak covalent interactions and anionic charge-sharing polymerisation in cluster environments. Phys Chem Chem Phys 2021; 23:11596-11610. [PMID: 33982051 DOI: 10.1039/d1cp01213d] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We discuss the formation of weak covalent bonds leading to anionic charge-sharing dimerisation or polymerisation in microscopic cluster environments. The covalent bonding between cluster building blocks is described in terms of coherent charge sharing, conceptualised using a coupled-monomers molecular-orbital model. The model assumes first-order separability of the inter- and intra-monomer bonding structures. Combined with a Hückel-style formalism adapted to weak covalent and solvation interactions, it offers insight into the competition between the two types of forces and illuminates the properties of the inter-monomer orbitals responsible for charge-sharing dimerisation and polymerisation. Under typical conditions, the cumulative effect of solvation obstructs the polymerisation, limiting the size of covalently bound core anions.
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Affiliation(s)
- Yerbolat Dauletyarov
- Department of Chemistry and Biochemistry, The University of Arizona, Tucson, Arizona 85721, USA.
| | - Andrei Sanov
- Department of Chemistry and Biochemistry, The University of Arizona, Tucson, Arizona 85721, USA.
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6
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Liu Y, Ning CG, Wang LS. Double- and multi-slit interference in photodetachment from nanometer organic molecular anions. J Chem Phys 2019; 150:244302. [DOI: 10.1063/1.5100799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Yuan Liu
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | - Chuan-Gang Ning
- State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 10084, China
- Collaborative Innovation Center of Quantum Matter, Beijing, China
| | - Lai-Sheng Wang
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
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7
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Dauletyarov Y, Wallace AA, Blackstone CC, Sanov A. Photoelectron Spectroscopy of Biacetyl and Its Cluster Anions. J Phys Chem A 2019; 123:4158-4167. [PMID: 31017789 DOI: 10.1021/acs.jpca.9b01302] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Photoelectron spectroscopy of the biacetyl (dimethylglyoxal) anion reveals the properties of the ground singlet and lowest triplet electronic states of the neutral biacetyl (BA) molecule. Due to the broad and congested nature of the singlet transition, which peaks at a vertical detachment energy VDE = 1.12(5) eV, only an upper bound of the adiabatic electron affinity of BA could be determined: EA(BA) < 0.7 eV. A narrower and more structured triplet band peaking at VDE = 3.17(2) eV reveals the adiabatic electron binding energy of the triplet to be 3.05(2) eV. These results are in good agreement with ab initio (coupled-cluster) calculations. The lowest-energy structures of the anion, singlet, and triplet states of biacetyl are characterized by different orientations of the methyl groups within the molecular frame. In the ground singlet state of neutral BA, the methyl torsion is offset by ∼60° compared to that of the anion, while in the triplet the methyl orientation is similar to that of the anion. Photoelectron spectra of the cluster anions reveal that the intermolecular interactions in the homogeneously solvated (BA) n- clusters are significantly stronger than the interactions of BA- with N2O or even of BA- with H2O. To account for these observations, π-π bonded structures of the dimer and trimer anions of biacetyl are proposed based on density-functional theory calculations. The analysis of the proposed structures indicates that the negative charge in the (BA) n- cluster anions, at least in the dimer and the trimer, is significantly delocalized between all BA moieties present and there is a significant degree of covalent bonding within the cluster.
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Affiliation(s)
- Yerbolat Dauletyarov
- Department of Chemistry and Biochemistry , The University of Arizona , Tucson , Arizona 85721 , United States
| | - Adam A Wallace
- Department of Chemistry and Biochemistry , The University of Arizona , Tucson , Arizona 85721 , United States
| | - Christopher C Blackstone
- Department of Chemistry and Biochemistry , The University of Arizona , Tucson , Arizona 85721 , United States
| | - Andrei Sanov
- Department of Chemistry and Biochemistry , The University of Arizona , Tucson , Arizona 85721 , United States
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8
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Watabe Y, Miyazaki T, Ozama E, Takayanagi T, Suzuki YI. Theoretical calculations of photoelectron spectrum of (Au–CO2)− anion. COMPUT THEOR CHEM 2018. [DOI: 10.1016/j.comptc.2018.07.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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9
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Dodson LG, Thompson MC, Weber JM. Characterization of Intermediate Oxidation States in CO2Activation. Annu Rev Phys Chem 2018; 69:231-252. [DOI: 10.1146/annurev-physchem-050317-021122] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Leah G. Dodson
- JILA and NIST, University of Colorado, Boulder, Colorado 80309-0440, USA
| | - Michael C. Thompson
- JILA and Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0440, USA;,
| | - J. Mathias Weber
- JILA and Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0440, USA;,
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10
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Craig SM, Johnson CJ, Ranasinghe DS, Perera A, Bartlett RJ, Berman MR, Johnson MA. Vibrational Characterization of Radical Ion Adducts between Imidazole and CO 2. J Phys Chem A 2018; 122:3805-3810. [PMID: 29608067 DOI: 10.1021/acs.jpca.8b01883] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We address the molecular level origins of the dramatic difference in the catalytic mechanisms of CO2 activation by the seemingly similar molecules pyridine (Py) and imidazole (Im). This is accomplished by comparing the fundamental interactions of CO2 radical anions with Py and Im in the isolated, gas phase PyCO2- and ImCO2- complexes. These species are prepared by condensation of the neutral compounds onto a (CO2) n- cluster ion beam by entrainment in a supersonic jet ion source. The structures of the anionic complexes are determined by theoretical analysis of their vibrational spectra, obtained by IR photodissociation of weakly bound CO2 molecules in a photofragmentation mass spectrometer. Although the radical PyCO2- system adopts a carbamate-like configuration corresponding to formation of an N-C covalent bond, the ImCO2- species is revealed to be best described as an ion-molecule complex in which an oxygen atom in the CO2- radical anion is H-bonded to the NH group. Species that feature a covalent N-C interaction in ImCO2- are calculated to be locally stable structures, but are much higher in energy than the largely electrostatically bound ion-molecule complex. These results support the suggestion from solution phase electrochemical studies (Bocarsly et al. ACS Catal. 2012, 2, 1684-1692) that the N atoms are not directly involved in the catalytic activation of CO2 by Im.
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Affiliation(s)
- Stephanie M Craig
- Sterling Chemistry Laboratory , Yale University , New Haven , Connecticut 06520 , United States
| | - Christopher J Johnson
- Department of Chemistry , Stony Brook University , Stony Brook , New York 11794 , United States
| | - Duminda S Ranasinghe
- Department of Chemistry , University of Florida , Gainesville , Florida 32611 , United States
| | - Ajith Perera
- Department of Chemistry , University of Florida , Gainesville , Florida 32611 , United States
| | - Rodney J Bartlett
- Department of Chemistry , University of Florida , Gainesville , Florida 32611 , United States
| | - Michael R Berman
- Air Force Office of Scientific Research , Arlington , Virginia 22203 , United States
| | - Mark A Johnson
- Sterling Chemistry Laboratory , Yale University , New Haven , Connecticut 06520 , United States
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11
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Thompson MC, Weber JM. Enhancement of infrared activity by moving electrons through bonds – The case of CO2 anion and carboxylate. Chem Phys Lett 2017. [DOI: 10.1016/j.cplett.2017.01.060] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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12
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The effects of water microsolvation on the C 2 O 4 − ↔ CO 2 ·CO 2 − core switching reaction: Perspective from exploration of pathways on the potential energy surfaces of small [(CO 2 ) 2 (H 2 O) n ] − ( n = 1 and 2) clusters. COMPUT THEOR CHEM 2017. [DOI: 10.1016/j.comptc.2017.02.020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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13
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Luzon I, Nagler M, Chandrasekaran V, Heber O, Strasser D. Near-Threshold Photodetachment Cross Section of (SF6)(n)(-) Cluster Anions: The Ion Core Structure. J Phys Chem A 2016; 120:221-6. [PMID: 26667587 DOI: 10.1021/acs.jpca.5b09967] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Photodetachment cross sections as a function of photon energy are measured for cold (SF6)n(-) cluster anions stored in an electrostatic ion beam trap. Absolute photodetachment cross sections near the adiabatic limit are reported. The strong dependence of the SF6(-) absolute photodetachment cross section on the anion equilibrium bond length leads to the conclusion that the excess charge is localized on a SF6(-) ion core that is only subtly perturbed by the neighboring cluster units.
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Affiliation(s)
- Itamar Luzon
- Institute of Chemistry, The Hebrew University of Jerusalem , Jerusalem 91904, Israel
| | - Maoz Nagler
- Institute of Chemistry, The Hebrew University of Jerusalem , Jerusalem 91904, Israel
| | | | - Oded Heber
- Department of Particle Physics, Weizmann Institute of Science , Rehovot 76100, Israel
| | - Daniel Strasser
- Institute of Chemistry, The Hebrew University of Jerusalem , Jerusalem 91904, Israel
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14
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Inokuchi Y, Ebata T. IR photodissociation spectroscopy of (OCS)n(+) and (OCS)n(-) cluster ions: Similarity and dissimilarity in the structure of CO2, OCS, and CS2 cluster ions. J Chem Phys 2015; 142:214306. [PMID: 26049495 DOI: 10.1063/1.4921991] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Infrared photodissociation (IRPD) spectra of (OCS)n(+) and (OCS)n(-) (n = 2-6) cluster ions are measured in the 1000-2300 cm(-1) region; these clusters show strong CO stretching vibrations in this region. For (OCS)2 +) and (OCS)2(-), we utilize the messenger technique by attaching an Ar atom to measure their IR spectra. The IRPD spectrum of (OCS)2 (+)Ar shows two bands at 2095 and 2120 cm(-1). On the basis of quantum chemical calculations, these bands are assigned to a C2 isomer of (OCS)2 (+), in which an intermolecular semi-covalent bond is formed between the sulfur ends of the two OCS components by the charge resonance interaction, and the positive charge is delocalized over the dimer. The (OCS)n(+) (n = 3-6) cluster ions show a few bands assignable to "solvent" OCS molecules in the 2000-2080 cm(-1) region, in addition to the bands due to the (OCS)2(+) ion core at ∼2090 and ∼2120 cm(-1), suggesting that the dimer ion core is kept in (OCS)3-6(+). For the (OCS)n(-) cluster anions, the IRPD spectra indicate the coexistence of a few isomers with an OCS(-) or (OCS)2(-) anion core over the cluster range of n = 2-6. The (OCS)2(-)Ar anion displays two strong bands at 1674 and 1994 cm(-1). These bands can be assigned to a Cs isomer with an OCS(-) anion core. For the n = 2-4 anions, this OCS(-) anion core form is dominant. In addition to the bands of the OCS(-) core isomer, we found another band at ∼1740 cm(-1), which can be assigned to isomers having an (OCS)2(-) ion core; this dimer core has C2 symmetry and (2)A electronic state. The IRPD spectra of the n = 3-6 anions show two IR bands at ∼1660 and ∼2020 cm(-1). The intensity of the latter component relative to that of the former one becomes stronger and stronger with increasing the size from n = 2 to 4, which corresponds to the increase of "solvent" OCS molecules attached to the OCS(-) ion core, but it suddenly decreases at n = 5 and 6. These IR spectral features of the n = 5 and 6 anions are ascribed to the formation of another (OCS)2(-) ion core having C2v symmetry with (2)B2 electronic state.
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Affiliation(s)
- Yoshiya Inokuchi
- Department of Chemistry, Graduate School of Science, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526, Japan
| | - Takayuki Ebata
- Department of Chemistry, Graduate School of Science, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526, Japan
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15
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Weber JM. The interaction of negative charge with carbon dioxide – insight into solvation, speciation and reductive activation from cluster studies. INT REV PHYS CHEM 2014. [DOI: 10.1080/0144235x.2014.969554] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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16
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Liu BK, Wang YQ, Wang L. Femtosecond Two-Photon Detachment of Cu −Studied By Photoelectron Imaging. CHINESE J CHEM PHYS 2014. [DOI: 10.1063/1674-0068/27/02/125-130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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17
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Liu P, Zhao J, Liu J, Zhang M, Bu Y. Ab initio molecular dynamics simulations reveal localization and time evolution dynamics of an excess electron in heterogeneous CO2–H2O systems. J Chem Phys 2014; 140:044318. [DOI: 10.1063/1.4863343] [Citation(s) in RCA: 11] [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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18
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Wang Z, Liu J, Zhang M, Cukier RI, Bu Y. Solvation and evolution dynamics of an excess electron in supercritical CO2. PHYSICAL REVIEW LETTERS 2012; 108:207601. [PMID: 23003186 DOI: 10.1103/physrevlett.108.207601] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2011] [Revised: 02/08/2012] [Indexed: 06/01/2023]
Abstract
We present an ab initio molecular dynamics simulation of the dynamics of an excess electron solvated in supercritical CO2. The excess electron can exist in three types of states: CO2-core localized, dual-core localized, and diffuse states. All these states undergo continuous state conversions via a combination of long lasting breathing oscillations and core switching, as also characterized by highly cooperative oscillations of the excess electron volume and vertical detachment energy. All of these oscillations exhibit a strong correlation with the electron-impacted bending vibration of the core CO2, and the core-switching is controlled by thermal fluctuations.
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Affiliation(s)
- Zhiping Wang
- The Center of Molecular Modeling & Simulation, Institute of Theoretical Chemistry, Shandong University, Jinan, 250100, People's Republic of China
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Sobhy MA, Casalenuovo K, Reveles JU, Gupta U, Khanna SN, Castleman AW. Photoelectron imaging and density-functional investigation of bismuth and lead anions solvated in ammonia clusters. J Phys Chem A 2010; 114:11353-63. [PMID: 20804193 DOI: 10.1021/jp1058148] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We present the results of photoelectron velocity-map imaging experiments for the photodetachment of small negatively charged ammonia solvated Bi(n) and Pb(n) (n = 1, 2) clusters at 527 nm. The vertical detachment energies of the observed multiple electronic bands and their respective anisotropy parameters for the solvated Bi and Pb anions and clusters derived from the photoelectron images are reported. The electronic bands of Bi(NH(3))(n=1,2) are distinct from the Bi metal ion in exhibiting a perpendicular distribution whereas the electronic bands in Pb(NH(3))(n=1,2), unlike the Pb anion, show an isotropic distribution with respect to the laser polarization. Density-functional theory calculations with a generalized gradient approximation for the exchange-correlation potential were performed on these clusters to determine their atomic and electronic structures. Calculated geometries show a dramatic change between anionic and neutral ammonia solvated Bi and Pb species. Anionic clusters exhibit van der Waals interactions between the hydrogen atoms of ammonia and the metal core, where it was determined that the negative charge is localized. Neutral clusters, on the other hand, present a covalent bond between the nitrogen atom of ammonia and the metal core. Calculated binding energies show an enhancement in the bonding of the (NH(3))(2) dimer in the presence of the anionic Bi(1,2)(-) and Pb(1,2)(-) metal ions. This is rationalized by the electrostatic interaction between the negative charged metal core and the hydrogen atoms of the ammonia molecule.
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Affiliation(s)
- Mohamed A Sobhy
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
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Muraoka A, Inokuchi Y, Hammer NI, Shin JW, Johnson MA, Nagata T. Structural evolution of the [(CO2)n(H2O)]- cluster anions: quantifying the effect of hydration on the excess charge accommodation motif. J Phys Chem A 2009; 113:8942-8. [PMID: 19603758 DOI: 10.1021/jp903578e] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The [(CO2)n(H2O)]- cluster anions are studied using infrared photodissociation (IPD) spectroscopy in the 2800-3800 cm(-1) range. The observed IPD spectra display a drastic change in the vibrational band features at n = 4, indicating a sharp discontinuity in the structural evolution of the monohydrated cluster anions. The n = 2 and 3 spectra are composed of a series of sharp bands around 3600 cm(-1), which are assignable to the stretching vibrations of H2O bound to C2O4- in a double ionic hydrogen-bonding (DIHB) configuration, as was previously discussed (J. Chem. Phys. 2005, 122, 094303). In the n > or = 4 spectrum, a pair of intense bands additionally appears at approximately 3300 cm(-1). With the aid of ab initio calculations at the MP2/6-31+G* level, the 3300 cm(-1) bands are assigned to the bending overtone and the hydrogen-bonded OH vibration of H2O bound to CO2- via a single O-H...O linkage. Thus, the structures of [(CO2)n(H2O)]- evolve with cluster size such that DIHB to C2O4- is favored in the smaller clusters with n = 2 and 3 whereas CO2- is preferentially stabilized via the formation of a single ionic hydrogen-bonding (SIHB) configuration in the larger clusters with n > or = 4.
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Affiliation(s)
- Azusa Muraoka
- Department of Basic Science, Graduate School of Arts and Sciences, The University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8902, Japan
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Inokuchi Y, Kobayashi Y, Muraoka A, Nagata T, Ebata T. Structures of water-CO2 and methanol-CO2 cluster ions: [H2O•(CO2)n]+ and [CH3OH•(CO2)n]+ (n=1–7). J Chem Phys 2009; 130:154304. [DOI: 10.1063/1.3116144] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
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22
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Sobhy MA, Reveles JU, Gupta U, Khanna SN, Castleman AW. Photoelectron imaging and theoretical investigation of bimetallic Bi1–2Ga0–2− and Pb1–4− cluster anions. J Chem Phys 2009; 130:054304. [DOI: 10.1063/1.3069295] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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23
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Goebbert DJ, Sanov A. Photodetachment, photofragmentation, and fragment autodetachment of [O[sub 2n](H[sub 2]O)[sub m]][sup −] clusters: Core-anion structures and fragment energy partitioning. J Chem Phys 2009. [DOI: 10.1063/1.3224135] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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24
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Kobayashi Y, Inokuchi Y, Ebata T. Ion core structure in (CS2)n+ and (CS2)n− (n=3–10) studied by infrared photodissociation spectroscopy. J Chem Phys 2008; 128:164319. [DOI: 10.1063/1.2913157] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Velarde L, Habteyes T, Grumbling ER, Pichugin K, Sanov A. Solvent resonance effect on the anisotropy of NO−(N2O)n cluster anion photodetachment. J Chem Phys 2007; 127:084302. [PMID: 17764243 DOI: 10.1063/1.2766948] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Photodetachment from NO(-)(N(2)O)(n) cluster anions (n< or =7) is investigated using photoelectron imaging at 786, 532, and 355 nm. Compared to unsolvated NO(-), the photoelectron anisotropy with respect to the laser polarization direction diminishes drastically in the presence of the N(2)O solvent, especially in the 355 nm data. In contrast, a less significant anisotropy loss is observed for NO(-)(H(2)O)(n). The effect is attributed to photoelectron scattering on the solvent, which in the N(2)O case is mediated by the (2)Pi anionic resonance. No anionic resonances exist for H(2)O in the applicable photoelectron energy range, in line with the observed difference between the photoelectron images obtained with the two solvents. The momentum-transfer cross section, rather than the total scattering cross section, is argued to be an appropriate physical parameter predicting the solvent effects on the photoelectron angular distributions in these cluster anions.
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Affiliation(s)
- Luis Velarde
- Department of Chemistry, University of Arizona, Tucson, Arizona 85721-0041, USA
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Sobhy MA, Castleman AW. Photoelectron imaging of copper and silver mono- and diamine anions. J Chem Phys 2007; 126:154314. [PMID: 17461633 DOI: 10.1063/1.2721566] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The results of photoelectron imaging experiments of Cu and Ag mono- and diamine anions are reported. The photoelectron images were recorded at two photon energies, 800 and 527 nm. The vertical detachment energies of CuNH(2) (-) and AgNH(2) (-) are lower than those of the respective atomic metal ion and are measured to be 1.11+/-0.05 and 1.23+/-0.05 eV, respectively. By contrast, the electron detachment energies for Cu(NH(2))(2) (-) and Ag(NH(2))(2) (-) are higher than those of the corresponding metal ion and are determined to be 1.48+/-0.05 and 1.85+/-0.05 eV, respectively. Energy-dependent photoelectron anisotropy parameters are also reported. The photodetachment of the Cu and Ag mono- and diamine anions exhibit a cos(2) theta angular dependence relative to the direction of the laser polarization. The nature of the chemical bonding and the symmetry of the highest occupied molecular orbitals are discussed in relevance to the measured anisotropy parameters.
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Affiliation(s)
- M A Sobhy
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, USA
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Habteyes T, Velarde L, Sanov A. Photodissociation of CO2− in water clusters via Renner-Teller and conical interactions. J Chem Phys 2007; 126:154301. [PMID: 17461620 DOI: 10.1063/1.2717932] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The photochemistry of mass selected CO(2) (-)(H2O)(m), m=2-40 cluster anions is investigated using 266 nm photofragment spectroscopy and theoretical calculations. Similar to the previous 355 nm experiment [Habteyes et al., Chem. Phys. Lett. 424, 268 (2006)], the fragmentation at 266 nm yields two types of anionic products: O(-)(H2O)(m-k) (core-dissociation products) and CO(2) (-)(H2O)(m-k) (solvent-evaporation products). Despite the same product types, different electronic transitions and dissociation mechanisms are implicated at 355 and 266 nm. The 355 nm dissociation is initiated by excitation to the first excited electronic state of the CO(2) (-) cluster core, the 1 (2)B(1)(2A") state, and proceeds via a glancing Renner-Teller intersection with the ground electronic state at a linear geometry. The 266 nm dissociation involves the second excited electronic state of CO(2) (-), the 2 (2)A(1)(2A') state, which exhibits a conical intersection with the 3 (2)B(2)(A') state at a bent geometry. The asymptotic O(-) based products are believed to be formed via this 3 (2)B(2)(A') state. By analyzing the fragmentation results, the bond dissociation energy of CO(2) (-) to O(-)+CO in hydrated clusters (m> or =20) is estimated as 2.49 eV, compared to 3.46 eV for bare CO(2) (-). The enthalpy of evaporation of one water molecule from asymptotically large CO(2) (-)(H(2)O)(m) clusters is determined to be 0.466+/-0.001 eV (45.0+/-0.1 kJ/mol). This result compares very favorably with the heat of evaporation of bulk water, 0.456 eV (43.98 kJ/mol).
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Affiliation(s)
- Terefe Habteyes
- Department of Chemistry, University of Arizona, 1306 E. University Boulevard, Tucson, AZ 85721-0041, USA
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Velarde L, Habteyes T, Sanov A. Photodetachment and photofragmentation pathways in the [(CO2)2(H2O)m]− cluster anions. J Chem Phys 2006; 125:114303. [PMID: 16999470 DOI: 10.1063/1.2347707] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The mass-selected [(CO(2))(2)(H(2)O)(m)](-) cluster anions are studied using a combination of photoelectron imaging and photofragment mass spectroscopy at 355 nm. Photoelectron imaging studies are carried out on the mass-selected parent cluster anions in the m=2-6 size range; photofragmentation results are presented for m=3-11. While the photoelectron images suggest possible coexistence of the CO(2) (-)(H(2)O)(m)CO(2) and (O(2)CCO(2))(-)(H(2)O)(m) parent cluster structures, particularly for m=2 and 3, only the CO(2) (-) based clusters are both required and sufficient to explain all fragmentation pathways for m>/=3. Three types of anionic photofragments are observed: CO(2) (-)(H(2)O)(k), O(-)(H(2)O)(k), and CO(3) (-)(H(2)O)(k), k</=m, with their yields varying depending on the parent cluster size. Of these, only CO(2) (-)(H(2)O)(k) can potentially result from (O(2)CCO(2))(-)(H(2)O)(m) parent structures, although an alternative mechanism, involving the dissociation and recombination of the CO(2) (-) cluster core, is possible as well. The O(-)(H(2)O)(k) and CO(3) (-)(H(2)O)(k) channels are believed to be triggered by the dissociation of the CO(2) (-) cluster core. In the CO(3) (-)(H(2)O)(k) channel, seen only in the range of m=3-6, the CO(2) (-) core dissociation is followed by an intracluster association of nascent O(-) with the solvent CO(2). This channel's absence in larger clusters (m>6) is attributed to hindrance from the H(2)O molecules.
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Affiliation(s)
- Luis Velarde
- Department of Chemistry, University of Arizona, Tucson, Arizona 85721-0041, USA
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Surber E, Mabbs R, Habteyes T, Sanov A. Photoelectron Imaging of Hydrated Carbon Dioxide Cluster Anions. J Phys Chem A 2005; 109:4452-8. [PMID: 16833780 DOI: 10.1021/jp050061p] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The effects of homogeneous and heterogeneous solvation on the electronic structure and photodetachment dynamics of hydrated carbon dioxide cluster anions are investigated using negative-ion photoelectron imaging spectroscopy. The experiments are conducted on mass-selected [(CO(2))(n)()(H(2)O)(m)()](-) cluster anions with n and m ranging up to 12 and 6, respectively, for selected clusters. Homogeneous solvation in (CO(2))(n)()(-) has minimal effect on the photoelectron angular distributions, despite dimer-to-monomer anion core switching. Heterogeneous hydration, on the other hand, is found to have the marked effect of decreasing the photodetachment anisotropy. For example, in the [CO(2)(H(2)O)(m)()](-) cluster anion series, the photoelectron anisotropy parameter falls to essentially zero with as few as 5-6 water molecules. The analysis of the data, supported by theoretical modeling, reveals that in the ground electronic state of the hydrated clusters the excess electron is localized on CO(2), corresponding to a (CO(2))(n)()(-).(H(2)O)(m)() configuration for all cluster anions studied. The diminishing anisotropy in the photoelectron images of hydrated cluster anions is proposed to be attributable to photoinduced charge transfer to solvent, creating transient (CO(2))(n)().(H(2)O)(m)()(-) states that subsequently decay via autodetachment.
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Affiliation(s)
- Eric Surber
- Department of Chemistry, University of Arizona, Tucson, Arizona 85721-0041, USA
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Shin JW, Hammer NI, Johnson MA, Schneider H, Glöss A, Weber JM. An Infrared Investigation of the (CO2)n- Clusters: Core Ion Switching from Both the Ion and Solvent Perspectives. J Phys Chem A 2005; 109:3146-52. [PMID: 16833642 DOI: 10.1021/jp050092k] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The (CO2)n- clusters are thought to accommodate the excess electron by forming a localized molecular anion, or "core ion", solvated by the remaining, largely neutral CO2 molecules. Earlier studies interpreted discontinuities in the (CO2)n- photoelectron spectra to indicate that both the CO2- and C2O4- species were present in a size-dependent fashion. Here we use vibrational predissociation spectroscopy to unambiguously establish the molecular structures of the core ions in the 2 < or = n < or = 17 size range. Spectra are reported in the 2300-3800 cm(-1) region, which allows us to independently monitor the contribution of each ion through its characteristic overtone and combination bands. These signature bands are observed to be essentially intact in the larger clusters, establishing that the CO2- and C2O4- molecular ions are indeed the only electron accommodation modes at play. The size dependence of the core ion suggested in earlier analyses of the photoelectron spectra is largely confirmed, although both species are present over a range of clusters near the expected critical cluster sizes, as opposed to the prompt changes inferred earlier. Perturbations in the bands associated with the nominally neutral CO2 "solvent" molecules are correlated with the changes in the molecular structure of the core ion. These observations are discussed in the context of a diabatic model for electron delocalization over the CO2 dimer. In this picture, the driving force leading to the transient formation of the monomer ion is traced to the solvent asymmetry inherent in an incomplete coordination shell.
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Affiliation(s)
- J-W Shin
- Sterling Chemistry Laboratory, Yale University, P. O. Box 208107, New Haven, Connecticut 06520
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Mabbs R, Surber E, Sanov A. Photoelectron anisotropy and channel branching ratios in the detachment of solvated iodide cluster anions. J Chem Phys 2005; 122:54308. [PMID: 15740323 DOI: 10.1063/1.1839861] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Photoelectron spectra and angular distributions in 267 nm detachment of the I(-)Ar, I(-)H(2)O, I(-)CH(3)I, and I(-)CH(3)CN cluster anions are examined in comparison with bare I(-) using velocity-map photoelectron imaging. In all cases, features are observed that correlate to two channels producing either I((2)P(3/2)) or I((2)P(1/2)). In the photodetachment of I(-) and I(-)Ar, the branching ratios of the (2)P(1/2) and (2)P(3/2) channels are observed to be approximately 0.4, in both cases falling short of the statistical ratio of 0.5. For I(-)H(2)O and I(-)CH(3)I, the (2)P(1/2) to (2)P(3/2) branching ratios are greater by a factor of 1.6 compared to the bare iodide case. The relative enhancement of the (2)P(1/2) channel is attributed to dipole effects on the final-state continuum wave function in the presence of polar solvents. For I(-)CH(3)CN the (2)P(1/2) to (2)P(3/2) ratio falls again, most likely due to the proximity of the detachment threshold in the excited spin-orbit channel. The photoelectron angular distributions in the photodetachment of I(-), I(-)Ar, I(-)H(2)O, and I(-)CH(3)CN are understood within the framework of direct detachment from I(-). Hence, the corresponding anisotropy parameters are modeled using variants of the Cooper-Zare central-potential model for atomic-anion photodetachment. In contrast, I(-)CH(3)I yields nearly isotropic photoelectron angular distributions in both detachment channels. The implications of this anomalous behavior are discussed with reference to alternative mechanisms, affording the solvent molecule an active role in the electron ejection process.
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Affiliation(s)
- Richard Mabbs
- Department of Chemistry, University of Arizona, Tucson, AZ 85721-0041, USA
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Bellm SM, Reid KL. Evaluation of the use of photoelectron imaging in obtaining photoelectron spectra and angular distributions: comparison with the field-free time-of-flight method. Chem Phys Lett 2004. [DOI: 10.1016/j.cplett.2004.07.088] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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