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WikiHarold moved page Chemistry:Delta bond to Physics:Quantum delta bond without leaving a redirect

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imported>WikiHarold: WikiHarold moved page Chemistry:Delta bond to Physics:Quantum delta bond without leaving a redirect

2026-05-04T17:10:14Z

WikiHarold moved page Chemistry:Delta bond to Physics:Quantum delta bond without leaving a redirect

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{{Short description|Type of chemical bond}}
[[File:Delta-bond-formation-2D.png|thumb|right|200px|Formation of a δ bond by the overlap of two d orbitals]]
[[File:Dimolybdenum-Mo2-delta-bond-Spartan-HF-3-21G-3D-side.png|thumb|right|200px|3D model of a boundary surface of a δ bond in Mo2]]

In [[HandWiki:Chemistry|chemistry]], a '''delta bond''' ('''δ bond''') is a [[Chemistry:Covalent bond|covalent]] [[Chemistry:Chemical bond|chemical bond]], in which four lobes of an [[Physics:Atomic orbital|atomic orbital]] on one atom [[Orbital overlap|overlap]] four lobes of an atomic orbital on another atom. This overlap leads to the formation of a bonding [[Chemistry:Molecular orbital|molecular orbital]] with two nodal planes which contain the internuclear axis and go through both atoms.<ref>{{cite book|title=Advanced Inorganic Chemistry|last2=Wilkinson|first2=G.|date=1988|publisher=John Wiley|isbn=0-471-84997-9|edition=5th|pages=1087–1091|first1=F. A.|last1=Cotton|author2-link=Geoffrey Wilkinson}}</ref><ref>{{cite book|title=Concepts and Models of Inorganic Chemistry|url=https://archive.org/details/conceptsmodelsof0000doug|url-access=registration|last2=McDaniel|first2=D. H.|last3=Alexander|first3=J. J.|date=1983|publisher=Wiley|isbn=9780471895053|edition=2nd|page=[https://archive.org/details/conceptsmodelsof0000doug/page/137 137]|first1=B.|last1=Douglas}}</ref><ref>{{cite book|title=Inorganic Chemistry|last=Huheey|first=J. E.|date=1983|publisher=Harper and Row|isbn=9780060429874|edition=3rd|pages=743–744}}</ref><ref>{{cite book|title=Inorganic Chemistry|last2=Tarr|first2=D. A.|date=1998|publisher=Prentice-Hall|isbn=978-0138418915|edition=2nd|pages=123–124|first1=G. L.|last1=Miessler}}</ref>

The Greek letter δ in their name refers to d orbitals, since the orbital symmetry of the δ bond is the same as that of the usual (4-lobed) type of d orbital when seen down the bond axis. This type of bonding is observed in atoms that have occupied d orbitals with low enough energy to participate in covalent bonding, for example, in organometallic species of [[Chemistry:Transition metal|transition metal]]s. Some [[Chemistry:Rhenium|rhenium]], [[Chemistry:Molybdenum|molybdenum]], [[Chemistry:Technetium|technetium]], and [[Chemistry:Chromium|chromium]] compounds contain a [[Chemistry:Quadruple bond|quadruple bond]], consisting of one [[Chemistry:Sigma bond|σ bond]], two [[Chemistry:Pi bond|π bond]]s and one δ bond. In the case of the [Re2Cl8]2- ion in the D4h [[Point group]], the [[Chemistry:Bonding molecular orbital|bonding]] delta interaction is the highest energy bonding interaction, followed by the bonding pi, and sigma interactions. The resultant [[Chemistry:Antibonding molecular orbital|antibonding]] delta interaction is the least destabilized, followed by the antibonding pi and sigma interactions.<ref>{{Cite journal |last=Falvello |first=Larry R. |last2=Foxman |first2=Bruce M. |last3=Murillo |first3=Carlos A. |date=2014-09-15 |title=Fitting the Pieces of the Puzzle: The δ Bond |url=https://pubs.acs.org/doi/10.1021/ic500119h |journal=Inorganic Chemistry |language=en |volume=53 |issue=18 |pages=9441–9456 |doi=10.1021/ic500119h |issn=0020-1669}}</ref>

[[File:Molecular orbital diagram of d orbitals in D4h Re2Cl8.jpg|thumb|Molecular Orbital Diagram of D4h [Re2Cl8<nowiki>]</nowiki>2- showing the bonding and antibonding d orbital interactions and their relative energies. the dx2-y2 is omitted from d-d interactions due to its engagement with chloride ligands]]
The orbital symmetry of the δ bonding orbital is different from that of a [[Chemistry:Pi bond|π]] antibonding orbital, which has one nodal plane containing the internuclear axis and a second nodal plane perpendicular to this axis between the atoms.

The δ notation was introduced by Robert Mulliken in 1931.<ref>{{cite journal|title=The Origin of the Sigma, Pi, Delta Notation for Chemical Bonds|first=William B.|last=Jensen|journal=J. Chem. Educ.|date=2013|volume=90|issue=6|pages=802–803|doi=10.1021/ed200298h|bibcode=2013JChEd..90..802J}}</ref><ref>{{cite journal|title=Bonding Power of Electrons and Theory of Valence|first=Robert S.|last=Mulliken|journal=[[Chemistry:Chemical Reviews|Chem. Rev.]]|date=1931|volume=9|issue=3|pages=347–388|doi=10.1021/cr60034a001}}</ref> The first compound identified as having a δ bond was [[Chemistry:Potassium octachlorodirhenate|potassium octachlorodirhenate(III)]]. In 1965, F. A. Cotton reported that there was δ-bonding as part of the rhenium–rhenium [[Chemistry:Quadruple bond|quadruple bond]] in the [Re2Cl8]2− ion.<ref>{{cite journal|title=Metal–Metal Bonding in [Re2X8]2− Ions and Other Metal Atom Clusters|first=F. A.|last=Cotton|journal=Inorg. Chem.|date=1965|volume=4|issue=3|pages=334–336|doi=10.1021/ic50025a016}}</ref> Another example of a δ bond is proposed in [[Chemistry:Cyclobutadieneiron tricarbonyl|cyclobutadieneiron tricarbonyl]] between an iron d orbital and the four p orbitals of the attached cyclobutadiene molecule.

== References ==
{{Reflist}}

{{Chemical bonding theory}}

{{DEFAULTSORT:Delta Bond}}
[[Category:Chemical bonding]]

{{Sourceattribution|Delta bond}}

Physics:Quantum delta bond - Revision history

imported>WikiHarold: WikiHarold moved page Chemistry:Delta bond to Physics:Quantum delta bond without leaving a redirect

imported>WikiHarold: WikiHarold moved page Chemistry:Delta bond to Physics:Quantum delta bond without leaving a redirect