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Le Guen K, Miron C, Céolin D, Guillemin R, Leclercq N, Simon M, Morin P, Mocellin A, Björneholm O, Naves de Brito A, Sorensen SL. H2S ultrafast dissociation probed by energy-selected resonant Auger electron–ion coincidence measurements. J Chem Phys 2007; 127:114315. [PMID: 17887845 DOI: 10.1063/1.2776265] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We have studied the ultrafast dissociation of the H2S molecule upon S 2p3/2-->6a1 inner-shell excitation by combining high-resolution resonant Auger spectroscopy and energy-selected Auger electron-ion coincidence measurements. Auger final states have been correlated to the different fragmentation pathways (S+, HS+, and H2S+ ions). As an original result, we evidence a three-step mechanism to describe the resonant production of S+: the Auger recombination in the HS* fragment is followed for the A 3Pi and c 1Pi states by the S++H fragmentation mechanism.
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Affiliation(s)
- K Le Guen
- Laboratoire de Chimie Physique-Matière et Rayonnement (LCPMR), UMR 7614, Université Pierre et Marie Curie-Paris 6, 11 Rue Pierre et Marie Curie, F-75231 Paris Cedex 05, France.
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Vall-Llosera G, Melero García E, Kivimäki A, Rachlew E, Coreno M, de Simone M, Richter R, Prince KC. Fluorescence emission from photo-fragments after resonant S 2p excitations in H2S. Phys Chem Chem Phys 2007; 9:389-95. [PMID: 17199155 DOI: 10.1039/b610199b] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Visible-UV fluorescence emission of gas-phase hydrogen sulfide, H(2)S, has been studied at the S 2p edge with synchrotron radiation excitation. Dispersed fluorescence measurements in the wavelength range 300-900 nm were taken at several photon energies corresponding to the excitations of the S 2p electrons to the unoccupied molecular and Rydberg orbitals. The spectra reveal fluorescence from the H, S, S(+), HS and HS(+) photo-fragments. H is found to be the strongest emitter at Rydberg excitations, while the emission from S(+) is dominant at the molecular resonances and above the S 2p ionization thresholds. The intensities of hydrogen Lyman-alpha (122 nm), Balmer-alpha (656 nm), Balmer-beta (486 nm) transitions as well as the visible-UV total fluorescence yield (300-900 nm) and the total ion yield were measured by scanning the photon energy in small steps across the S 2p edge. The different Balmer lines show some sensitivity to the specific core excitations, which is, however, not so strong as that recently observed in the water molecule [E. Melero García, A. Kivimäki, L. G. M. Pettersson, J. Alvarez Ruiz, M. Coreno, M. de Simone, R. Richter and K. C. Prince, Phys. Rev. Lett., 2006, 96, 063003].
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Affiliation(s)
- G Vall-Llosera
- Royal Institute of Technology, Department of Physics, AlbaNova University Center, 10691 Stockholm, Sweden.
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Meyer M, O'keeffe P, Plenge J, Flesch R, Rühl E. Radiative relaxation and fragmentation dynamics of S 2p-excited hydrogen sulfide. J Chem Phys 2006; 125:214306. [PMID: 17166020 DOI: 10.1063/1.2400234] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Radiative relaxation of S 2p-excited hydrogen sulfide (H(2)S) is investigated by dispersed ultraviolet and visible fluorescence spectroscopies. We observe distinct changes in the fluorescence spectra as a function of excitation energy. Excitation to Rydberg states below the S 2p ionization threshold yields intense fluorescence from neutral and ionic atomic fragments (H, S(+), and S(2+)). In addition to the atomic emission, fluorescence of the molecular fragment ion HS(+) is preferably found after excitation of the S 2p electron into the unoccupied 6a(1) and 3b(2) orbitals with sigma(*) character. This is interpreted as evidence for ultrafast dissociation of the core-excited molecule prior to electronic relaxation. The rotationally resolved fluorescence spectra of the A (3)Pi-->X (3)Sigma(-) transition are analyzed in terms of the fragmentation dynamics leading to the formation of the excited molecular fragment ion, where changes in bond angle are discussed in terms of the rotational population.
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Affiliation(s)
- M Meyer
- LURE, Centre Universitaire Paris-Sud, Bâtiment 209D, F-91898 Orsay Cedex, France
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Hjelte I, Björneholm O, Carravetta V, Angeli C, Cimiraglia R, Wiesner K, Svensson S, Piancastelli MN. Constant-atomic-final-state filtering of dissociative states in the O1s→σ* core excitation in O2. J Chem Phys 2005; 123:64314. [PMID: 16122315 DOI: 10.1063/1.1995689] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The below-threshold region in core-excited O2 is very complex, consisting of a multitude of exchange-split states with mixed molecular orbital-Rydberg character. We have investigated the nature of these intermediate states by resonant Auger spectroscopy. In particular, we have obtained constant-atomic-final-state yield curves for several atomic peaks in the electron decay spectra which are stemming from ultrafast dissociation. The relative intensity of Auger decay leading to atomic final states is considered a signature of the relative weight of the sigma* character. This method allows one to "filter out" intermediate states with dissociative character. Extensive calculations have been performed by multi-reference configuration interaction at different interatomic distances in order to evaluate the potential curves of the core-excited states and propose a qualitative description of the dissociative molecular dynamics. The calculations show that the core-excited states have a relevant admixture of excitations to orbitals with Rydberg character and excitations to the sigma* orbital with different spin couplings. A diabatization of the adiabatic potential curves shows that the coupling between Rydberg and sigma* diabatic states is very different at the different crossing points and ultrafast dissociation occurs more easily on the lowest sigma* diabatic potential curve. As a consequence, the observation of atomic peaks only in the lower-energy region of the absorption curve is well justified.
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Affiliation(s)
- I Hjelte
- Physics Department, Uppsala University, Uppsala, Sweden
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Guillemin R, Stolte WC, Dang LTN, Yu SW, Lindle DW. Fragmentation dynamics of H2S following S 2p photoexcitation. J Chem Phys 2005; 122:094318. [PMID: 15836139 DOI: 10.1063/1.1860012] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The fragmentation dynamics of core-excited H(2)S has been studied by means of partial anion and cation yield measurements around the S L(2,3)-subshell ionization thresholds. All detectable ionic fragments are reported, and significant differences between partial ion yields are observed. Possible dissociation pathways are discussed by comparison to previous studies of electron spectra.
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Affiliation(s)
- R Guillemin
- Department of Chemistry, University of Nevada, Las Vegas, Nevada 89154-4003, USA
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Hjelte I, Piancastelli M, Fink R, Björneholm O, Bässler M, Feifel R, Giertz A, Wang H, Wiesner K, Ausmees A, Miron C, Sorensen S, Svensson S. Evidence for ultra-fast dissociation of molecular water from resonant Auger spectroscopy. Chem Phys Lett 2001. [DOI: 10.1016/s0009-2614(00)01434-2] [Citation(s) in RCA: 109] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Memories of excited femtoseconds: effects of core–hole localization after Auger decay in the fragmentation of ozone. Chem Phys Lett 2000. [DOI: 10.1016/s0009-2614(00)00900-3] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Lavollée M, Brems V. Kinematics of the three-body dissociation of SO23+, after sulphur 2p photoexcitation of the SO2 molecule. J Chem Phys 1999. [DOI: 10.1063/1.478059] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Fast dissociation of resonantly core excited H2S studied by vibrational and temporal analysis of the Auger spectra. ACTA ACUST UNITED AC 1997. [DOI: 10.1016/s0166-1280(96)04828-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Naves de Brito A, Svensson S, Osborne SJ, Ausmees A, Kivimäki A, Sairanen OP, Nõmmiste E, Aksela H, Aksela S, Saethre LJ. Auger decay of the molecular field split S 2p core excited states in HS radical. J Chem Phys 1997. [DOI: 10.1063/1.473035] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Competition between direct dissociation and resonant Auger decay: a quasi-classical model applied to the 2p−1 σ∗ states of HCl, DCl and Cl2. Chem Phys Lett 1996. [DOI: 10.1016/0009-2614(96)00607-0] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Gelmukhanov F, gren H. X-ray resonant scattering involving dissociative states. PHYSICAL REVIEW. A, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 1996; 54:379-393. [PMID: 9913488 DOI: 10.1103/physreva.54.379] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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de Miranda MP, Beswick JA, Parent P, Laffon C, Tourillon G, Cassuto A, Nicolas G, Gadea FX. Fine vibrational structure in core‐to‐bound spectra of polyatomic molecules. J Chem Phys 1994. [DOI: 10.1063/1.467339] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Gel'mukhanov F, gren H. Channel interference in resonance elastic x-ray scattering. PHYSICAL REVIEW. A, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 1994; 50:1129-1132. [PMID: 9911002 DOI: 10.1103/physreva.50.1129] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Hudson E, Shirley DA, Domke M, Remmers G, Kaindl G. High-resolution photoabsorption near the sulfur L2,3 thresholds: H2S and D2S. PHYSICAL REVIEW A 1994; 49:161-175. [PMID: 9910217 DOI: 10.1103/physreva.49.161] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Correia N, Wannberg B, Baltzer P, Karlsson L, Svensson S, Adam MY, Aksela H, Aksela S. Vibrationally resolved states in the HS fragment studied by means of electron-excited Auger spectroscopy. PHYSICAL REVIEW. A, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 1992; 46:6067-6070. [PMID: 9908867 DOI: 10.1103/physreva.46.6067] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Aksela H, Aksela S, Bancroft GM, Tan KH. Decay channels of core-excited H2S studied by synchrotron-radiation-excited photoelectron spectroscopy. PHYSICAL REVIEW. A, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 1992; 45:7948-7952. [PMID: 9906885 DOI: 10.1103/physreva.45.7948] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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