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Rubidium sesquioxide

Rubidium sesquioxide is a chemical compound with the formula Rb2O3 or more accurately Rb4O6. In terms of oxidation states, rubidium in this compound has a nominal charge of +1, and the oxygen is a mixed peroxide and superoxide for a structural formula of (Rb+)4(O−2)2(O2−2). It has been studied theoretically as an example of a strongly correlated material.

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Rubidium sesquioxide
Identifiers
3D model (JSmol)
  • InChI=1S/3O2.4Rb/c3*1-2;;;;/q-2;2*-1;4*+1
    Key: QZSXBJDVQYXYOD-UHFFFAOYSA-N
  • [Rb+].[Rb+].[Rb+].[Rb+].[O-][O-].O=[O-].O=[O-]
Properties
Rb4O6
Molar mass 437.865 g·mol−1
Appearance Black crystals1
Melting point 461 °C (862 °F; 734 K)2
Structure3
Pu2C3 structure type (body-centered cubic)
I43d (No. 220)
a = 932 pm
4
Related compounds
Other cations
 Caesium sesquioxide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Rubidium sesquioxide is a chemical compound with the formula Rb2O3 or more accurately Rb4O6. In terms of oxidation states, rubidium in this compound has a nominal charge of +1, and the oxygen is a mixed peroxide (O2−2) and superoxide (O−2) for a structural formula of (Rb+)4(O−2)2(O2−2).4 It has been studied theoretically as an example of a strongly correlated material.5

Structure

The compound crystallizes in a body-centered cubic form with the same crystal structure as Pu2C3 and Cs4O6.63

Preparation

Rubidium sesquioxide can be prepared by reacting the peroxide Rb2O2 and the superoxide RbO2:2

Rb2O2 + 2 RbO2 → 2 Rb2O3

History

It was initially discovered in 1907,73 and more thoroughly characterized in 1939.6

The compound was predicted to be a rare example of a ferromagnetic compound that is magnetic due to a p-block element,8 and a half-metal that was conducting in the minority spin band.9 However, while the material does have exotic magnetic behavior, experimental results instead showed an electrically insulating magnetically frustrated system.15 Rb4O6 also displays a Verwey transition where charge ordering appears at 290 K.10

References

References

  1. Winterlik, Jürgen; Fecher, Gerhard H.; Felser, Claudia; Mühle, Claus; Jansen, Martin (2007-05-15). "Challenging the Prediction of Anionogenic Ferromagnetism for Rb4O6". Journal of the American Chemical Society. 129 (22). American Chemical Society (ACS): 6990–6991. Bibcode:2007JAChS.129.6990W. doi:10.1021/ja071490z. ISSN 0002-7863. PMID 17500525.
  2. Jansen, Martin; Korber, Nikolaus (1991). "Neue Untersuchungen zu Präparation und Struktur von Rb4O6". Zeitschrift für anorganische und allgemeine Chemie (in German). 598 (1). Wiley: 163–173. Bibcode:1991ZAACh.598..163J. doi:10.1002/zaac.19915980116. ISSN 0044-2313.
  3. Jansen, Martin; Hagenmayer, Ralf; Korber, Nikolaus (1999). "Rb4O6 studied by elastic and inelastic neutron scattering". Comptes Rendus de l'Académie des Sciences, Série IIC. 2 (11–13). Elsevier BV: 591–594. doi:10.1016/s1387-1609(00)88570-9. ISSN 1387-1609.
  4. Winterlik, Jürgen; Fecher, Gerhard H.; Jenkins, Catherine A.; Medvedev, Sergey; Felser, Claudia; et al. (2009-06-09). "Exotic magnetism in the alkali sesquioxides Rb4O6 and Cs4O6". Physical Review B. 79 (21) 214410. arXiv:0904.4338. Bibcode:2009PhRvB..79u4410W. doi:10.1103/physrevb.79.214410. ISSN 1098-0121. S2CID 118706339.
  5. Winterlik, Jürgen; Fecher, Gerhard H.; Jenkins, Catherine A.; Felser, Claudia; Mühle, Claus; Doll, Klaus; Jansen, Martin; Sandratskii, Leonid M.; Kübler, Jürgen (2009-01-05). "Challenge of Magnetism in Strongly Correlated Open-Shell 2p Systems". Physical Review Letters. 102 (1) 016401. American Physical Society (APS). Bibcode:2009PhRvL.102a6401W. doi:10.1103/physrevlett.102.016401. ISSN 0031-9007. PMID 19257217.
  6. Helms, Alfred; Klemm, Wilhelm (1939-08-29). "Über die Kristallstrukturen der Rubidium- und Cäsiumsesquioxyde". Zeitschrift für anorganische und allgemeine Chemie (in German). 242 (2). Wiley: 201–214. Bibcode:1939ZAACh.242..201H. doi:10.1002/zaac.19392420210. ISSN 0863-1786.
  7. Rengade, M. E. (1907). "Contribution A L'Etude Des Oxydes Anhydres des Métaux Alcalins". Annales de chimie et de physique (in French). 11: 414.
  8. Attema, Jisk J.; de Wijs, Gilles A.; Blake, Graeme R.; de Groot, Robert A. (2005). "Anionogenic Ferromagnets" (PDF). Journal of the American Chemical Society. 127 (46). American Chemical Society (ACS): 16325–16328. Bibcode:2005JAChS.12716325A. doi:10.1021/ja0550834. hdl:11370/b216ba1e-93ed-418d-831d-cb32130d4db5. ISSN 0002-7863. PMID 16287327.
  9. Attema, J J; Wijs, G A de; Groot, R A de (2007-04-05). "Spintronic materials based on main-group elements" (PDF). Journal of Physics: Condensed Matter. 19 (16) 165203. IOP Publishing. Bibcode:2007JPCM...19p5203A. doi:10.1088/0953-8984/19/16/165203. ISSN 0953-8984.
  10. Knaflič, T.; Jeglič, P.; Komelj, M.; Zorko, A.; Biswas, P. K.; et al. (2020-01-22). "Spin-dimer ground state driven by consecutive charge and orbital ordering transitions in the anionic mixed-valence compound Rb4O6". Physical Review B. 101 (2) 024419. arXiv:1911.12049. Bibcode:2020PhRvB.101b4419K. doi:10.1103/physrevb.101.024419. ISSN 2469-9950. S2CID 208309918.