1
|
Palmer MH, Hoffmann SV, Jones NC, Coreno M, de Simone M, Grazioli C, Aitken RA, Perrault L, Patterson ILJ. The ultraviolet and vacuum ultraviolet absorption spectrum of gamma-pyrone; the singlet states studied by configuration interaction and density functional calculations. J Chem Phys 2024; 160:054305. [PMID: 38341687 DOI: 10.1063/5.0186919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Accepted: 01/05/2024] [Indexed: 02/13/2024] Open
Abstract
A synchrotron based vacuum ultraviolet absorption spectrum for γ-pyrone has been interpreted in terms of singlet excited electronic states using a variety of coupled cluster, configuration interaction, and density functional calculations. The extremely weak spectral onset at 3.557 eV shows eight vibrational peaks, which following previous analyses, are attributed to a forbidden 1A2 state. A contrasting broad peak with a maximum at 5.381 eV has a relatively high cross-section of 30 Mb; this arises from three overlapping states, where a 1A1 state dominates over progressively weaker 1B2 and 1B1 states. After fitting the second band to a polynomial Gaussian function and plotting the regular residuals over 20 vibrational peaks, we have had limited success in analyzing this fine structure. However, the small separation between these three states clearly shows that their vibrational satellites must overlap. Singlet valence and Rydberg state vibrational profiles were determined by configuration interaction using the CAM-B3LYP density functional. Vibrational analysis using both the Franck-Condon and Herzberg-Teller procedures showed that both procedures contributed to the profiles. Theoretical Rydberg states were evaluated by a highly focused CI procedure. The superposition of the lowest photoelectron spectral band on the vacuum ultraviolet spectrum near 6.4 eV shows that the 3s and 3p Rydberg states based on the 2B2 ionic state are present; those based on the other low-lying ionic state (X2B1) are destroyed by broadening; this is a dramatic extension of the broadening previously witnessed in our studies of halogenobenzenes.
Collapse
Affiliation(s)
- Michael H Palmer
- School of Chemistry, University of Edinburgh, Joseph Black Building, David Brewster Road, Edinburgh, EH9 3FJ Scotland, United Kingdom
| | - Søren Vrønning Hoffmann
- ISA, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C, Denmark
| | - Nykola C Jones
- ISA, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C, Denmark
| | - Marcello Coreno
- ISM-CNR, Instituto di Struttura della Materia, LD2 Unit, 34149 Trieste, Italy
| | - Monica de Simone
- IOM-CNR, Istituto Officina dei Materiali, Basovizza SS-14, Km 163.5, 34149 Trieste, Italy
| | - Cesare Grazioli
- IOM-CNR, Istituto Officina dei Materiali, Basovizza SS-14, Km 163.5, 34149 Trieste, Italy
| | - R Alan Aitken
- School of Chemistry, University of St Andrews, North Haugh, St Andrews, Fife, KY16 9ST Scotland, United Kingdom
| | - Loëlia Perrault
- School of Chemistry, University of St Andrews, North Haugh, St Andrews, Fife, KY16 9ST Scotland, United Kingdom
| | - Iain L J Patterson
- School of Chemistry, University of St Andrews, North Haugh, St Andrews, Fife, KY16 9ST Scotland, United Kingdom
| |
Collapse
|
2
|
Folkestad SD, Paul AC, Ponzi A, Grazioli C, Coreno M, de Simone M, Koch H, Coriani S. Electronic Characterization of Glycolaldehyde: Experimental and Theoretical Insights from the Core- and Valence-Level Spectroscopy. J Phys Chem A 2023; 127:10621-10631. [PMID: 38084657 DOI: 10.1021/acs.jpca.3c06703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2023]
Abstract
The core-level electron excitation and ionization spectra of glycolaldehyde have been investigated by photoabsorption and photoemission spectroscopy at both carbon and oxygen K-edges; the valence ionization spectra were also recorded by photoelectron spectroscopy in the UV-vis region. The spectra are interpreted by means of ab initio calculations based on the equation-of-motion coupled cluster singles and doubles (EOM-CCSD) and coupled cluster singles, doubles, and perturbative are in good agreement with the experimental results, and many of the observed features are assigned. The photoabsorption spectra are not only dominated by transitions from core-level orbitals to unoccupied π and σ orbitals but also show structures due to Rydberg transitions.
Collapse
Affiliation(s)
- Sarai Dery Folkestad
- Department of Chemistry, NTNU─Norwegian University of Science and Technology, Trondheim 7491, Norway
| | - Alexander C Paul
- Department of Chemistry, NTNU─Norwegian University of Science and Technology, Trondheim 7491, Norway
| | - Aurora Ponzi
- Department of Physical Chemistry, R. Bošković Institute, Bijenička Cesta 54, Zagreb 10000, Croatia
| | - Cesare Grazioli
- IOM-CNR, Istituto Officina dei Materiali del Consiglio Nazionale delle Ricerche, Basovizza Area Science Park, Trieste I-34149, Italy
| | - Marcello Coreno
- ISM-CNR, Istituto di Struttura della Materia del Consiglio Nazionale delle Ricerche, Basovizza Area Science Park, Trieste I-34149, Italy
| | - Monica de Simone
- IOM-CNR, Istituto Officina dei Materiali del Consiglio Nazionale delle Ricerche, Basovizza Area Science Park, Trieste I-34149, Italy
| | - Henrik Koch
- Department of Chemistry, NTNU─Norwegian University of Science and Technology, Trondheim 7491, Norway
| | - Sonia Coriani
- DTU Chemistry, Technical University of Denmark, Kemitorvet Bldg 207, Kgs. Lyngby DK-2800, Denmark
| |
Collapse
|
3
|
Epshtein M, Tenorio BNC, Vidal ML, Scutelnic V, Yang Z, Xue T, Krylov AI, Coriani S, Leone SR. Signatures of the Bromine Atom and Open-Shell Spin Coupling in the X-ray Spectrum of the Bromobenzene Cation. J Am Chem Soc 2023; 145:3554-3560. [PMID: 36735829 DOI: 10.1021/jacs.2c12334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Tabletop X-ray spectroscopy measurements at the carbon K-edge complemented by ab initio calculations are used to investigate the influence of the bromine atom on the carbon core-valence transitions in the bromobenzene cation (BrBz+). The electronic ground state of the cation is prepared by resonance-enhanced two-photon ionization of neutral bromobenzene (BrBz) and probed by X-rays produced by high-harmonic generation (HHG). Replacing one of the hydrogen atoms in benzene with a bromine atom shifts the transition from the 1sC* orbital of the carbon atom (C*) bonded to bromine by ∼1 eV to higher energy in the X-ray spectrum compared to the other carbon atoms (C). Moreover, in BrBz+, the X-ray spectrum is dominated by two relatively intense transitions, 1sC→π* and 1sC*→σ*(C*-Br), where the second transition is enhanced relative to the neutral BrBz. In addition, a doublet peak shape for these two transitions is observed in the experiment. The 1sC→π* doublet peak shape arises due to the spin coupling of the unpaired electron in the partially vacant π orbital (from ionization) with the two other unpaired electrons resulting from the transition from the 1sC core orbital to the fully vacant π* orbitals. The 1sC*→σ* doublet peak shape results from several transitions involving σ* and vibrational C*-Br mode activations following the UV ionization, which demonstrates the impact of the C*-Br bond length on the core-valence transition as well as on the relaxation geometry of BrBz+.
Collapse
Affiliation(s)
- Michael Epshtein
- Department of Chemistry, University of California, Berkeley, California 94720, United States.,Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | | | - Marta L Vidal
- DTU Chemistry─Department of Chemistry, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark
| | - Valeriu Scutelnic
- Department of Chemistry, University of California, Berkeley, California 94720, United States.,Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Zheyue Yang
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Tian Xue
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Anna I Krylov
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, United States
| | - Sonia Coriani
- DTU Chemistry─Department of Chemistry, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark
| | - Stephen R Leone
- Department of Chemistry, University of California, Berkeley, California 94720, United States.,Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.,Department of Physics, University of California, Berkeley, California 94720, United States
| |
Collapse
|
4
|
Park Y, Park S, Shin J, Lim M. Photodissociation dynamics of chlorobenzene and
4‐fluoroiodobenzene
in
CCl
4
probed using time‐resolved infrared spectroscopy. B KOREAN CHEM SOC 2022. [DOI: 10.1002/bkcs.12495] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Yejin Park
- Department of Chemistry and Chemical Institute for Functional Materials Pusan National University Busan Korea
| | - Seongchul Park
- Department of Chemistry and Chemical Institute for Functional Materials Pusan National University Busan Korea
| | - Juhyang Shin
- Department of Chemistry and Chemical Institute for Functional Materials Pusan National University Busan Korea
| | - Manho Lim
- Department of Chemistry and Chemical Institute for Functional Materials Pusan National University Busan Korea
| |
Collapse
|
5
|
Mendes M, Kossoski F, Lozano AI, Pereira-da-Silva J, Rodrigues R, Ameixa J, Jones NC, Hoffmann SV, Ferreira da Silva F. Excited States of Bromopyrimidines Probed by VUV Photoabsorption Spectroscopy and Theoretical Calculations. Int J Mol Sci 2021; 22:6460. [PMID: 34208711 PMCID: PMC8235550 DOI: 10.3390/ijms22126460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 06/10/2021] [Accepted: 06/12/2021] [Indexed: 11/16/2022] Open
Abstract
We report absolute photoabsorption cross sections for gas-phase 2- and 5-bromopyrimidine in the 3.7-10.8 eV energy range, in a joint theoretical and experimental study. The measurements were carried out using high-resolution vacuum ultraviolet synchrotron radiation, with quantum chemical calculations performed through the nuclear ensemble approach in combination with time-dependent density functional theory, along with additional Franck-Condon Herzberg-Teller calculations for the first absorption band (3.7-4.6 eV). The cross sections of both bromopyrimidines are very similar below 7.3 eV, deviating more substantially from each other at higher energies. In the 7.3-9.0 eV range where the maximum cross-section is found, a single and broad band is observed for 5-bromopyrimidine, while more discernible features appear in the case of 2-bromopyrimidine. Several π* ← π transitions account for the most intense bands, while weaker ones are assigned to transitions involving the nitrogen and bromine lone pairs, the antibonding σ*Br orbital, and the lower-lying Rydberg states. A detailed comparison with the available photo-absorption data of bromobenzene is also reported. We have found significant differences regarding the main absorption band, which is more peaked in bromobenzene, becoming broader and shifting to higher energies in both bromopyrimidines. In addition, there is a significant suppression of vibrational structures and of Rydberg states in the pair of isomers, most noticeably for 2-bromopyrimidine.
Collapse
Affiliation(s)
- Mónica Mendes
- CEFITEC, Departamento de Física, NOVA School of Science and Technology, FCT NOVA, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal; (A.I.L.); (J.P.-d.-S.); (R.R.); (J.A.); (F.F.d.S.)
| | - Fábris Kossoski
- Laboratoire de Chimie et Physique Quantiques (UMR 5626), Université de Toulouse, CNRS, UPS, CEDEX 09, 31062 Toulouse, France
| | - Ana I. Lozano
- CEFITEC, Departamento de Física, NOVA School of Science and Technology, FCT NOVA, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal; (A.I.L.); (J.P.-d.-S.); (R.R.); (J.A.); (F.F.d.S.)
| | - João Pereira-da-Silva
- CEFITEC, Departamento de Física, NOVA School of Science and Technology, FCT NOVA, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal; (A.I.L.); (J.P.-d.-S.); (R.R.); (J.A.); (F.F.d.S.)
| | - Rodrigo Rodrigues
- CEFITEC, Departamento de Física, NOVA School of Science and Technology, FCT NOVA, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal; (A.I.L.); (J.P.-d.-S.); (R.R.); (J.A.); (F.F.d.S.)
| | - João Ameixa
- CEFITEC, Departamento de Física, NOVA School of Science and Technology, FCT NOVA, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal; (A.I.L.); (J.P.-d.-S.); (R.R.); (J.A.); (F.F.d.S.)
| | - Nykola C. Jones
- ISA, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, 8000 Aarhus C, Denmark; (N.C.J.); (S.V.H.)
| | - Søren V. Hoffmann
- ISA, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, 8000 Aarhus C, Denmark; (N.C.J.); (S.V.H.)
| | - Filipe Ferreira da Silva
- CEFITEC, Departamento de Física, NOVA School of Science and Technology, FCT NOVA, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal; (A.I.L.); (J.P.-d.-S.); (R.R.); (J.A.); (F.F.d.S.)
| |
Collapse
|
6
|
Paoloni L, Fusè M, Baiardi A, Barone V. Interplay of Stereoelectronic and Vibrational Modulation Effects in Tuning the UPS Spectra of Unsaturated Hydrocarbon Cage Compounds. J Chem Theory Comput 2020; 16:5218-5226. [PMID: 32667793 PMCID: PMC8009518 DOI: 10.1021/acs.jctc.0c00645] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Indexed: 11/28/2022]
Abstract
The UPS spectra of six hydrocarbon cage compounds have been investigated by a Green-function approach in conjunction with a full harmonic treatment of vibrational modulation effects. The remarkable agreement with experimental results points out the reliability of the proposed computational approach and the strong interplay of stereoelectronic and vibrational effects in tuning the overall spectra.
Collapse
Affiliation(s)
- Lorenzo Paoloni
- Scuola
Normale Superiore, Piazza dei Cavalieri 7, 56125 Pisa, Italy
| | - Marco Fusè
- Scuola
Normale Superiore, Piazza dei Cavalieri 7, 56125 Pisa, Italy
| | - Alberto Baiardi
- Lab.
für Physikalische Chemie, Vladimir-Prelog-Weg 1-5/10, 8093 Zürich, Switzerland
| | - Vincenzo Barone
- Scuola
Normale Superiore, Piazza dei Cavalieri 7, 56125 Pisa, Italy
| |
Collapse
|
7
|
Auburger P, Kemeny I, Bertram C, Ligges M, Bockstedte M, Bovensiepen U, Morgenstern K. Microscopic Insight into Electron-Induced Dissociation of Aromatic Molecules on Ice. PHYSICAL REVIEW LETTERS 2018; 121:206001. [PMID: 30500234 DOI: 10.1103/physrevlett.121.206001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Indexed: 06/09/2023]
Abstract
We use scanning tunneling microscopy, photoelectron spectroscopy, and ab initio calculations to investigate the electron-induced dissociation of halogenated benzene molecules adsorbed on ice. Dissociation of halobenzene is triggered by delocalized excess electrons attaching to the π^{*} orbitals of the halobenzenes from where they are transferred to σ^{*} orbitals. The latter orbitals provide a dissociative potential surface. Adsorption on ice sufficiently lowers the energy barrier for the transfer between the orbitals to facilitate dissociation of bromo- and chloro- but not of flourobenzene at cryogenic temperatures. Our results shed light on the influence of environmentally important ice particles on the reactivity of halogenated aromatic molecules.
Collapse
Affiliation(s)
- Philipp Auburger
- Solid State Theory, Friedrich-Alexander University Erlangen-Nürnberg, Staudstr. 7B2, D-91058 Erlangen, Germany
| | - Ishita Kemeny
- Faculty of Physics, University of Duisburg-Essen, Lotharstr. 1, D-47057 Duisburg, Germany
| | - Cord Bertram
- Faculty of Physics, University of Duisburg-Essen, Lotharstr. 1, D-47057 Duisburg, Germany
- Physical Chemistry I, Ruhr-Universität Bochum, Universitätsstr. 150, D-44801 Bochum, Germany
| | - Manuel Ligges
- Faculty of Physics, University of Duisburg-Essen, Lotharstr. 1, D-47057 Duisburg, Germany
| | - Michel Bockstedte
- Solid State Theory, Friedrich-Alexander University Erlangen-Nürnberg, Staudstr. 7B2, D-91058 Erlangen, Germany
- Department of Chemistry and Physics of Materials, Paris-Lodron University Salzburg, Jakob-Haringer-Str. 2a, A-5020 Salzburg, Austria
| | - Uwe Bovensiepen
- Faculty of Physics, University of Duisburg-Essen, Lotharstr. 1, D-47057 Duisburg, Germany
| | - Karina Morgenstern
- Physical Chemistry I, Ruhr-Universität Bochum, Universitätsstr. 150, D-44801 Bochum, Germany
| |
Collapse
|
8
|
Palmer MH, Hoffmann SV, Jones NC, Coreno M, de Simone M, Grazioli C, Peterson KA, Baiardi A, Zhang T, Biczysko M. A combined theoretical and experimental study of the valence and Rydberg states of iodopentafluorobenzene. J Chem Phys 2018; 146:174301. [PMID: 28477584 DOI: 10.1063/1.4981919] [Citation(s) in RCA: 5] [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 new ultraviolet (UV) and vacuum ultraviolet (VUV) spectrum for iodopentafluorobenzene (C6F5I) using synchrotron radiation is reported. The measurements have been combined with those from a recent high-resolution photoelectron spectroscopic study. A major theoretical study, which includes both Franck-Condon (FC) and Herzberg-Teller (HT) analyses, leads to conclusions, which are compatible with both experimental studies. Our observation that the VUV multiplet at 7.926 eV in the VUV spectrum is a Rydberg state rather than a valence state leads to a fundamental reassignment of the VUV Rydberg spectrum over previous studies and removes an anomaly where some previously assigned Rydberg states were to optically forbidden states. Adiabatic excitation energies (AEEs) were determined from equations-of-motion coupled cluster with singles and doubles excitation; these were combined with time dependent density functional theoretical methods. Frequencies from these two methods are very similar, and this enabled the evaluation of both FC and HT contributions in the lower valence states. Multi-reference multi-root configuration interaction gave a satisfactory account of the principal UV+VUV spectral profile of C6F5I, with vertical band positions and intensities. The UV spectral onset consists of two very weak transitions assigned to 11B1 (πσ*) and 11B2 (σσ*) symmetries. The lowest unoccupied molecular orbital of a σ*(a1) symmetry has a significant C-I* antibonding character. This results in considerable lengthening of the C-I bond for both these excited states. The vibrational intensity of the lowest 11B1 state is dominated by HT contributions; the 11B2 state contains both HT and FC contributions; the third band, which contains three states, two ππ*(11A1, 21B2) and one πσ*(21B1), is dominated by FC contributions in the 1A1 state. In this 1A1 state, and the spectrally dominant bands near 6.7 (1A1) and 7.3 eV (1A1 + 1B2), the C-I bond length is in the normal range, and FC components dominate.
Collapse
Affiliation(s)
- Michael H Palmer
- School of Chemistry, University of Edinburgh, Joseph Black Building, David Brewster Road, Edinburgh, EH9 3FJ Scotland, United Kingdom
| | - Søren Vrønning Hoffmann
- ISA, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C, Denmark
| | - Nykola C Jones
- ISA, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C, Denmark
| | | | | | | | - Kirk A Peterson
- Department of Chemistry, Washington State University, Pullman, Washington 99164-4630, USA
| | - Alberto Baiardi
- Scuola Normale Superiore, Piazza Cavalieri 7, 56126 Pisa, Italy
| | - Teng Zhang
- Department of Physics and Astronomy, University of Uppsala, Uppsala, Sweden
| | - Malgorzata Biczysko
- International Centre for Quantum and Molecular Structures, College of Sciences, Shanghai University, 99 Shangda Road, Shanghai 200444, China
| |
Collapse
|
9
|
A comparative study of the structures and electronic properties of graphene fragments: A DFT and MP2 survey. Chem Phys Lett 2018. [DOI: 10.1016/j.cplett.2017.11.023] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
10
|
Baiardi A, Paoloni L, Barone V, Zakrzewski VG, Ortiz JV. Assessment of Electron Propagator Methods for the Simulation of Vibrationally Resolved Valence and Core Photoionization Spectra. J Chem Theory Comput 2017; 13:3120-3135. [PMID: 28521087 PMCID: PMC5732571 DOI: 10.1021/acs.jctc.6b00958] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The analysis of photoelectron spectra is usually facilitated by quantum mechanical simulations. Because of the recent improvement of experimental techniques, the resolution of experimental spectra is rapidly increasing, and the inclusion of vibrational effects is usually mandatory to obtain a reliable reproduction of the spectra. With the aim of defining a robust computational protocol, a general time-independent formulation to compute different kinds of vibrationally resolved electronic spectra has been generalized to also support photoelectron spectroscopy. The electronic structure data underlying the simulation are computed using different electron propagator approaches. In addition to the more standard approaches, a new and robust implementation of the second-order self-energy approximation of the electron propagator based on a transition operator reference (TOEP2) is presented. To validate our implementation, a series of molecules has been used as test cases. The result of the simulations shows that, for ultraviolet photoionization spectra, the more accurate nondiagonal approaches are needed to obtain a reliable reproduction of vertical ionization energies but that diagonal approaches are sufficient for energy gradients and pole strengths. For X-ray photoelectron spectroscopy, the TOEP2 approach, besides being more efficient, is also the most accurate in the reproduction of both vertical ionization energies and vibrationally resolved bandshapes.
Collapse
Affiliation(s)
- A Baiardi
- Scuola Normale Superiore , Piazza dei Cavalieri 7, I-56126 Pisa, Italy
| | - L Paoloni
- Scuola Normale Superiore , Piazza dei Cavalieri 7, I-56126 Pisa, Italy
| | - V Barone
- Scuola Normale Superiore , Piazza dei Cavalieri 7, I-56126 Pisa, Italy
| | - V G Zakrzewski
- Department of Chemistry and Biochemistry, Auburn University , Auburn, Alabama 36849-5312, United States
| | - J V Ortiz
- Department of Chemistry and Biochemistry, Auburn University , Auburn, Alabama 36849-5312, United States
| |
Collapse
|
11
|
Palmer MH, Coreno M, de Simone M, Hoffmann SV, Jones NC, Grazioli C, Peterson KA, Baiardi A, Zhang T, Biczysko M. A combined theoretical and experimental study of the ionic states of iodopentafluorobenzene. J Chem Phys 2017; 146:084302. [PMID: 28249445 DOI: 10.1063/1.4975672] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A new synchrotron radiation photoelectron spectral (PES) study of iodopentafluorobenzene, together with a theoretical analysis of the spectrum, where Franck-Condon factors are discussed, gives detailed insight into the ionization processes, and this exposes the need for a reinvestigation of the vacuum ultraviolet spectral (VUV) assignments. We have calculated adiabatic ionization energies (AIEs) for several ionic states, using the equation-of-motion coupled cluster method for ionic states combined with multi-configuration self-consistent field calculation study. The AIE sequence is: X2B1 < A2A2 < B2B2 < C22B1 < D2A1 < E32B1. This symmetry sequence has a major impact on previous VUV spectral assignments, which now appear to be to optically forbidden states. Changes in the equilibrium structures for these ionic states are relatively small, but a significant decrease and increase in the C-I bond length relative to the X1A1 structure occurs for the X2B1 and C2B1 states, respectively. The PES shows major vibrational overlaps between pairs of ionic states, X with A, and A with B. The result of these overlaps is the loss of vibrational structure and considerable broadening of the higher energy PES state. Although the baseline is nearly re-established between the A and B states, where the two bands are nearly separate, the B state is also broadened by the A state. Only the C ionic state, which shows the most highly developed vibrational structure, can be regarded as free from vibrational coupling to a neighbor state. The Franck-Condon analysis of the PES bands X, A, B, and C is described in detail; the apparent simplicity of some of these bands is illusory, since almost all the observed peaks arise from super-position of several calculated vibrational states. The experimental AIE of the A state, which is submerged under the X state envelope, has been determined by the subtraction of the calculated X state envelope from the observed PES spectrum. The overlap of these PES bands and the apparent closeness of the potential energy curves describing them have been investigated, using the state-averaged, complete active space self-consistent field method. We have identified two structures, one where the potential energy curves for the X and A states cross and another for the A and B states. At these two conical intersections (ConInts), there is zero-energy difference within each pair of states. Although similar in energy, the ConInt for the crossing of the X with A states, and that for the A with B states, shows that the open-shell occupancies correspond to the 4 lowest AIE states, and all four states that are quite different from each other.
Collapse
Affiliation(s)
- Michael H Palmer
- School of Chemistry, University of Edinburgh, Joseph Black Building, David Brewster Road, Edinburgh EH9 3FJ, Scotland, United Kingdom
| | - Marcello Coreno
- CNR-IMIP, Montelibretti, c/o Laboratorio Elettra, Trieste, Italy
| | | | - Søren Vrønning Hoffmann
- ISA, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C, Denmark
| | - Nykola C Jones
- ISA, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C, Denmark
| | - Cesare Grazioli
- CNR-IMIP, Montelibretti, c/o Laboratorio Elettra, Trieste, Italy
| | - Kirk A Peterson
- Department of Chemistry, Washington State University, Pullman, Washington 99164-4630, USA
| | - Alberto Baiardi
- Scuola Normale Superiore, Piazza Cavalieri 7, 56126 Pisa, Italy
| | - Teng Zhang
- Department of Physics and Astronomy, University of Uppsala, Uppsala, Sweden
| | - Malgorzata Biczysko
- International Centre for Quantum and Molecular Structures, College of Sciences, Shanghai University, 99 Shangda Road, Shanghai 200444, China
| |
Collapse
|
12
|
Palmer MH, Ridley T, Vrønning Hoffmann S, Jones NC, Coreno M, de Simone M, Grazioli C, Zhang T, Biczysko M, Baiardi A, Peterson KA. Combined theoretical and experimental study of the valence, Rydberg and ionic states of fluorobenzene. J Chem Phys 2016; 144:204305. [PMID: 27250304 DOI: 10.1063/1.4949548] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
New photoelectron spectra (PES) and ultra violet (UV) and vacuum UV (VUV) absorption spectra of fluorobenzene recorded at higher resolution than previously, have been combined with mass-resolved (2 + 1) and (3 + 1) resonance enhanced multiphoton ionization (REMPI) spectra; this has led to the identification of numerous Rydberg states. The PES have been compared with earlier mass-analyzed threshold ionization and photoinduced Rydberg ionization (PIRI) spectra to give an overall picture of the ionic state sequence. The analysis of these spectra using both equations of motion with coupled cluster singles and doubles (EOM-CCSD) configuration interaction and time dependent density functional theory (TDDFT) calculations have been combined with vibrational analysis of both the hot and cold bands of the spectra, in considerable detail. The results extend several earlier studies on the vibronic coupling leading to conical intersections between the X(2)B1 and A(2)A2 states, and a further trio (B, C, and D) of states. The conical intersection of the X and A states has been explicitly identified, and its structure and energetics evaluated. The energy sequence of the last group is only acceptable to the present study if given as B(2)B2<C(2)B1<D(2)A1, a conclusion which is in agreement with most previous EOM-CCSD and other calculations. However, this symmetry ordering of the B and C states forces reconsideration of the nature of the PIRI spectrum. The coupling between these two states is induced by the a2 modes, ν12 and ν14 and we propose that the 14(1) band is observed in the B(2)B2 band in the PES for the first time, because of the improved resolution. This same assignment is given to the lowest energy band in the PIRI spectrum which was previously assigned as the origin band and further conclude that the entire PIRI spectrum is induced by ν12 and ν14. The relative intensities of the various Rydberg state peaks in the VUV absorption and REMPI spectra of fluorobenzene are very similar to those observed in the equivalent spectra of benzene.
Collapse
Affiliation(s)
- Michael H Palmer
- School of Chemistry, University of Edinburgh, Joseph Black Building, David Brewster Road, Edinburgh, Scotland EH9 3FJ, United Kingdom
| | - Trevor Ridley
- School of Chemistry, University of Edinburgh, Joseph Black Building, David Brewster Road, Edinburgh, Scotland EH9 3FJ, United Kingdom
| | - Søren Vrønning Hoffmann
- ISA, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C, Denmark
| | - Nykola C Jones
- ISA, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C, Denmark
| | - Marcello Coreno
- CNR-ISM, Basovizza Area Science Park, 1-34149 Trieste, Italy
| | | | | | - Teng Zhang
- Department of Physics and Astronomy, University of Uppsala, Uppsala, Sweden
| | - Malgorzata Biczysko
- International Centre for Quantum and Molecular Structures, College of Sciences, Shanghai University, 99 Shangda Road, Shanghai 200444, China
| | - Alberto Baiardi
- Scuola Normale Superiore, Piazza Cavalieri 7, 56126 Pisa, Italy
| | - Kirk A Peterson
- Department of Chemistry, Washington State University, Pullman, Washington 99164-4630, USA
| |
Collapse
|
13
|
Palmer MH, Ridley T, Vrønning Hoffmann S, Jones NC, Coreno M, de Simone M, Grazioli C, Zhang T, Biczysko M, Baiardi A, Peterson KA. Combined theoretical and experimental study of the valence, Rydberg, and ionic states of chlorobenzene. J Chem Phys 2016; 144:124302. [PMID: 27036443 DOI: 10.1063/1.4944078] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
New photoelectron (PE) and ultra violet (UV) and vacuum UV (VUV) spectra have been obtained for chlorobenzene by synchrotron study with higher sensitivity and resolution than previous work and are subjected to detailed analysis. In addition, we report on the mass-resolved (2 + 1) resonance enhanced multiphoton ionization (REMPI) spectra of a jet-cooled sample. Both the VUV and REMPI spectra have enabled identification of a considerable number of Rydberg states for the first time. The use of ab initio calculations, which include both multi-reference multi-root doubles and singles configuration interaction (MRD-CI) and time dependent density functional theoretical (TDDFT) methods, has led to major advances in interpretation of the vibrational structure of the ionic and electronically excited states. Franck-Condon (FC) analyses of the PE spectra, including both hot and cold bands, indicate much more complex envelopes than previously thought. The sequence of ionic states can be best interpreted by our multi-configuration self-consistent field computations and also by comparison of the calculated vibrational structure of the B and C ionic states with experiment; these conclusions suggest that the leading sequence is the same as that of iodobenzene and bromobenzene, namely: X(2)B1(3b1 (-1)) < A(2)A2(1a2 (-1)) < B(2)B2(6b2 (-1)) < C(2)B1(2b1 (-1)). The absorption onset near 4.6 eV has been investigated using MRD-CI and TDDFT calculations; the principal component of this band is (1)B2 and an interpretation based on the superposition of FC and Herzberg-Teller contributions has been performed. The other low-lying absorption band near 5.8 eV is dominated by a (1)A1 state, but an underlying weak (1)B1 state (πσ(∗)) is also found. The strongest band in the VUV spectrum near 6.7 eV is poorly resolved and is analyzed in terms of two ππ(∗) states of (1)A1 (higher oscillator strength) and (1)B2 (lower oscillator strength) symmetries, respectively. The calculated vertical excitation energies of these two states are critically dependent upon the presence of Rydberg functions in the basis set, since both manifolds are strongly perturbed by the Rydberg states in this energy range. A number of equilibrium structures of the ionic and singlet excited states show that the molecular structure is less subject to variation than corresponding studies for iodobenzene and bromobenzene.
Collapse
Affiliation(s)
- Michael H Palmer
- School of Chemistry, University of Edinburgh, Joseph Black Building, David Brewster Road, Edinburgh EH9 3FJ, Scotland
| | - Trevor Ridley
- School of Chemistry, University of Edinburgh, Joseph Black Building, David Brewster Road, Edinburgh EH9 3FJ, Scotland
| | - Søren Vrønning Hoffmann
- ISA, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C, Denmark
| | - Nykola C Jones
- ISA, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C, Denmark
| | - Marcello Coreno
- CNR-ISM, Basovizza Area Science Park, 1-34149 Trieste, Italy
| | | | | | - Teng Zhang
- Department of Physics and Astronomy, University of Uppsala, Uppsala, Sweden
| | - Malgorzata Biczysko
- International Centre for Quantum and Molecular Structures, College of Sciences, Shanghai University, 99 Shangda Road, Shanghai 200444, China
| | - Alberto Baiardi
- Scuola Normale Superiore, Piazza Cavalieri 7, 56126 Pisa, Italy
| | - Kirk A Peterson
- Department of Chemistry, Washington State University, Pullman, Washington 99164-4630, USA
| |
Collapse
|
14
|
Andrejeva A, Tuttle WD, Harris JP, Wright TG. Resonance-enhanced multiphoton ionization (REMPI) spectroscopy of bromobenzene and its perdeuterated isotopologue: Assignment of the vibrations of the S0, S1, and D0+ states of bromobenzene and the S0 and D0+ states of iodobenzene. J Chem Phys 2015; 143:244320. [DOI: 10.1063/1.4938501] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Anna Andrejeva
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
| | - William D. Tuttle
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
| | - Joe P. Harris
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
| | - Timothy G. Wright
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
| |
Collapse
|