Excited state hydrogen transfer dynamics in substituted phenols and their complexes with ammonia: π π * -π σ*energy gap propensity and ortho-substitution effect
Lifetimes of the first electronic excited state (S1) of fluorine and methyl (o-, m-, and p-) substituted phenols and their complexes with one ammonia molecule have been measured for the 00 transition and for the intermolecular stretching σ1 levels in complexes using picosecond pump-probe spectroscop...
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2010
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00219606_v133_n12_p_Pino http://hdl.handle.net/20.500.12110/paper_00219606_v133_n12_p_Pino |
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paper:paper_00219606_v133_n12_p_Pino2023-06-08T14:44:16Z Excited state hydrogen transfer dynamics in substituted phenols and their complexes with ammonia: π π * -π σ*energy gap propensity and ortho-substitution effect Ammonia complexes Ammonia molecules Basis sets C-F bonds Conical intersection Electronic excited state Good correlations Hydrogen transfer Intermolecular stretching Internal conversions Optimized geometries Ortho-substitution Out-of-plane distortions Picoseconds Pump-probe spectroscopy Quantum chemical calculations State concerns Substituted phenol Vibronic coupling Ammonia Diamond films Energy gap Fluorine Ground state Hydrogen Organic polymers Phenols Pumps Quantum chemistry Quantum theory Solids Excited states Lifetimes of the first electronic excited state (S1) of fluorine and methyl (o-, m-, and p-) substituted phenols and their complexes with one ammonia molecule have been measured for the 00 transition and for the intermolecular stretching σ1 levels in complexes using picosecond pump-probe spectroscopy. Excitation energies to the S1 (π π *) and S2 (π σ*) states are obtained by quantum chemical calculations at the MP2 and CC2 level using the aug-cc-pVDZ basis set for the ground-state and the S1 optimized geometries. The observed lifetimes and the energy gaps between the π π * and π σ* states show a good correlation, the lifetime being shorter for a smaller energy gap. This propensity suggests that the major dynamics in the excited state concerns an excited state hydrogen detachment or transfer (ESHD/T) promoted directly by a S1 / S2 conical intersection, rather than via internal conversion to the ground-state. A specific shortening of lifetime is found in the o-fluorophenol-ammonia complex and explained in terms of the vibronic coupling between the π π * and π σ* states occurring through the out-of-plane distortion of the C-F bond. © 2010 American Institute of Physics. 2010 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00219606_v133_n12_p_Pino http://hdl.handle.net/20.500.12110/paper_00219606_v133_n12_p_Pino |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Ammonia complexes Ammonia molecules Basis sets C-F bonds Conical intersection Electronic excited state Good correlations Hydrogen transfer Intermolecular stretching Internal conversions Optimized geometries Ortho-substitution Out-of-plane distortions Picoseconds Pump-probe spectroscopy Quantum chemical calculations State concerns Substituted phenol Vibronic coupling Ammonia Diamond films Energy gap Fluorine Ground state Hydrogen Organic polymers Phenols Pumps Quantum chemistry Quantum theory Solids Excited states |
| spellingShingle |
Ammonia complexes Ammonia molecules Basis sets C-F bonds Conical intersection Electronic excited state Good correlations Hydrogen transfer Intermolecular stretching Internal conversions Optimized geometries Ortho-substitution Out-of-plane distortions Picoseconds Pump-probe spectroscopy Quantum chemical calculations State concerns Substituted phenol Vibronic coupling Ammonia Diamond films Energy gap Fluorine Ground state Hydrogen Organic polymers Phenols Pumps Quantum chemistry Quantum theory Solids Excited states Excited state hydrogen transfer dynamics in substituted phenols and their complexes with ammonia: π π * -π σ*energy gap propensity and ortho-substitution effect |
| topic_facet |
Ammonia complexes Ammonia molecules Basis sets C-F bonds Conical intersection Electronic excited state Good correlations Hydrogen transfer Intermolecular stretching Internal conversions Optimized geometries Ortho-substitution Out-of-plane distortions Picoseconds Pump-probe spectroscopy Quantum chemical calculations State concerns Substituted phenol Vibronic coupling Ammonia Diamond films Energy gap Fluorine Ground state Hydrogen Organic polymers Phenols Pumps Quantum chemistry Quantum theory Solids Excited states |
| description |
Lifetimes of the first electronic excited state (S1) of fluorine and methyl (o-, m-, and p-) substituted phenols and their complexes with one ammonia molecule have been measured for the 00 transition and for the intermolecular stretching σ1 levels in complexes using picosecond pump-probe spectroscopy. Excitation energies to the S1 (π π *) and S2 (π σ*) states are obtained by quantum chemical calculations at the MP2 and CC2 level using the aug-cc-pVDZ basis set for the ground-state and the S1 optimized geometries. The observed lifetimes and the energy gaps between the π π * and π σ* states show a good correlation, the lifetime being shorter for a smaller energy gap. This propensity suggests that the major dynamics in the excited state concerns an excited state hydrogen detachment or transfer (ESHD/T) promoted directly by a S1 / S2 conical intersection, rather than via internal conversion to the ground-state. A specific shortening of lifetime is found in the o-fluorophenol-ammonia complex and explained in terms of the vibronic coupling between the π π * and π σ* states occurring through the out-of-plane distortion of the C-F bond. © 2010 American Institute of Physics. |
| title |
Excited state hydrogen transfer dynamics in substituted phenols and their complexes with ammonia: π π * -π σ*energy gap propensity and ortho-substitution effect |
| title_short |
Excited state hydrogen transfer dynamics in substituted phenols and their complexes with ammonia: π π * -π σ*energy gap propensity and ortho-substitution effect |
| title_full |
Excited state hydrogen transfer dynamics in substituted phenols and their complexes with ammonia: π π * -π σ*energy gap propensity and ortho-substitution effect |
| title_fullStr |
Excited state hydrogen transfer dynamics in substituted phenols and their complexes with ammonia: π π * -π σ*energy gap propensity and ortho-substitution effect |
| title_full_unstemmed |
Excited state hydrogen transfer dynamics in substituted phenols and their complexes with ammonia: π π * -π σ*energy gap propensity and ortho-substitution effect |
| title_sort |
excited state hydrogen transfer dynamics in substituted phenols and their complexes with ammonia: π π * -π σ*energy gap propensity and ortho-substitution effect |
| publishDate |
2010 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00219606_v133_n12_p_Pino http://hdl.handle.net/20.500.12110/paper_00219606_v133_n12_p_Pino |
| _version_ |
1768544488169406464 |