Photophysical studies of formic acid in the VUV. Absorption spectrum in the 6–22 eV region

Leach, Sydney; Schwell, Martin; Dulieu, F.; Chotin, Jean-Louis; Jochims, H.‐W.; Baumgärtel, H.

doi:10.1039/b205729h

Cited by 33 publications

(81 citation statements)

References 42 publications

(137 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The recorded absolute σ a and η spectra are shown in Figure a,b, respectively, in comparison with previous results of Leach et al and Schwell et al Numerical values in units of Mb (1 × 10 –18 cm 2 ) for some selected energies are listed in Table S1 of the Supporting Information. As can be observed in Figure a, our σ a values are systematically above the data of Leach et al The maximum cross section reported by these authors is 46.7 Mb in the 17–22 eV region, around 13% lower than the maximum value of 53.3 Mb at 17.7 eV found in the present work.…”

Section: Resultssupporting

confidence: 80%

“…Each dipole-allowed ionization channel ( a ′ → ka ′, ka ″ and a ″ → ka ′, ka ″) is calculated separately, and the partial cross sections are summed in both L and V forms. The experimental ionization energies considered in calculation to generate photoelectrons from the corresponding 10 a ′, 2 a ″, 9 a ′, 1 a ″, 8 a ′, and 7 a ′ molecular orbitals were 11.33, 12.38, 14.81, 15.35, 16.97, and 17.28 eV, respectively. , The wave functions and interaction potentials, as well as the related matrices, were all single-center-expanded around the center of mass of the molecule in terms of the symmetry-adapted functions . Our partial-wave expansion for the molecular orbitals and for the scattering wave functions included up to l max = 20.…”

Section: Computational Detailsmentioning

confidence: 99%

See 1 more Smart Citation

Cross Sections and Asymmetry Parameters for Formic Acid in the Vacuum-Ultraviolet Energy Range

et al. 2020

View full text Add to dashboard Cite

We present an experimental and theoretical investigation of the photon interaction with formic acid in the vacuumultraviolet energy range. The absolute absorption cross sections and ionization efficiencies were measured in the 11.2−21.4 and 13.5−21.4 eV ranges, respectively, using a double-ion chamber technique. Photoionization and neutral-decay cross sections were derived from these results. From the present ionization cross sections and previously reported ionic dissociative branching ratios, the partial cross sections for dissociating processes were obtained. Theoretically, the photoionization cross sections and the asymmetry parameters of the photoelectron angular distributions for ionization out of the six outermost valence orbitals (10a′, 2a″, 9a′, 1a″, 8a′, and 7a′) were obtained in the energy range from near-threshold to 35 eV. For that, the Padéapproximant technique along with the single-center partial-wave expansion method was applied to solve the Lippmann-Schwinger equation in the static-exchangepolarization level of approximation. This is the first theoretical investigation concerning the determination of the asymmetry parameters and photoionization cross sections of formic acid in the vacuum-ultraviolet energy range. Comparison is made between our results and the previous ones.

show abstract

Section: Resultssupporting

confidence: 80%

Section: Computational Detailsmentioning

confidence: 99%

Cross Sections and Asymmetry Parameters for Formic Acid in the Vacuum-Ultraviolet Energy Range

et al. 2020

View full text Add to dashboard Cite

show abstract

“…The π * orbital is mostly located at the C=O group [22,24]. The 3sa has been identified as an antibonding orbital in OH [23,25]. While the O 1s TPIY only contains broad resonances, C 1s TPIY shows a prominent set of Rydberg resonances above the π * and 3sa peaks, leading up to the ionization potential (IP) [20].…”

Section: Methodsmentioning

confidence: 99%

Negative- and positive-ion fragmentation of core-excited formic-acid molecules studied with three- and four-ion coincidence spectroscopy

et al. 2017

View full text Add to dashboard Cite

The negative-ion fragmentation of formic acid (HCOOH) is studied with negative-and positive-ion coincidence spectroscopy. We report four-body ionic fragmentation where up to three positive ions are collected in coincidence with one negative ion. We report yields for 21 three-body channels and five four-body channels. More than 80% of all negative-ion fragmentation involves production of O − , and it is dominated by complete dissociation of all molecular bonds. Negative-ion creation is most abundant at high-Rydberg resonances and just above the molecule's core-ionization potentials. The existence of four-body fragmentation channels evidences a strong charge redistribution in the molecule.

show abstract

“…Contrary to formic acid monomer's electronic spectrum, which has been intensively investigated, [21][22][23][24][25][26][27][28][29][30][31][32][33][34] studies on the excited states of formic acid dimer are scarce. To the best of our knowledge only three experimental works 22,35,36 are available in the literature reporting on the electronic absorption spectrum of formic acid dimer, the latest published in 1992.…”

Section: Introductionmentioning

confidence: 99%

Hydrogen bonding in electronically excited states: a comparison between formic acid dimer and its mono-substituted thioderivatives

Cimas

Mó

Yáñez

et al. 2010

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

A multi-state complete active space second order perturbation theory (MS-CASPT2) study on the valence singlet electronic excited states of formic acid dimer is presented. The electronic spectrum of this dihydrogen bonded system is dominated by nπ* and ππ* intramonomer and charge transfer excitations and consists of a very intense ππ* transition at 8.25 eV and three weaker nπ*(2×) and ππ*(1×) electronic excitations at 6.21 eV, 9.13 eV, and 9.93 eV, respectively. The characteristic nπ*-nπ*-ππ*-ππ*… pattern found in the formic acid dimer electronic spectrum is altered when a sulfur atom is introduced in the molecule. Furthermore, carbonyl-by-thiocarbonyl or hydroxyl-by-thiohydroxyl substitution is predicted to strongly affect the intensity of the above electronic transitions. The effect of oxygen-by-sulfur substitution on the geometry of the first excited state (S(1)) has been investigated at the CC2 and CASSCF levels of theory. Although the two methods qualitatively predict the same geometrical changes upon nπ* excitation, the geometries of the S(1) state are found to differ considerably between the two levels.

show abstract

Photophysical studies of formic acid in the VUV. Absorption spectrum in the 6–22 eV region

Cited by 33 publications

References 42 publications

Cross Sections and Asymmetry Parameters for Formic Acid in the Vacuum-Ultraviolet Energy Range

Cross Sections and Asymmetry Parameters for Formic Acid in the Vacuum-Ultraviolet Energy Range

Negative- and positive-ion fragmentation of core-excited formic-acid molecules studied with three- and four-ion coincidence spectroscopy

Hydrogen bonding in electronically excited states: a comparison between formic acid dimer and its mono-substituted thioderivatives

Contact Info

Product

Resources

About