التفاصيل البيبلوغرافية
| العنوان: |
Electronically excited states of formic acid investigated by theoretical and experimental methods |
| المؤلفون: |
Randi, P. A. S., Pastega, D. F., Bettega, M. H. F., Jones, N. C., Hoffmann, S. V., Eden, S., Souza Barbosa, A., Limão-Vieira, P. |
| المساهمون: |
DF – Departamento de Física, CeFITec – Centro de Física e Investigação Tecnológica, RUN |
| سنة النشر: |
2023 |
| وصف مادي: |
12 |
| مصطلحات موضوعية: |
Cross-sections, Formic acid, ISM molecules, Spectroscopy, Theoretical calculations, Ultraviolet, Analytical Chemistry, Atomic and Molecular Physics, and Optics, Instrumentation |
| الوصف: |
PASR acknowledges support from the Brazilian agency Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES). ASB and MHFB acknowledge support from the Brazilian agency Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq). PASR, ASB and MHFB also acknowledge Prof. Carlos de Carvalho for computational support at LFTC-DFis-UFPR and at LCPAD-UFPR. The authors wish to acknowledge the beam time at the ISA synchrotron, Aarhus University, Denmark. PLV acknowledges the Portuguese National Funding Agency (FCT), as well as his visiting professor position at Federal University of Paraná, Curitiba, Brazil. This contribution is also based upon work from the COST Action CA18212-Molecular Dynamics in the GAS phase (MD-GAS), supported by COST (European Cooperation in Science and Technology). Publisher Copyright: © 2022 The Author(s) |
| الوصف (مترجم): |
Absolute cross-section values are reported from high-resolution vacuum ultraviolet (VUV) photoabsorption measurements of gas-phase formic acid (HCOOH) in the photon energy range 4.7–10.8 eV (265–115 nm), together with quantum chemical calculations to provide vertical energies and oscillator strengths. The combination of experimental and theoretical methods has allowed a comprehensive assignment of the electronic transitions. The VUV spectrum reveals various vibronic features not previously reported in the literature, notably associated with (3pa′←10a′), (3p′a′←10a′), (3sa′←2a″) and (3pa′←2a″) Rydberg transitions. The assignment of vibrational features in the absorption bands reveal that the C=O stretching, v3′a′, the H′–O–C′ deformation, v5′a′, the C–O stretching, v6′a′, and the O=C–O′ deformation, v7′a′ modes are mainly active. The measured absolute photoabsorption cross sections have also been used to estimate the photolysis lifetime of HCOOH in the upper stratosphere (30–50 km), showing that solar photolysis is an important sink at altitudes above 30 km but not in the troposphere. Potential energy curves for the lowest-lying electronic excited states, as a function of the C=O coordinate, are obtained employing time dependent density functional theory (TD-DFT). These calculations have shown the relevance of internal conversion from Rydberg to valence character governing the nuclear dynamics, yielding clear evidence of the rather complex multidimensional nature of the potential energy surfaces involved. |
| نوع الوثيقة: |
journal article |
| وصف الملف: |
application/pdf |
| اللغة: |
English |
| العلاقة: |
1386-1425; PURE: 61381953 |
| DOI: |
10.1016/j.saa.2022.122237 |
| الإتاحة: |
http://hdl.handle.net/10362/153140Test |
| حقوق: |
open access |
| رقم الانضمام: |
rcaap.com.unl.run.unl.pt.10362.153140 |
| قاعدة البيانات: |
RCAAP |
