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Article

Mass Spectrometric and Quantum Chemical Studies of the Thermodynamics and Bonding of Neutral and Ionized LnCl, LnCl₂, and LnCl₃ Species (Ln = Ce, Lu)

Supporting Info

Julia Saloni,^†^‡ Szczepan Roszak,*^†^‡ Klaus Hilpert,^§ Arkadij Popovic, Mirosław Miller, and Jerzy Leszczynski^†

Computational Center for Molecular Structure and Interactions, Jackson State University, Jackson, Mississippi 39217, Institute of Physical and Theoretical Chemistry, Wroclaw University of Technology, Wybrzee Wyspiaskiego 27, 50-370 Wroclaw, Poland, Research Center Jlich, Institute for Materials and Processes in Energy Systems, 52425 Jlich, Germany, Jozef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia, and Faculty of Chemistry, Wroclaw University of Technology, Wybrzee Wyspiaskiego 27, 50-370 Wroclaw, Poland

Inorg. Chem., 2006, 45 (11), pp 4508–4517

DOI: 10.1021/ic051205h

Publication Date (Web): May 5, 2006

†

Computational Center for Molecular Structure and Interactions, Jackson State University.

‡

Institute of Physical and Theoretical Chemistry, Wroclaw University of Technology.

To whom correspondence should be addressed. Fax: +4871 3203364. E-mail: szczepan.roszak@pwr.wroc.pl.

Research Center Jülich, Institute for Materials and Processes in Energy Systems.

Jozef Stefan Institute.

Faculty of Chemistry, Wroclaw University of Technology.

Abstract

The mass spectral patterns of CeCl₃(g) and LuCl₃(g) and appearance energies for the identified ions were measured using a Nier-type mass spectrometer coupled with a Knudsen cell. The molecular ion CeCl₃⁺ was found to be considerably less stable in comparison to LuCl₃⁺. Partial pressures and sublimation enthalpies of LnCl₃(s) to monomeric LnCl₃(g) and dimeric Ln₂Cl₆(g) species were obtained in the ranges of 882−1028 (Ln = Ce) and 850−1004 K (Ln = Lu). The contribution of dimeric Ce₂Cl₆(g) species to equilibrium vapors of CeCl₃(s) is considerably smaller than the Lu₂Cl₆(g) contribution in LuCl₃(s) vapors. The measurements were supplemented by quantum chemical ab initio studies of structures, energetics, and vibrational frequencies of neutral and singly ionized LnCl, LnCl₂, and LnCl₃ species (Ln = Ce, Lu). The theoretical appearance energies of different ions, calculated from the energies of the gaseous species, are in good agreement with experimental data. The fragmentation energies of LnCl, LnCl₂, and LnCl₃ were also computed and compared with the mass spectral patterns of respective vapor species. The Mulliken and natural bond orbital electron population methods were applied for the systematic analysis of the bonding scheme in molecules and cations.