The Threshold Photoelectron Spectrum of Fulvenone: A Reactive Ketene Derivative in Lignin Valorization.
Chemphyschem
; 21(19): 2217-2222, 2020 10 02.
Article
em En
| MEDLINE
| ID: mdl-32628323
ABSTRACT
Unveiling reaction mechanisms by isomer-selective detection of reactive intermediates requires advanced spectroscopic knowledge. We study the photoionization of fulvenone (c-C5 H4 =C=O), a reactive ketene species relevant in catalytic pyrolysis of lignin, which was generated by pyrolysis of 2-methoxy acetophenone. The high-resolution threshold photoelectron spectrum (TPES) with vacuum ultraviolet synchrotron radiation revealed well-resolved vibrational transitions, assigned to ring deformation modes of the cyclopentadiene moiety. The adiabatic ionization energy was determined to be 8.25±0.01â
eV and is assigned to the XË+2 A2 â XË1 A1 transition. A broad and featureless band arising at 9â
eV is associated with the AË+2 B1 â XË1 A1 excitation. A conical intersection is responsible for the ultrafast relaxation of the fulvenone cation from the AË+ into the XË+ state resulting in a featureless and lifetime broadened band. These insights will increase the detection capabilities for fulvenone and thereby help to elucidate reaction mechanisms in lignin catalytic pyrolysis.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Chemphyschem
Assunto da revista:
BIOFISICA
/
QUIMICA
Ano de publicação:
2020
Tipo de documento:
Article
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