View source for Physics:Quantum phi bond

{{Short description|Type of chemical bond}}

{{Quantum matter backlink|Molecules}}

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{{distinguish|Pi bond}}
{{multiple image
| footer    = Suitably-aligned f atomic orbitals can overlap to form a φ molecular orbital (a φ bond)
| width     = 120
| image1    = Phi-bond-f-orbitals-2D.png
| image2    = Phi-bond-boundary-surface-diagram-2D.png
| caption   = Suitably-aligned f atomic orbitals can overlap to form a φ molecular orbital (a φ bond)
}}
In [[HandWiki:Chemistry|chemistry]], '''phi bonds''' ('''φ bonds''') are usually [[Chemistry:Covalent bond|covalent]] [[Chemistry:Chemical bond|chemical bond]]s, where six lobes of one involved [[Physics:Atomic orbital|atomic orbital]] [[Orbital overlap|overlap]] six lobes of the other involved atomic orbital. This overlap leads to the formation of a bonding [[Chemistry:Molecular orbital|molecular orbital]] with three nodal planes which contain the internuclear axis and go through both atoms.

The Greek letter φ in their name refers to f orbitals, since the orbital symmetry of the φ bond is the same as that of the usual (6-lobed) type of f orbital when seen down the bond axis.

There was one possible candidate reported in 2005 of a molecule with phi bonding: a U−U bond in the molecule diuranium (U<sub>2</sub>).<ref>{{cite journal|last1=Gagliardi|first1=Laura|last2=Roos|first2=Björn O.|title=Quantum chemical calculations show that the uranium molecule U<sub>2</sub> has a quintuple bond|journal=Nature|year=2005|volume=433|issue=7028|pages=848–851|doi=10.1038/nature03249|url=http://archive-ouverte.unige.ch/unige:3652|bibcode = 2005Natur.433..848G|pmid=15729337|s2cid=421380}}</ref> However, later studies that accounted for [[Physics:Spin–orbit interaction|spin–orbit interaction]]s found that the bonding was only of [[Chemistry:Quadruple bond|fourth order]].<ref name = Manz2017>{{cite journal | doi = 10.1039/c7ra07400j | journal = RSC Adv. | title = Introducing DDEC6 atomic population analysis: part 3. Comprehensive method to compute bond orders | author1 = T. A. Manz | year = 2017 | volume = 7 | issue = 72 | pages = 45552–45581| bibcode = 2017RSCAd...745552M |doi-access = free}}</ref><ref>{{Cite web|url=https://chab.ethz.ch/en/news-and-events/d-chab-news/2018/10/u2-the-diuran-molecule-has-a-quadruple-bond.html|title=The diuranium molecule has a quadruple bond|website=chab.ethz.ch|date=28 October 2018 |language=en|access-date=2020-03-21}}</ref><ref name=":0">{{Cite journal|last1=Knecht|first1=Stefan|last2=Jensen|first2=Hans Jørgen Aa|last3=Saue|first3=Trond|date=January 2019|title=Relativistic quantum chemical calculations show that the uranium molecule U<sub>2</sub> has a quadruple bond|journal=Nature Chemistry|language=en|volume=11|issue=1|pages=40–44|doi=10.1038/s41557-018-0158-9|pmid=30374039|bibcode=2019NatCh..11...40K |s2cid=53112083|issn=1755-4349}}</ref> Experimental evidence for phi bonding between a [[Chemistry:Thorium|thorium]] atom and [[Chemistry:Cyclooctatetraene|cyclooctatetraene]] in [[Chemistry:Thorocene|thorocene]] has been supported by computational analysis, though this mixed-orbital bond has strong ionic character and is not a traditional phi bond.<ref>{{Cite journal |last1=Minasian |first1=Stefan G. |last2=Keith |first2=Jason M. |last3=Batista |first3=Enrique R. |last4=Boland |first4=Kevin S. |last5=Clark |first5=David L. |last6=Kozimor |first6=Stosh A. |last7=Martin |first7=Richard L. |last8=Shuh |first8=David K. |last9=Tyliszczak |first9=Tolek |date=2014 |title=New evidence for 5f covalency in actinocenes determined from carbon K-edge XAS and electronic structure theory |journal=Chem. Sci. |language=en |volume=5 |issue=1 |pages=351–359 |doi=10.1039/C3SC52030G |issn=2041-6520}}</ref>
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== References ==
{{Reflist}}
{{Chemical bonding theory}}

[[Category:Chemical bonding]]

{{Sourceattribution|Phi bond}}