Molybdenum (II) oxide

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Structural formula
No drawing available
General
Surname Molybdenum (II) oxide
other names

Molybdenum monoxide

Molecular formula MoO
External identifiers / databases
CAS number 12058-07-0
EC number 235-026-3
ECHA InfoCard 100,031,830
Wikidata Q55259630
properties
Molar mass 111.96 g mol −1
Physical state

firmly

safety instructions
GHS hazard labeling
no classification available
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Molybdenum (II) oxide is an oxide of the transition metal molybdenum that has not yet been studied .

Condensed phase

Although most transition metals can assume the oxidation state II with suitable binding partners , - unlike in the case of divalent main group metals - monoxides of the transition metals are generally only accessible with difficulty. In the condensed phase , chemical compounds with the stoichiometry MoO are unknown as an independent species. Mentions in the early chemical literature by Bucholz and Berzelius have long been considered erroneous assignments. As with its lighter homologue chromium (II) oxide CrO, however, it is possible to produce thin layers of MoO on a carrier material. Such layers were formed in an ultra-high vacuum (10 −6  Pa) by oxidation of polycrystalline molybdenum at 200 ° C; at higher pressure, MoO 2 and MoO 4 are formed instead . By means of organometallic chemical vapor deposition at 400 ° C under nitrogen as an inert gas , thin, semiconducting MoO layers can be obtained on soda-lime glass ; here the acetylacetonato complex MoO 2 (acac) 2 with molybdenum in oxidation state VI serves as the predecessor.

Gas phase

The spectroscopic investigation of the diatomic MoO molecule in the gas phase was made more difficult in the past by heavy contamination with subnitrides , which form in the arc from molybdenum and nitrogen: 11 of 16 emission bands that were originally listed in the reference work of the Vatican Observatory for MoO were subsequently assigned to MoN. However, these difficulties have now been overcome; could u. a. the theoretically predicted ground state can be confirmed experimentally as 5 Π with a high-spin configuration 11σ 2 5π 4 2δ 2 12σ 1 6π 1 . The 11σ and 5π orbitals have a binding character, whereas the 2δ and 12σ orbitals located on the metal are non-binding. Electron donation yields MoO + , whose ground state is likely 4 Σ - (11σ 2 5π 4 12σ 1 2δ 2 ), with another deep δ 3 -configured 2 Δ state that has also been proposed as the ground state. Electron uptake leads to the MoO - molecule with a 4 Π ground state, whereby it is assumed that the additional electron is absorbed into the non-binding, spatially relatively extensive 12σ orbital, which is associated with the slightest additional electron-electron repulsion.

Individual evidence

  1. ↑ This substance has either not yet been classified with regard to its hazardousness or a reliable and citable source has not yet been found.
  2. ^ A. Wold, K. Dwight: Solid State Chemistry: Synthesis, Structure, and Properties of Selected Oxides and Sulfides . Chapmann & Hall, New York 1993, p. 90.
  3. ↑ JJ Berzelius: Schweigger's Journ. Volume 22, 1817, p. 51; online at http://www.archive.org/stream/journalfrchemie69unkngoog#page/n63/mode/2up
  4. ^ JW Mellor: A Comprehensive Treatise on Inorganic and Theoretical Chemistry. Vol. 9, Longmans, London 1948, p. 525.
  5. ^ NS McIntyre, DD Johnston, LL Coatsworth, RD Davidson, JR Brown: Surf. Interface Anal. Volume 15, 1990, p. 262
  6. ↑ OO Ilori, O. Osasona, MA Eleruja, GO Egharevba, GA Adegboyega, G. Chiodelli, G. Boudreault, C. Jeynes, EOB Ajayi: Thin Solid Films Volume 472, 2005, p. 84
  7. ↑ A. Gatterer, J. Junkes, EW Salpeter: Molecular Spectra of Metallic Oxides. Specola Vaticana, Vatican City 1957, p. 54.
  8. ↑ RC Carlson, JK Bates, T. Dunn: J. Mol. Spectrocsc. Volume 110, 1985, p. 215
  9. ↑ SR Langhoff, CW Bauschlicher Jr: Ann. Rev. Phys. Chem. Vol. 39, 1988, p. 181
  10. ↑ CW Bauschlicher Jr., CJ Nelin, PS Bagus: J. Chem. Phys. Volume 82, 1985, p. 3265
  11. ↑ CJ Nelin, CW Bauschlicher Jr: Chem. Phys. Lett. Volume 118, 1985, p. 221
  12. ^ YM Hamrick, S. Taylor, MD Morse: J. Mol. Spectrosc. Volume 146, 1991, p. 274
  13. ↑ H.-P. Loock, B. Simard, S. Wallin, C. Linton: J. Chem. Phys. Volume 109, 1998, p. 8980
  14. ↑ E. Brocławik: Int. J. Quantum Chem. Vol. 56, 1995, p. 779
  15. ^ RF Gunion, J. Dixon-Warren, WC Lineberger, MD Morse: J. Chem. Phys. Volume 104, 1996, p. 1765.