In
chemistry, phi bonds (φ bonds) are
covalent chemical bond
A chemical bond is a lasting attraction between atoms or ions that enables the formation of molecules and crystals. The bond may result from the electrostatic force between oppositely charged ions as in ionic bonds, or through the sharing o ...
s, where six lobes of one involved
atomic orbital
In atomic theory and quantum mechanics, an atomic orbital is a function describing the location and wave-like behavior of an electron in an atom. This function can be used to calculate the probability of finding any electron of an atom in any sp ...
overlap
Overlap may refer to:
* In set theory, an overlap of elements shared between sets is called an intersection, as in a Venn diagram.
* In music theory, overlap is a synonym for reinterpretation of a chord at the boundary of two musical phrases
* Ove ...
six lobes of the other involved atomic orbital. This overlap leads to the formation of a bonding
molecular orbital
In chemistry, a molecular orbital is a mathematical function describing the location and wave-like behavior of an electron in a molecule. This function can be used to calculate chemical and physical properties such as the probability of findin ...
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 known in 2005 of a molecule with phi bonding (a U−U bond, in the molecule
U2). However, later studies that accounted for spin orbit interactions found that the bonding was only of
fourth order.
Experimental evidence of existence of phi bonding between a
thorium atom and
cyclooctatetraene
1,3,5,7-Cyclooctatetraene (COT) is an unsaturated derivative of cyclooctane, with the formula C8H8. It is also known as nnulene. This polyunsaturated hydrocarbon is a colorless to light yellow flammable liquid at room temperature. Because of ...
in
thorocene has been shown, supported by computational analysis.
References
{{Chemical bonding theory
Chemical bonding
Hypothetical processes