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Title: Oxidation of Gas-Phase Protactinium Ions, Pa+ and Pa2+: Formation and Properties of PaO22+(g), Protactinyl

Abstract

Oxidation reactions of bare and ligated, monopositive, and dipositive Pa ions in the gas phase were studied by Fourier transform ion cyclotron resonance mass spectrometry. Seven oxidants were employed, ranging from the thermodynamically robust N{sub 2}O to the relatively weak CH{sub 2}O - all oxidized Pa{sup +} to PaO{sup +} and PaO{sup +} to PaO{sub 2}{sup +}. On the basis of experimental observations, it was established that D[Pa{sup +}-O] and D[OPa{sup +}-O] {ge} 751 kJ mol{sup -1}. Estimates for D[Pa{sup +}-O], D[OPa{sup +}-O], IE[PaO], and IE[PaO{sub 2}] were also obtained. The seven oxidants reacted with Pa{sup 2+} to produce PaO{sup 2+}, indicating that D[Pa{sup 2+}-O] {ge} 751 kJ mol{sup -1}. A particularly notable finding was the oxidation of PaO{sup 2+} by N{sub 2}O to PaO{sub 2}{sup 2+}, a species, which formally comprises Pa(VI). Collision-induced dissociation of PaO{sub 2}{sup 2+} suggested the protactinyl connectivity, {l_brace}O-Pa-O{r_brace}{sup 2+}. The experimentally determined IE[PaO{sub 2}{sup +}] {approx} 16.6 eV is in agreement with self-consistent-field and configuration interaction calculations for PaO{sub 2}{sup +} and PaO{sub 2}{sup 2+}. These calculations provide insights into the electronic structures of these ions and indicate the participation of 5f orbitals in bonding and a partial '6p hole' in the case ofmore » protactinyl. It was found that PaO{sub 2}{sup 2+} catalyzes the oxidation of CO by N{sub 2}O - such O atom transport via a dipositive metal oxide ion is distinctive. It was also observed that PaO{sub 2}{sup 2+} is capable of activating H{sub 2} to form the stable PaO{sub 2}H{sup 2+} ion.« less

Authors:
 [1];  [1];  [1];  [2];  [3];  [3]
  1. Instituto Tecnologico e Nuclear, Sacavem, Portugal
  2. ORNL
  3. Ohio State University
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
1003302
DOE Contract Number:  
DE-AC05-00OR22725
Resource Type:
Journal Article
Journal Name:
Journal of Physical Chemistry A
Additional Journal Information:
Journal Volume: 110; Journal Issue: 17; Journal ID: ISSN 1089--5639
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; ATOM TRANSPORT; BONDING; CONFIGURATION INTERACTION; DISSOCIATION; ELECTRONIC STRUCTURE; ION CYCLOTRON-RESONANCE; MASS SPECTROSCOPY; OXIDATION; OXIDES; OXIDIZERS; PROTACTINIUM IONS

Citation Formats

Santos, M., de Matos, A. Pires, Marcalo, J., Gibson, John K, Haire, Richard, Tyagi, R., and Pitzer, R. M. Oxidation of Gas-Phase Protactinium Ions, Pa+ and Pa2+: Formation and Properties of PaO22+(g), Protactinyl. United States: N. p., 2006. Web. doi:10.1021/jp057297d.
Santos, M., de Matos, A. Pires, Marcalo, J., Gibson, John K, Haire, Richard, Tyagi, R., & Pitzer, R. M. Oxidation of Gas-Phase Protactinium Ions, Pa+ and Pa2+: Formation and Properties of PaO22+(g), Protactinyl. United States. https://doi.org/10.1021/jp057297d
Santos, M., de Matos, A. Pires, Marcalo, J., Gibson, John K, Haire, Richard, Tyagi, R., and Pitzer, R. M. 2006. "Oxidation of Gas-Phase Protactinium Ions, Pa+ and Pa2+: Formation and Properties of PaO22+(g), Protactinyl". United States. https://doi.org/10.1021/jp057297d.
@article{osti_1003302,
title = {Oxidation of Gas-Phase Protactinium Ions, Pa+ and Pa2+: Formation and Properties of PaO22+(g), Protactinyl},
author = {Santos, M. and de Matos, A. Pires and Marcalo, J. and Gibson, John K and Haire, Richard and Tyagi, R. and Pitzer, R. M.},
abstractNote = {Oxidation reactions of bare and ligated, monopositive, and dipositive Pa ions in the gas phase were studied by Fourier transform ion cyclotron resonance mass spectrometry. Seven oxidants were employed, ranging from the thermodynamically robust N{sub 2}O to the relatively weak CH{sub 2}O - all oxidized Pa{sup +} to PaO{sup +} and PaO{sup +} to PaO{sub 2}{sup +}. On the basis of experimental observations, it was established that D[Pa{sup +}-O] and D[OPa{sup +}-O] {ge} 751 kJ mol{sup -1}. Estimates for D[Pa{sup +}-O], D[OPa{sup +}-O], IE[PaO], and IE[PaO{sub 2}] were also obtained. The seven oxidants reacted with Pa{sup 2+} to produce PaO{sup 2+}, indicating that D[Pa{sup 2+}-O] {ge} 751 kJ mol{sup -1}. A particularly notable finding was the oxidation of PaO{sup 2+} by N{sub 2}O to PaO{sub 2}{sup 2+}, a species, which formally comprises Pa(VI). Collision-induced dissociation of PaO{sub 2}{sup 2+} suggested the protactinyl connectivity, {l_brace}O-Pa-O{r_brace}{sup 2+}. The experimentally determined IE[PaO{sub 2}{sup +}] {approx} 16.6 eV is in agreement with self-consistent-field and configuration interaction calculations for PaO{sub 2}{sup +} and PaO{sub 2}{sup 2+}. These calculations provide insights into the electronic structures of these ions and indicate the participation of 5f orbitals in bonding and a partial '6p hole' in the case of protactinyl. It was found that PaO{sub 2}{sup 2+} catalyzes the oxidation of CO by N{sub 2}O - such O atom transport via a dipositive metal oxide ion is distinctive. It was also observed that PaO{sub 2}{sup 2+} is capable of activating H{sub 2} to form the stable PaO{sub 2}H{sup 2+} ion.},
doi = {10.1021/jp057297d},
url = {https://www.osti.gov/biblio/1003302}, journal = {Journal of Physical Chemistry A},
issn = {1089--5639},
number = 17,
volume = 110,
place = {United States},
year = {Sun Jan 01 00:00:00 EST 2006},
month = {Sun Jan 01 00:00:00 EST 2006}
}