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	<id>https://handwiki.scholarlywiki.org/index.php?action=history&amp;feed=atom&amp;title=Physics%3AQuantum_delta_bond</id>
	<title>Physics:Quantum delta bond - Revision history</title>
	<link rel="self" type="application/atom+xml" href="https://handwiki.scholarlywiki.org/index.php?action=history&amp;feed=atom&amp;title=Physics%3AQuantum_delta_bond"/>
	<link rel="alternate" type="text/html" href="https://handwiki.scholarlywiki.org/index.php?title=Physics:Quantum_delta_bond&amp;action=history"/>
	<updated>2026-06-24T17:53:49Z</updated>
	<subtitle>Revision history for this page on the wiki</subtitle>
	<generator>MediaWiki 1.45.3</generator>
	<entry>
		<id>https://handwiki.scholarlywiki.org/index.php?title=Physics:Quantum_delta_bond&amp;diff=10056&amp;oldid=prev</id>
		<title>WikiHarold: Finish Quantum residual red link cleanup</title>
		<link rel="alternate" type="text/html" href="https://handwiki.scholarlywiki.org/index.php?title=Physics:Quantum_delta_bond&amp;diff=10056&amp;oldid=prev"/>
		<updated>2026-05-23T23:54:31Z</updated>

		<summary type="html">&lt;p&gt;Finish Quantum residual red link cleanup&lt;/p&gt;
&lt;table style=&quot;background-color: #fff; color: #202122;&quot; data-mw=&quot;interface&quot;&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
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				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;← Older revision&lt;/td&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;Revision as of 23:54, 23 May 2026&lt;/td&gt;
				&lt;/tr&gt;&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l16&quot;&gt;Line 16:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 16:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;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 transition metals. Some rhenium, molybdenum, technetium, and chromium compounds contain a quadruple bond, consisting of one σ bond, two π bonds and one δ bond. In the case of the [Re&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;Cl&amp;lt;sub&amp;gt;8&amp;lt;/sub&amp;gt;]&amp;lt;sup&amp;gt;2-&amp;lt;/sup&amp;gt; ion in the D&amp;lt;sub&amp;gt;4h&amp;lt;/sub&amp;gt; Point group, the bonding delta interaction is the highest energy bonding interaction, followed by the bonding pi, and sigma interactions. The resultant antibonding delta interaction is the least destabilized, followed by the antibonding pi and sigma interactions.&amp;lt;ref&amp;gt;{{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}}&amp;lt;/ref&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;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 transition metals. Some rhenium, molybdenum, technetium, and chromium compounds contain a quadruple bond, consisting of one σ bond, two π bonds and one δ bond. In the case of the [Re&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;Cl&amp;lt;sub&amp;gt;8&amp;lt;/sub&amp;gt;]&amp;lt;sup&amp;gt;2-&amp;lt;/sup&amp;gt; ion in the D&amp;lt;sub&amp;gt;4h&amp;lt;/sub&amp;gt; Point group, the bonding delta interaction is the highest energy bonding interaction, followed by the bonding pi, and sigma interactions. The resultant antibonding delta interaction is the least destabilized, followed by the antibonding pi and sigma interactions.&amp;lt;ref&amp;gt;{{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}}&amp;lt;/ref&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;[[File:Molecular orbital diagram of d orbitals in D4h Re2Cl8.jpg|thumb|Molecular Orbital Diagram of D&amp;lt;sub&amp;gt;4h&amp;lt;/sub&amp;gt; [Re&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;Cl&amp;lt;sub&amp;gt;8&amp;lt;/sub&amp;gt;&amp;lt;nowiki&amp;gt;]&amp;lt;/nowiki&amp;gt;&amp;lt;sup&amp;gt;2-&amp;lt;/sup&amp;gt; showing the bonding and antibonding d orbital interactions and their relative energies. the d&amp;lt;sub&amp;gt;x&amp;lt;/sub&amp;gt;&amp;lt;sup&amp;gt;2&amp;lt;/sup&amp;gt;&amp;lt;sub&amp;gt;-y&amp;lt;/sub&amp;gt;&amp;lt;sup&amp;gt;2&amp;lt;/sup&amp;gt; is omitted from d-d interactions due to its engagement with chloride ligands]]&lt;/del&gt;&lt;/div&gt;&lt;/td&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-added&quot;&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;The orbital symmetry of the δ bonding orbital is different from that of a π antibonding orbital, which has one nodal plane containing the internuclear axis and a second nodal plane perpendicular to this axis between the atoms.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;The orbital symmetry of the δ bonding orbital is different from that of a π antibonding orbital, which has one nodal plane containing the internuclear axis and a second nodal plane perpendicular to this axis between the atoms.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;/table&gt;</summary>
		<author><name>WikiHarold</name></author>
	</entry>
	<entry>
		<id>https://handwiki.scholarlywiki.org/index.php?title=Physics:Quantum_delta_bond&amp;diff=9983&amp;oldid=prev</id>
		<title>WikiHarold: Remove imported red links from Quantum page</title>
		<link rel="alternate" type="text/html" href="https://handwiki.scholarlywiki.org/index.php?title=Physics:Quantum_delta_bond&amp;diff=9983&amp;oldid=prev"/>
		<updated>2026-05-23T23:47:04Z</updated>

		<summary type="html">&lt;p&gt;Remove imported red links from Quantum page&lt;/p&gt;
&lt;table style=&quot;background-color: #fff; color: #202122;&quot; data-mw=&quot;interface&quot;&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
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				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;← Older revision&lt;/td&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;Revision as of 23:47, 23 May 2026&lt;/td&gt;
				&lt;/tr&gt;&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l30&quot;&gt;Line 30:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 30:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;== References ==&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;== References ==&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;{{Reflist}}&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;{{Reflist}}&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;&lt;/del&gt;&lt;/div&gt;&lt;/td&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-added&quot;&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;{{Chemical bonding theory}}&lt;/del&gt;&lt;/div&gt;&lt;/td&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-added&quot;&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;{{DEFAULTSORT:Delta Bond}}&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;{{DEFAULTSORT:Delta Bond}}&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;[[Category:Chemical bonding]]&lt;/del&gt;&lt;/div&gt;&lt;/td&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-added&quot;&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;{{Sourceattribution|Delta bond}}&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;{{Sourceattribution|Delta bond}}&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;/table&gt;</summary>
		<author><name>WikiHarold</name></author>
	</entry>
	<entry>
		<id>https://handwiki.scholarlywiki.org/index.php?title=Physics:Quantum_delta_bond&amp;diff=9771&amp;oldid=prev</id>
		<title>WikiHarold: Clean Quantum page image and red links</title>
		<link rel="alternate" type="text/html" href="https://handwiki.scholarlywiki.org/index.php?title=Physics:Quantum_delta_bond&amp;diff=9771&amp;oldid=prev"/>
		<updated>2026-05-23T23:33:58Z</updated>

		<summary type="html">&lt;p&gt;Clean Quantum page image and red links&lt;/p&gt;
&lt;table style=&quot;background-color: #fff; color: #202122;&quot; data-mw=&quot;interface&quot;&gt;
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				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;← Older revision&lt;/td&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;Revision as of 23:33, 23 May 2026&lt;/td&gt;
				&lt;/tr&gt;&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l12&quot;&gt;Line 12:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 12:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;[[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 Mo&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;]]&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;[[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 Mo&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;]]&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;In &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;[[HandWiki:Chemistry|&lt;/del&gt;chemistry&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;]]&lt;/del&gt;, a &#039;&#039;&#039;delta bond&#039;&#039;&#039; (&#039;&#039;&#039;δ bond&#039;&#039;&#039;) is a &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;[[Chemistry:Covalent bond|&lt;/del&gt;covalent&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;]] [[Chemistry:Chemical bond|&lt;/del&gt;chemical bond&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;]]&lt;/del&gt;, in which four lobes of an &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;[[Physics:Atomic orbital|&lt;/del&gt;atomic orbital&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;]] &lt;/del&gt;on one atom &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;[[Orbital &lt;/del&gt;overlap&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;|overlap]] &lt;/del&gt;four lobes of an atomic orbital on another atom. This overlap leads to the formation of a bonding &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;[[Chemistry:Molecular orbital|&lt;/del&gt;molecular orbital&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;]] &lt;/del&gt;with two nodal planes which contain the internuclear axis and go through both atoms.&amp;lt;ref&amp;gt;{{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}}&amp;lt;/ref&amp;gt;&amp;lt;ref&amp;gt;{{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}}&amp;lt;/ref&amp;gt;&amp;lt;ref&amp;gt;{{cite book|title=Inorganic Chemistry|last=Huheey|first=J. E.|date=1983|publisher=Harper and Row|isbn=9780060429874|edition=3rd|pages=743–744}}&amp;lt;/ref&amp;gt;&amp;lt;ref&amp;gt;{{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}}&amp;lt;/ref&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;In chemistry, a &#039;&#039;&#039;delta bond&#039;&#039;&#039; (&#039;&#039;&#039;δ bond&#039;&#039;&#039;) is a covalent chemical bond, in which four lobes of an atomic orbital on one atom overlap four lobes of an atomic orbital on another atom. This overlap leads to the formation of a bonding molecular orbital with two nodal planes which contain the internuclear axis and go through both atoms.&amp;lt;ref&amp;gt;{{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}}&amp;lt;/ref&amp;gt;&amp;lt;ref&amp;gt;{{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}}&amp;lt;/ref&amp;gt;&amp;lt;ref&amp;gt;{{cite book|title=Inorganic Chemistry|last=Huheey|first=J. E.|date=1983|publisher=Harper and Row|isbn=9780060429874|edition=3rd|pages=743–744}}&amp;lt;/ref&amp;gt;&amp;lt;ref&amp;gt;{{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}}&amp;lt;/ref&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;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 &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;[[Chemistry:Transition metal|&lt;/del&gt;transition &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;metal]]s&lt;/del&gt;. Some &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;[[Chemistry:Rhenium|&lt;/del&gt;rhenium&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;]]&lt;/del&gt;, &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;[[Chemistry:Molybdenum|&lt;/del&gt;molybdenum&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;]]&lt;/del&gt;, &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;[[Chemistry:Technetium|&lt;/del&gt;technetium&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;]]&lt;/del&gt;, and &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;[[Chemistry:Chromium|&lt;/del&gt;chromium&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;]] &lt;/del&gt;compounds contain a &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;[[Chemistry:Quadruple bond|&lt;/del&gt;quadruple bond&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;]]&lt;/del&gt;, consisting of one &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;[[Chemistry:Sigma bond|&lt;/del&gt;σ bond&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;]]&lt;/del&gt;, two &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;[[Chemistry:Pi bond|&lt;/del&gt;π &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;bond]]s &lt;/del&gt;and one δ bond. In the case of the [Re&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;Cl&amp;lt;sub&amp;gt;8&amp;lt;/sub&amp;gt;]&amp;lt;sup&amp;gt;2-&amp;lt;/sup&amp;gt; ion in the D&amp;lt;sub&amp;gt;4h&amp;lt;/sub&amp;gt; &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;[[&lt;/del&gt;Point group&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;]]&lt;/del&gt;, the &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;[[Chemistry:Bonding molecular orbital|&lt;/del&gt;bonding&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;]] &lt;/del&gt;delta interaction is the highest energy bonding interaction, followed by the bonding pi, and sigma interactions. The resultant &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;[[Chemistry:Antibonding molecular orbital|&lt;/del&gt;antibonding&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;]] &lt;/del&gt;delta interaction is the least destabilized, followed by the antibonding pi and sigma interactions.&amp;lt;ref&amp;gt;{{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}}&amp;lt;/ref&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;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 transition &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;metals&lt;/ins&gt;. Some rhenium, molybdenum, technetium, and chromium compounds contain a quadruple bond, consisting of one σ bond, two π &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;bonds &lt;/ins&gt;and one δ bond. In the case of the [Re&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;Cl&amp;lt;sub&amp;gt;8&amp;lt;/sub&amp;gt;]&amp;lt;sup&amp;gt;2-&amp;lt;/sup&amp;gt; ion in the D&amp;lt;sub&amp;gt;4h&amp;lt;/sub&amp;gt; Point group, the bonding delta interaction is the highest energy bonding interaction, followed by the bonding pi, and sigma interactions. The resultant antibonding delta interaction is the least destabilized, followed by the antibonding pi and sigma interactions.&amp;lt;ref&amp;gt;{{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}}&amp;lt;/ref&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;[[File:Molecular orbital diagram of d orbitals in D4h Re2Cl8.jpg|thumb|Molecular Orbital Diagram of D&amp;lt;sub&amp;gt;4h&amp;lt;/sub&amp;gt; [Re&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;Cl&amp;lt;sub&amp;gt;8&amp;lt;/sub&amp;gt;&amp;lt;nowiki&amp;gt;]&amp;lt;/nowiki&amp;gt;&amp;lt;sup&amp;gt;2-&amp;lt;/sup&amp;gt; showing the bonding and antibonding d orbital interactions and their relative energies. the d&amp;lt;sub&amp;gt;x&amp;lt;/sub&amp;gt;&amp;lt;sup&amp;gt;2&amp;lt;/sup&amp;gt;&amp;lt;sub&amp;gt;-y&amp;lt;/sub&amp;gt;&amp;lt;sup&amp;gt;2&amp;lt;/sup&amp;gt; is omitted from d-d interactions due to its engagement with chloride ligands]]&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;[[File:Molecular orbital diagram of d orbitals in D4h Re2Cl8.jpg|thumb|Molecular Orbital Diagram of D&amp;lt;sub&amp;gt;4h&amp;lt;/sub&amp;gt; [Re&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;Cl&amp;lt;sub&amp;gt;8&amp;lt;/sub&amp;gt;&amp;lt;nowiki&amp;gt;]&amp;lt;/nowiki&amp;gt;&amp;lt;sup&amp;gt;2-&amp;lt;/sup&amp;gt; showing the bonding and antibonding d orbital interactions and their relative energies. the d&amp;lt;sub&amp;gt;x&amp;lt;/sub&amp;gt;&amp;lt;sup&amp;gt;2&amp;lt;/sup&amp;gt;&amp;lt;sub&amp;gt;-y&amp;lt;/sub&amp;gt;&amp;lt;sup&amp;gt;2&amp;lt;/sup&amp;gt; is omitted from d-d interactions due to its engagement with chloride ligands]]&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;The orbital symmetry of the δ bonding orbital is different from that of a &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;[[Chemistry:Pi bond|&lt;/del&gt;π&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;]] &lt;/del&gt;antibonding orbital, which has one nodal plane containing the internuclear axis and a second nodal plane perpendicular to this axis between the atoms.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;The orbital symmetry of the δ bonding orbital is different from that of a π antibonding orbital, which has one nodal plane containing the internuclear axis and a second nodal plane perpendicular to this axis between the atoms.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;The δ notation was introduced by Robert Mulliken in 1931.&amp;lt;ref&amp;gt;{{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}}&amp;lt;/ref&amp;gt;&amp;lt;ref&amp;gt;{{cite journal|title=Bonding Power of Electrons and Theory of Valence|first=Robert S.|last=Mulliken|journal=&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;[[Chemistry:Chemical Reviews|&lt;/del&gt;Chem. Rev.&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;]]&lt;/del&gt;|date=1931|volume=9|issue=3|pages=347–388|doi=10.1021/cr60034a001}}&amp;lt;/ref&amp;gt; The first compound identified as having a δ bond was &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;[[Chemistry:Potassium octachlorodirhenate|&lt;/del&gt;potassium octachlorodirhenate(III)&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;]]&lt;/del&gt;. In 1965, F. A. Cotton reported that there was δ-bonding as part of the rhenium–rhenium &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;[[Chemistry:Quadruple bond|&lt;/del&gt;quadruple bond&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;]] &lt;/del&gt;in the [Re&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;Cl&amp;lt;sub&amp;gt;8&amp;lt;/sub&amp;gt;]&amp;lt;sup&amp;gt;2−&amp;lt;/sup&amp;gt; ion.&amp;lt;ref&amp;gt;{{cite journal|title=Metal–Metal Bonding in [Re&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;X&amp;lt;sub&amp;gt;8&amp;lt;/sub&amp;gt;]&amp;lt;sup&amp;gt;2−&amp;lt;/sup&amp;gt; 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}}&amp;lt;/ref&amp;gt; Another example of a δ bond is proposed in &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;[[Chemistry:Cyclobutadieneiron tricarbonyl|&lt;/del&gt;cyclobutadieneiron tricarbonyl&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;]] &lt;/del&gt;between an iron d orbital and the four p orbitals of the attached cyclobutadiene molecule.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;The δ notation was introduced by Robert Mulliken in 1931.&amp;lt;ref&amp;gt;{{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}}&amp;lt;/ref&amp;gt;&amp;lt;ref&amp;gt;{{cite journal|title=Bonding Power of Electrons and Theory of Valence|first=Robert S.|last=Mulliken|journal=Chem. Rev.|date=1931|volume=9|issue=3|pages=347–388|doi=10.1021/cr60034a001}}&amp;lt;/ref&amp;gt; The first compound identified as having a δ bond was potassium octachlorodirhenate(III). In 1965, F. A. Cotton reported that there was δ-bonding as part of the rhenium–rhenium quadruple bond in the [Re&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;Cl&amp;lt;sub&amp;gt;8&amp;lt;/sub&amp;gt;]&amp;lt;sup&amp;gt;2−&amp;lt;/sup&amp;gt; ion.&amp;lt;ref&amp;gt;{{cite journal|title=Metal–Metal Bonding in [Re&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;X&amp;lt;sub&amp;gt;8&amp;lt;/sub&amp;gt;]&amp;lt;sup&amp;gt;2−&amp;lt;/sup&amp;gt; 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}}&amp;lt;/ref&amp;gt; Another example of a δ bond is proposed in cyclobutadieneiron tricarbonyl between an iron d orbital and the four p orbitals of the attached cyclobutadiene molecule.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&amp;lt;/div&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&amp;lt;/div&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
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&lt;/table&gt;</summary>
		<author><name>WikiHarold</name></author>
	</entry>
	<entry>
		<id>https://handwiki.scholarlywiki.org/index.php?title=Physics:Quantum_delta_bond&amp;diff=3251&amp;oldid=prev</id>
		<title>Harold: Restore Quantum article header template</title>
		<link rel="alternate" type="text/html" href="https://handwiki.scholarlywiki.org/index.php?title=Physics:Quantum_delta_bond&amp;diff=3251&amp;oldid=prev"/>
		<updated>2026-05-17T21:51:58Z</updated>

		<summary type="html">&lt;p&gt;Restore Quantum article header template&lt;/p&gt;
&lt;table style=&quot;background-color: #fff; color: #202122;&quot; data-mw=&quot;interface&quot;&gt;
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				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;← Older revision&lt;/td&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;Revision as of 21:51, 17 May 2026&lt;/td&gt;
				&lt;/tr&gt;&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l1&quot;&gt;Line 1:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 1:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;{{Short description|Type of chemical bond}}&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;{{Short description|Type of chemical bond}}&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;[[File&lt;/del&gt;:&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;Delta&lt;/del&gt;-&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;bond&lt;/del&gt;-&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;formation&lt;/del&gt;-&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;2D&lt;/del&gt;.&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;png|thumb|right|200px|Formation of a δ bond by the overlap of two d orbitals]]&lt;/del&gt;&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt; &lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-deleted&quot;&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;{{Quantum matter backlink|Molecules}}&lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-deleted&quot;&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt; &lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
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&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-deleted&quot;&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;&amp;lt;/div&amp;gt;&lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
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&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-deleted&quot;&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;&amp;lt;div style=&quot;flex:1; line&lt;/ins&gt;-&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;height:1&lt;/ins&gt;.&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;45; color:#006b45; column-count:2; column-gap:32px; column-rule:1px solid #b8d8c8;&quot;&amp;gt;&lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;[[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 Mo&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;]]&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;[[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 Mo&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;]]&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;/tr&gt;
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&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 20:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;The δ notation was introduced by Robert Mulliken in 1931.&amp;lt;ref&amp;gt;{{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}}&amp;lt;/ref&amp;gt;&amp;lt;ref&amp;gt;{{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}}&amp;lt;/ref&amp;gt; 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 [Re&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;Cl&amp;lt;sub&amp;gt;8&amp;lt;/sub&amp;gt;]&amp;lt;sup&amp;gt;2−&amp;lt;/sup&amp;gt; ion.&amp;lt;ref&amp;gt;{{cite journal|title=Metal–Metal Bonding in [Re&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;X&amp;lt;sub&amp;gt;8&amp;lt;/sub&amp;gt;]&amp;lt;sup&amp;gt;2−&amp;lt;/sup&amp;gt; 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}}&amp;lt;/ref&amp;gt; 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.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;The δ notation was introduced by Robert Mulliken in 1931.&amp;lt;ref&amp;gt;{{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}}&amp;lt;/ref&amp;gt;&amp;lt;ref&amp;gt;{{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}}&amp;lt;/ref&amp;gt; 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 [Re&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;Cl&amp;lt;sub&amp;gt;8&amp;lt;/sub&amp;gt;]&amp;lt;sup&amp;gt;2−&amp;lt;/sup&amp;gt; ion.&amp;lt;ref&amp;gt;{{cite journal|title=Metal–Metal Bonding in [Re&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;X&amp;lt;sub&amp;gt;8&amp;lt;/sub&amp;gt;]&amp;lt;sup&amp;gt;2−&amp;lt;/sup&amp;gt; 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}}&amp;lt;/ref&amp;gt; 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.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-deleted&quot;&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;&amp;lt;/div&amp;gt;&lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-deleted&quot;&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;&lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-deleted&quot;&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;&amp;lt;div style=&quot;width:300px;&quot;&amp;gt;&lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-deleted&quot;&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;[[File:Delta-bond-formation-2D.png|thumb|280px|Formation of a δ bond by the overlap of two d orbitals]]&lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-deleted&quot;&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;&amp;lt;/div&amp;gt;&lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-deleted&quot;&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;&lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-deleted&quot;&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;&amp;lt;/div&amp;gt;&lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;== References ==&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;== References ==&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;/table&gt;</summary>
		<author><name>Harold</name></author>
	</entry>
	<entry>
		<id>https://handwiki.scholarlywiki.org/index.php?title=Physics:Quantum_delta_bond&amp;diff=811&amp;oldid=prev</id>
		<title>imported&gt;WikiHarold: WikiHarold moved page Chemistry:Delta bond to Physics:Quantum delta bond without leaving a redirect</title>
		<link rel="alternate" type="text/html" href="https://handwiki.scholarlywiki.org/index.php?title=Physics:Quantum_delta_bond&amp;diff=811&amp;oldid=prev"/>
		<updated>2026-05-04T17:10:14Z</updated>

		<summary type="html">&lt;p&gt;WikiHarold moved page &lt;a href=&quot;/index.php?title=Chemistry:Delta_bond&amp;amp;action=edit&amp;amp;redlink=1&quot; class=&quot;new&quot; title=&quot;Chemistry:Delta bond (page does not exist)&quot;&gt;Chemistry:Delta bond&lt;/a&gt; to &lt;a href=&quot;/wiki/Physics:Quantum_delta_bond&quot; title=&quot;Physics:Quantum delta bond&quot;&gt;Physics:Quantum delta bond&lt;/a&gt; without leaving a redirect&lt;/p&gt;
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				&lt;td colspan=&quot;1&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;Revision as of 17:10, 4 May 2026&lt;/td&gt;
				&lt;/tr&gt;&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-notice&quot; lang=&quot;en&quot;&gt;&lt;div class=&quot;mw-diff-empty&quot;&gt;(No difference)&lt;/div&gt;
&lt;/td&gt;&lt;/tr&gt;&lt;/table&gt;</summary>
		<author><name>imported&gt;WikiHarold</name></author>
	</entry>
	<entry>
		<id>https://handwiki.scholarlywiki.org/index.php?title=Physics:Quantum_delta_bond&amp;diff=320&amp;oldid=prev</id>
		<title>imported&gt;WikiHarold: WikiHarold moved page Chemistry:Delta bond to Physics:Quantum delta bond without leaving a redirect</title>
		<link rel="alternate" type="text/html" href="https://handwiki.scholarlywiki.org/index.php?title=Physics:Quantum_delta_bond&amp;diff=320&amp;oldid=prev"/>
		<updated>2026-05-04T17:10:14Z</updated>

		<summary type="html">&lt;p&gt;WikiHarold moved page &lt;a href=&quot;/index.php?title=Chemistry:Delta_bond&amp;amp;action=edit&amp;amp;redlink=1&quot; class=&quot;new&quot; title=&quot;Chemistry:Delta bond (page does not exist)&quot;&gt;Chemistry:Delta bond&lt;/a&gt; to &lt;a href=&quot;/wiki/Physics:Quantum_delta_bond&quot; title=&quot;Physics:Quantum delta bond&quot;&gt;Physics:Quantum delta bond&lt;/a&gt; without leaving a redirect&lt;/p&gt;
&lt;p&gt;&lt;b&gt;New page&lt;/b&gt;&lt;/p&gt;&lt;div&gt;{{Short description|Type of chemical bond}}&lt;br /&gt;
[[File:Delta-bond-formation-2D.png|thumb|right|200px|Formation of a δ bond by the overlap of two d orbitals]]&lt;br /&gt;
[[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 Mo&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;]]&lt;br /&gt;
&lt;br /&gt;
In [[HandWiki:Chemistry|chemistry]], a &amp;#039;&amp;#039;&amp;#039;delta bond&amp;#039;&amp;#039;&amp;#039; (&amp;#039;&amp;#039;&amp;#039;δ bond&amp;#039;&amp;#039;&amp;#039;) 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.&amp;lt;ref&amp;gt;{{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}}&amp;lt;/ref&amp;gt;&amp;lt;ref&amp;gt;{{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}}&amp;lt;/ref&amp;gt;&amp;lt;ref&amp;gt;{{cite book|title=Inorganic Chemistry|last=Huheey|first=J. E.|date=1983|publisher=Harper and Row|isbn=9780060429874|edition=3rd|pages=743–744}}&amp;lt;/ref&amp;gt;&amp;lt;ref&amp;gt;{{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}}&amp;lt;/ref&amp;gt;&lt;br /&gt;
&lt;br /&gt;
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 [Re&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;Cl&amp;lt;sub&amp;gt;8&amp;lt;/sub&amp;gt;]&amp;lt;sup&amp;gt;2-&amp;lt;/sup&amp;gt; ion in the D&amp;lt;sub&amp;gt;4h&amp;lt;/sub&amp;gt; [[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.&amp;lt;ref&amp;gt;{{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}}&amp;lt;/ref&amp;gt;&lt;br /&gt;
&lt;br /&gt;
[[File:Molecular orbital diagram of d orbitals in D4h Re2Cl8.jpg|thumb|Molecular Orbital Diagram of D&amp;lt;sub&amp;gt;4h&amp;lt;/sub&amp;gt; [Re&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;Cl&amp;lt;sub&amp;gt;8&amp;lt;/sub&amp;gt;&amp;lt;nowiki&amp;gt;]&amp;lt;/nowiki&amp;gt;&amp;lt;sup&amp;gt;2-&amp;lt;/sup&amp;gt; showing the bonding and antibonding d orbital interactions and their relative energies. the d&amp;lt;sub&amp;gt;x&amp;lt;/sub&amp;gt;&amp;lt;sup&amp;gt;2&amp;lt;/sup&amp;gt;&amp;lt;sub&amp;gt;-y&amp;lt;/sub&amp;gt;&amp;lt;sup&amp;gt;2&amp;lt;/sup&amp;gt; is omitted from d-d interactions due to its engagement with chloride ligands]]&lt;br /&gt;
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.&lt;br /&gt;
&lt;br /&gt;
The δ notation was introduced by Robert Mulliken in 1931.&amp;lt;ref&amp;gt;{{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}}&amp;lt;/ref&amp;gt;&amp;lt;ref&amp;gt;{{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}}&amp;lt;/ref&amp;gt; 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 [Re&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;Cl&amp;lt;sub&amp;gt;8&amp;lt;/sub&amp;gt;]&amp;lt;sup&amp;gt;2−&amp;lt;/sup&amp;gt; ion.&amp;lt;ref&amp;gt;{{cite journal|title=Metal–Metal Bonding in [Re&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;X&amp;lt;sub&amp;gt;8&amp;lt;/sub&amp;gt;]&amp;lt;sup&amp;gt;2−&amp;lt;/sup&amp;gt; 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}}&amp;lt;/ref&amp;gt; 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.&lt;br /&gt;
&lt;br /&gt;
== References ==&lt;br /&gt;
{{Reflist}}&lt;br /&gt;
&lt;br /&gt;
{{Chemical bonding theory}}&lt;br /&gt;
&lt;br /&gt;
{{DEFAULTSORT:Delta Bond}}&lt;br /&gt;
[[Category:Chemical bonding]]&lt;br /&gt;
&lt;br /&gt;
{{Sourceattribution|Delta bond}}&lt;/div&gt;</summary>
		<author><name>imported&gt;WikiHarold</name></author>
	</entry>
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