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Title: Electron-ion-ion triple-coincidence spectroscopic study of site-specific fragmentation caused by Si:2p core-level photoionization of F{sub 3}SiCH{sub 2}CH{sub 2}Si(CH{sub 3}){sub 3} vapor

Abstract

Site-specific fragmentation caused by Si:2p core-level photoionization of F{sub 3}SiCH{sub 2}CH{sub 2}Si(CH{sub 3}){sub 3} vapor was studied by means of high-resolution energy-selected-electron photoion-photoion triple-coincidence spectroscopy. The ab initio molecular orbital method was used for the theoretical description. F{sub 3}SiCH{sub 2}CH{sub 2}{sup +}-Si(CH{sub 3}){sub 3}{sup +} ion pairs were produced by the 2p photoionization of the Si atoms bonded to the three methyl groups, and SiF{sup +}-containing ion pairs were produced by the 2p photoionization of the Si atoms bonded to the three F atoms.

Authors:
; ;  [1]; ; ; ; ;  [2]; ;  [3];  [4]; ; ;  [5]
  1. Department of Chemistry, Ehime University, Matsuyama 790-8577 (Japan)
  2. Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577 (Japan)
  3. JASRI, 1-1-1 Kouto, Sayo-cho, Sayo-gun 679-5198 (Japan)
  4. AIST, Tsukuba 305-8568 (Japan)
  5. Department of Chemistry, Hiroshima University, Higashi-Hiroshima 739-8526 (Japan)
Publication Date:
OSTI Identifier:
20982050
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. A; Journal Volume: 75; Journal Issue: 2; Other Information: DOI: 10.1103/PhysRevA.75.020502; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; ATOMS; COINCIDENCE SPECTROMETRY; DISSOCIATION; ELECTRONS; FRAGMENTATION; ION PAIRS; IONS; MOLECULAR IONS; MOLECULAR ORBITAL METHOD; ORGANIC COMPOUNDS; PHOTOELECTRON SPECTROSCOPY; PHOTOIONIZATION; PHOTOLYSIS; PHOTON-MOLECULE COLLISIONS; RESOLUTION; SILICON FLUORIDES; SILICON IONS; VAPORS

Citation Formats

Nagaoka, S., Hino, M., Takemoto, M., Pruemper, G., Fukuzawa, H., Liu, X.-J., Lischke, T., Ueda, K., Tamenori, Y., Harries, J., Suzuki, I. H., Takahashi, O., Okada, K., and Tabayashi, K.. Electron-ion-ion triple-coincidence spectroscopic study of site-specific fragmentation caused by Si:2p core-level photoionization of F{sub 3}SiCH{sub 2}CH{sub 2}Si(CH{sub 3}){sub 3} vapor. United States: N. p., 2007. Web. doi:10.1103/PHYSREVA.75.020502.
Nagaoka, S., Hino, M., Takemoto, M., Pruemper, G., Fukuzawa, H., Liu, X.-J., Lischke, T., Ueda, K., Tamenori, Y., Harries, J., Suzuki, I. H., Takahashi, O., Okada, K., & Tabayashi, K.. Electron-ion-ion triple-coincidence spectroscopic study of site-specific fragmentation caused by Si:2p core-level photoionization of F{sub 3}SiCH{sub 2}CH{sub 2}Si(CH{sub 3}){sub 3} vapor. United States. doi:10.1103/PHYSREVA.75.020502.
Nagaoka, S., Hino, M., Takemoto, M., Pruemper, G., Fukuzawa, H., Liu, X.-J., Lischke, T., Ueda, K., Tamenori, Y., Harries, J., Suzuki, I. H., Takahashi, O., Okada, K., and Tabayashi, K.. Thu . "Electron-ion-ion triple-coincidence spectroscopic study of site-specific fragmentation caused by Si:2p core-level photoionization of F{sub 3}SiCH{sub 2}CH{sub 2}Si(CH{sub 3}){sub 3} vapor". United States. doi:10.1103/PHYSREVA.75.020502.
@article{osti_20982050,
title = {Electron-ion-ion triple-coincidence spectroscopic study of site-specific fragmentation caused by Si:2p core-level photoionization of F{sub 3}SiCH{sub 2}CH{sub 2}Si(CH{sub 3}){sub 3} vapor},
author = {Nagaoka, S. and Hino, M. and Takemoto, M. and Pruemper, G. and Fukuzawa, H. and Liu, X.-J. and Lischke, T. and Ueda, K. and Tamenori, Y. and Harries, J. and Suzuki, I. H. and Takahashi, O. and Okada, K. and Tabayashi, K.},
abstractNote = {Site-specific fragmentation caused by Si:2p core-level photoionization of F{sub 3}SiCH{sub 2}CH{sub 2}Si(CH{sub 3}){sub 3} vapor was studied by means of high-resolution energy-selected-electron photoion-photoion triple-coincidence spectroscopy. The ab initio molecular orbital method was used for the theoretical description. F{sub 3}SiCH{sub 2}CH{sub 2}{sup +}-Si(CH{sub 3}){sub 3}{sup +} ion pairs were produced by the 2p photoionization of the Si atoms bonded to the three methyl groups, and SiF{sup +}-containing ion pairs were produced by the 2p photoionization of the Si atoms bonded to the three F atoms.},
doi = {10.1103/PHYSREVA.75.020502},
journal = {Physical Review. A},
number = 2,
volume = 75,
place = {United States},
year = {Thu Feb 15 00:00:00 EST 2007},
month = {Thu Feb 15 00:00:00 EST 2007}
}
  • Rate constants and product distributions have been determined for gas-phase reactions of ground-state Si/sup +/(/sup 2/P) ions with ammonia and the amines (CH/sub 3/)/sub x/NH/sub 3-x/ (x = 1-3) at 296 +- 2 K with the selected-ion flow tube technique. All reactions were observed to be fast and can be understood in terms of Si/sup +/ insertion into N-H and C-N bonds to form ions of the type SiNR/sub 1/R/sub 2//sup +/ (r/sub 1/, R/sub 2/ = H, CH/sub 3/) proceeding in competition (in the case of the amines) with hydride ion transfer to form immonium ions of the typemore » CH/sub 2/NR/sub 1/R/sub 2//sup +/ (R/sub 1/, R/sub 2/ = H, CH/sub 3/). C-N bond insertion appears more efficient than N-H bond insertion. The contribution of hydride ion transfer increases with increasing stability of the immonium ion. The latter reaction leads directly to SiH as a neutral product. Other minor reaction channels were seen which lead directly or indirectly to SiCH and SiCH/sub 3/. Rapid secondary proton transfer reactions were observed for SiNH/sub 2//sup +/ and SiNHCH/sub 3//sup +/ to produce gas-phase SiNH and SiNCH/sub 3/ molecules. With methylamine SiNH/sub 2//sup +/ also appears to produce H/sub 2/SiNH/sub 2//sup +/ which may deprotonate to form the simplest silanimine, H/sub 2/SiNH, or aminosilylene, HSiNH/sub 2/. Reactions of this type are of interest in molecular synthesis and here are proposed to contribute to the formation of SiH, SiCH, SiNH, SiCH/sub 3/, and H/sub 2/SiNH or HSiNH/sub 2/ in partially ionized interstellar gas clouds containing silicon, ammonia, and methylamines.« less
  • We have carried out a coincidence experiment between energy-resolved resonant Auger electrons and mass-resolved ions on CH{sub 3}F molecules following F 1s and C 1s excitation to the lowest unoccupied C-F antibonding molecular orbital {sigma}{sub CF}{sup .} We found a strong enhancement of the F{sup +} or CH{sup +} ion production in coincidence with the F KVV and C KVV spectator Auger electrons, respectively, in the wide binding energy range of 28-36 eV. This site-selective ion production is interpreted as a consequence of the resonant Auger emission taking place in the transient region where the C-F elongation caused by themore » core excitation transforms the molecular valence orbitals gradually into nonoverlapping valence orbitals of each fragment.« less
  • The reaction of Re{sub 2}O{sub 7} with XeF{sub 6} in anhydrous HF provides a convenient route to high-purity ReO{sub 2}F{sub 3}. The fluoride acceptor and Lewis base properties of ReO{sub 2}F{sub 3} have been investigated leading to the formation of [M][ReO{sub 2}F{sub 4}] [M = Li, Na, Cs, N(CH{sub 3}){sub 4}], [K][Re{sub 2}O{sub 4}F{sub 7}], [K][Re{sub 2}O{sub 4}F{sub 7}]{center_dot}2ReO{sub 2}F{sub 3}, [Cs][Re{sub 3}O{sub 6}F{sub 10}], and ReO{sub 2}F{sub 3}(CH{sub 3}CN). The ReO{sub 2}F{sub 4}{sup {minus}}, Re{sub 2}O{sub 4}F{sub 7}{sup {minus}}, and Re{sub 3}O{sub 6}F{sub 10{sup {minus}} anions and the ReO{sub 2}F{sub 3}(CH{sub 3}CN) adduct have been characterized in the solidmore » state by Raman spectroscopy, and the structures [Li][ReO{sub 2}F{sub 4}], [K][Re{sub 2}O{sub 4}F{sub 7}], [K][Re{sub 2}O{sub 4}F{sub 7}]{center_dot}2ReO{sub 2}F{approximately}3}, [Cs][Re{sub 3}O{sub 6}F{sub 10}], and ReO{sub 3}F(CH{sub 3}CN){sub 2}{center_dot}CH{sub 3}CN have been determined by X-ray crystallography. The structure of ReO{sub 2}F{sub 4}{sup {minus}} consists of a cis-dioxo arrangement of Re-O double bonds in which the Re-F bonds trans to the oxygen atoms are significantly lengthened as a result of the trans influence of the oxygens. The Re{sub 2}O{sub 4}F{sub 7}{sup {minus}} and Re{sub 3}O{sub 6}F{sub 10}{sup {minus}} anions and polymeric ReO{sub 2}F{sub 3} are open chains containing fluorine-bridged ReO{sub 2}F{sub 4} units in which each pair of Re-O bonds are cis to each other and the fluorine bridges are trans to oxygens. The trans influence of the oxygens is manifested by elongated terminal Re-F bonds trans to Re-O bonds as in ReO{sub 2}F{sub 4}{sup {minus}} and by the occurrence of both fluorine bridges trans to Re-O bonds. Fluorine-19 NMR spectra show that ReO{sub 2}F{sub 4}{sup {minus}}, Re{sub 2}O{sub 4}F{sub 7}{sup {minus}}, and ReO{sub 2}F{sub 3}(CH{sub 3}CN) have cis-dioxo arrangements in CH{sub 3}CN solution. Density functional theory calculations at the local and nonlocal levels confirm that the cis-dioxo isomers of ReO{sub 2}F{sub 4}{sup {minus}} and ReO{sub 2}F{sub 3}(CH{sub 3}CN), where CH{sub 3}CN is bonded trans to an oxygen, are the energy-minimized structures. The adduct ReO{sub 3}F(CH{sub 3}CN){sub 2}{center_dot}CH{sub 3}CN was obtained by hydrolysis of ReO{sub 2}F{sub 3}(CH{sub 3}CN), and was shown by X-ray crystallography to have a facial arrangement of oxygen atoms on rhenium.« less
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  • We have studied the electronic decay of an oxygen 1s core hole in N/sub 2/O and the subsequent fragmentation into ions. Coincidence studies between the energy resolved Auger electrons and the ions reveal the individual decay channels for the various doubly charged ionic configurations populated in the Auger decay of the core hole. The site specificity in these events is not absolutely confined to breaking only the O--NN bond, even though the excitation of a core hole at the oxygen site in the initial absorption event is localized. This localization is to some extent preserved in the Auger decay, whichmore » favors the participation of valence electrons having wave functions with a large overlap at the site of the initial oxygen core hole. However some of these electrons are also crucial in forming the ON--N bond or the bonding structure of the molecule as a whole, such that removal of these electrons in the Auger decay results in the total destruction of the molecular bond.« less