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Quantum chemical calculations show that the uranium molecule U-2 has a quintuple bond

Gagliardi, L and Roos, Björn LU (2005) In Nature 433(7028). p.848-851
Abstract
Covalent bonding is commonly described by Lewis's theory(1), with an electron pair shared between two atoms constituting one full bond. Beginning with the valence bond description(2) for the hydrogen molecule, quantum chemists have further explored the fundamental nature of the chemical bond for atoms throughout the periodic table, confirming that most molecules are indeed held together by one electron pair for each bond. But more complex binding may occur when large numbers of atomic orbitals can participate in bond formation. Such behaviour is common with transition metals. When involving heavy actinide elements, metal-metal bonds might prove particularly complicated. To date, evidence for actinide-actinide bonds is restricted to the... (More)
Covalent bonding is commonly described by Lewis's theory(1), with an electron pair shared between two atoms constituting one full bond. Beginning with the valence bond description(2) for the hydrogen molecule, quantum chemists have further explored the fundamental nature of the chemical bond for atoms throughout the periodic table, confirming that most molecules are indeed held together by one electron pair for each bond. But more complex binding may occur when large numbers of atomic orbitals can participate in bond formation. Such behaviour is common with transition metals. When involving heavy actinide elements, metal-metal bonds might prove particularly complicated. To date, evidence for actinide-actinide bonds is restricted to the matrix-isolation(3) of uranium hydrides, including H2U-UH2, and the gas-phase detection(4) and preliminary theoretical study(5) of the uranium molecule, U-2. Here we report quantum chemical calculations on U-2, showing that, although the strength of the U-2 bond is comparable to that of other multiple bonds between transition metals, the bonding pattern is unique. We find that the molecule contains three electron-pair bonds and four one-electron bonds (that is, 10 bonding electrons, corresponding to a quintuple bond), and two ferromagnetically coupled electrons localized on one U atom each-so all known covalent bonding types are contributing. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Nature
volume
433
issue
7028
pages
848 - 851
publisher
Nature Publishing Group
external identifiers
  • wos:000227174600037
  • pmid:15729337
  • scopus:14744275228
ISSN
0028-0836
DOI
10.1038/nature03249
language
English
LU publication?
yes
id
ef8f9198-cf51-492c-91b8-dde9fa103f79 (old id 152796)
date added to LUP
2007-07-17 09:42:45
date last changed
2017-11-19 03:34:34
@article{ef8f9198-cf51-492c-91b8-dde9fa103f79,
  abstract     = {Covalent bonding is commonly described by Lewis's theory(1), with an electron pair shared between two atoms constituting one full bond. Beginning with the valence bond description(2) for the hydrogen molecule, quantum chemists have further explored the fundamental nature of the chemical bond for atoms throughout the periodic table, confirming that most molecules are indeed held together by one electron pair for each bond. But more complex binding may occur when large numbers of atomic orbitals can participate in bond formation. Such behaviour is common with transition metals. When involving heavy actinide elements, metal-metal bonds might prove particularly complicated. To date, evidence for actinide-actinide bonds is restricted to the matrix-isolation(3) of uranium hydrides, including H2U-UH2, and the gas-phase detection(4) and preliminary theoretical study(5) of the uranium molecule, U-2. Here we report quantum chemical calculations on U-2, showing that, although the strength of the U-2 bond is comparable to that of other multiple bonds between transition metals, the bonding pattern is unique. We find that the molecule contains three electron-pair bonds and four one-electron bonds (that is, 10 bonding electrons, corresponding to a quintuple bond), and two ferromagnetically coupled electrons localized on one U atom each-so all known covalent bonding types are contributing.},
  author       = {Gagliardi, L and Roos, Björn},
  issn         = {0028-0836},
  language     = {eng},
  number       = {7028},
  pages        = {848--851},
  publisher    = {Nature Publishing Group},
  series       = {Nature},
  title        = {Quantum chemical calculations show that the uranium molecule U-2 has a quintuple bond},
  url          = {http://dx.doi.org/10.1038/nature03249},
  volume       = {433},
  year         = {2005},
}