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Søren Vrønning Hoffmann

The photoelectron spectra of the isomeric 1-and 2-methyltetrazoles; their equilibrium structures and vibrational analysis by ab initio calculations

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The photoelectron spectra of the isomeric 1-and 2-methyltetrazoles; their equilibrium structures and vibrational analysis by ab initio calculations. / Palmer, Michael H.; Coreno, Marcello; de Simone, Monica; Grazioli, Cesare; Hoffmann, Soren Vronning; Jones, Nykola C.; Peterson, Kirk A.; Aitken, R. Alan; Rouxel, Cecile.

I: Journal of Chemical Physics, Bind 149, Nr. 3, 034305, 21.07.2018.

Publikation: Bidrag til tidsskrift/Konferencebidrag i tidsskrift /Bidrag til avisTidsskriftartikelForskningpeer review

Harvard

Palmer, MH, Coreno, M, de Simone, M, Grazioli, C, Hoffmann, SV, Jones, NC, Peterson, KA, Aitken, RA & Rouxel, C 2018, 'The photoelectron spectra of the isomeric 1-and 2-methyltetrazoles; their equilibrium structures and vibrational analysis by ab initio calculations', Journal of Chemical Physics, bind 149, nr. 3, 034305. https://doi.org/10.1063/1.5041249

APA

Palmer, M. H., Coreno, M., de Simone, M., Grazioli, C., Hoffmann, S. V., Jones, N. C., Peterson, K. A., Aitken, R. A., & Rouxel, C. (2018). The photoelectron spectra of the isomeric 1-and 2-methyltetrazoles; their equilibrium structures and vibrational analysis by ab initio calculations. Journal of Chemical Physics, 149(3), [034305]. https://doi.org/10.1063/1.5041249

CBE

Palmer MH, Coreno M, de Simone M, Grazioli C, Hoffmann SV, Jones NC, Peterson KA, Aitken RA, Rouxel C. 2018. The photoelectron spectra of the isomeric 1-and 2-methyltetrazoles; their equilibrium structures and vibrational analysis by ab initio calculations. Journal of Chemical Physics. 149(3):Article 034305. https://doi.org/10.1063/1.5041249

MLA

Vancouver

Author

Palmer, Michael H. ; Coreno, Marcello ; de Simone, Monica ; Grazioli, Cesare ; Hoffmann, Soren Vronning ; Jones, Nykola C. ; Peterson, Kirk A. ; Aitken, R. Alan ; Rouxel, Cecile. / The photoelectron spectra of the isomeric 1-and 2-methyltetrazoles; their equilibrium structures and vibrational analysis by ab initio calculations. I: Journal of Chemical Physics. 2018 ; Bind 149, Nr. 3.

Bibtex

@article{661b8350cae64a5c8a7d531d2c666ac9,
title = "The photoelectron spectra of the isomeric 1-and 2-methyltetrazoles; their equilibrium structures and vibrational analysis by ab initio calculations",
abstract = "New synchrotron based studies of the photoelectron ionization spectra (PES) for the isomeric 1- and 2-methyltetrazoles (1- and 2-MeTet) show markedly higher resolution than previous reports. The unusual spectral profiles suggest that a considerable overlay of the ionic states occurs for both molecules. Under these circumstances of near degeneracy of two or more ionic states, mutual annihilation of vibrational fine structure occurs for all except the strongest vibrational states; the PES just reflects the resultants rather than full spectra. Theoretical determination of the adiabatic ionization energies (AlEs) proved a challenge; the most successful method was second order Moller-Plesset perturbation theory (MP2). These calculations suggest that the lowest PES bands for both isomers contain ionization both from lone pair sigma-orbitals ((2)A') on the N-atoms (LPN) and pi-orbitals ((2)A ''). The lowest experimental AIEs are as follows: 1-MeTet is 10.315 eV assigned to 1 2 A', while 2-MeTet is 10.543 eV assigned to 1(2)A ''. Franck-Condon analysis shows that the lowest ionization energy regions of both spectra are dominated by IE from the LPN (2)A' manifold, even though the (2)A '' states have a higher absolute intensity. In this example, we have utilized a VUV Rydberg state to assist simplification of the PES; more frequently, the PES assignment is simpler and assists the location of Rydberg states in the VUV. The very slow spectral onset for 2-MeTet demonstrates the importance of vertical ionization energy calculations since maxima are more readily measured than slow onsets. These were performed at the equilibrium structure of the X(1)A' state, using both multi-reference multiroot configuration interaction and the ionization potential variant of the equations-of-motion coupled cluster method, with single and double excitations (EOMIP-CCSD). This enabled the principal ionization bands to be identified over a wider range of energy. Attempts to study the higher ionic states by EOMIP-CCSD showed that several states of each symmetry are close to degenerate for 1-MeTet, in particular. A multi-configuration self-consistent field study confirmed the small separation of ionic states, but state switching during the optimization process largely disabled this method. Published by AIP Publishing.",
keywords = "MOLECULAR-ORBITAL CALCULATIONS, EXCITED-STATE PROPERTIES, COUPLED-CLUSTER METHOD, FOCK WAVE-FUNCTIONS, N-15 NMR, SPECTROSCOPY, AZOLES, TAUTOMERISM, TETRAZOLES",
author = "Palmer, {Michael H.} and Marcello Coreno and {de Simone}, Monica and Cesare Grazioli and Hoffmann, {Soren Vronning} and Jones, {Nykola C.} and Peterson, {Kirk A.} and Aitken, {R. Alan} and Cecile Rouxel",
year = "2018",
month = jul,
day = "21",
doi = "10.1063/1.5041249",
language = "English",
volume = "149",
journal = "Journal of Chemical Physics",
issn = "0021-9606",
publisher = "AMER INST PHYSICS",
number = "3",

}

RIS

TY - JOUR

T1 - The photoelectron spectra of the isomeric 1-and 2-methyltetrazoles; their equilibrium structures and vibrational analysis by ab initio calculations

AU - Palmer, Michael H.

AU - Coreno, Marcello

AU - de Simone, Monica

AU - Grazioli, Cesare

AU - Hoffmann, Soren Vronning

AU - Jones, Nykola C.

AU - Peterson, Kirk A.

AU - Aitken, R. Alan

AU - Rouxel, Cecile

PY - 2018/7/21

Y1 - 2018/7/21

N2 - New synchrotron based studies of the photoelectron ionization spectra (PES) for the isomeric 1- and 2-methyltetrazoles (1- and 2-MeTet) show markedly higher resolution than previous reports. The unusual spectral profiles suggest that a considerable overlay of the ionic states occurs for both molecules. Under these circumstances of near degeneracy of two or more ionic states, mutual annihilation of vibrational fine structure occurs for all except the strongest vibrational states; the PES just reflects the resultants rather than full spectra. Theoretical determination of the adiabatic ionization energies (AlEs) proved a challenge; the most successful method was second order Moller-Plesset perturbation theory (MP2). These calculations suggest that the lowest PES bands for both isomers contain ionization both from lone pair sigma-orbitals ((2)A') on the N-atoms (LPN) and pi-orbitals ((2)A ''). The lowest experimental AIEs are as follows: 1-MeTet is 10.315 eV assigned to 1 2 A', while 2-MeTet is 10.543 eV assigned to 1(2)A ''. Franck-Condon analysis shows that the lowest ionization energy regions of both spectra are dominated by IE from the LPN (2)A' manifold, even though the (2)A '' states have a higher absolute intensity. In this example, we have utilized a VUV Rydberg state to assist simplification of the PES; more frequently, the PES assignment is simpler and assists the location of Rydberg states in the VUV. The very slow spectral onset for 2-MeTet demonstrates the importance of vertical ionization energy calculations since maxima are more readily measured than slow onsets. These were performed at the equilibrium structure of the X(1)A' state, using both multi-reference multiroot configuration interaction and the ionization potential variant of the equations-of-motion coupled cluster method, with single and double excitations (EOMIP-CCSD). This enabled the principal ionization bands to be identified over a wider range of energy. Attempts to study the higher ionic states by EOMIP-CCSD showed that several states of each symmetry are close to degenerate for 1-MeTet, in particular. A multi-configuration self-consistent field study confirmed the small separation of ionic states, but state switching during the optimization process largely disabled this method. Published by AIP Publishing.

AB - New synchrotron based studies of the photoelectron ionization spectra (PES) for the isomeric 1- and 2-methyltetrazoles (1- and 2-MeTet) show markedly higher resolution than previous reports. The unusual spectral profiles suggest that a considerable overlay of the ionic states occurs for both molecules. Under these circumstances of near degeneracy of two or more ionic states, mutual annihilation of vibrational fine structure occurs for all except the strongest vibrational states; the PES just reflects the resultants rather than full spectra. Theoretical determination of the adiabatic ionization energies (AlEs) proved a challenge; the most successful method was second order Moller-Plesset perturbation theory (MP2). These calculations suggest that the lowest PES bands for both isomers contain ionization both from lone pair sigma-orbitals ((2)A') on the N-atoms (LPN) and pi-orbitals ((2)A ''). The lowest experimental AIEs are as follows: 1-MeTet is 10.315 eV assigned to 1 2 A', while 2-MeTet is 10.543 eV assigned to 1(2)A ''. Franck-Condon analysis shows that the lowest ionization energy regions of both spectra are dominated by IE from the LPN (2)A' manifold, even though the (2)A '' states have a higher absolute intensity. In this example, we have utilized a VUV Rydberg state to assist simplification of the PES; more frequently, the PES assignment is simpler and assists the location of Rydberg states in the VUV. The very slow spectral onset for 2-MeTet demonstrates the importance of vertical ionization energy calculations since maxima are more readily measured than slow onsets. These were performed at the equilibrium structure of the X(1)A' state, using both multi-reference multiroot configuration interaction and the ionization potential variant of the equations-of-motion coupled cluster method, with single and double excitations (EOMIP-CCSD). This enabled the principal ionization bands to be identified over a wider range of energy. Attempts to study the higher ionic states by EOMIP-CCSD showed that several states of each symmetry are close to degenerate for 1-MeTet, in particular. A multi-configuration self-consistent field study confirmed the small separation of ionic states, but state switching during the optimization process largely disabled this method. Published by AIP Publishing.

KW - MOLECULAR-ORBITAL CALCULATIONS

KW - EXCITED-STATE PROPERTIES

KW - COUPLED-CLUSTER METHOD

KW - FOCK WAVE-FUNCTIONS

KW - N-15 NMR

KW - SPECTROSCOPY

KW - AZOLES

KW - TAUTOMERISM

KW - TETRAZOLES

U2 - 10.1063/1.5041249

DO - 10.1063/1.5041249

M3 - Journal article

C2 - 30037262

VL - 149

JO - Journal of Chemical Physics

JF - Journal of Chemical Physics

SN - 0021-9606

IS - 3

M1 - 034305

ER -