hydrogen atom abstraction
{{Short description|Any chemical reaction which swaps a hydrogen radical between two molecules}}
In chemistry, hydrogen atom abstraction, or hydrogen atom transfer (HAT), refers to a class of chemical reactions where a hydrogen free radical (a neutral hydrogen atom) is removed from a substrate with another molecule. This process follows the general equation:
:
HAT reactions are common in various redox reactions, hydrocarbon combustion, and interactions involving cytochrome P450 that contain an Fe(V)O unit. The entity removing the hydrogen atom, known as the abstractor ({{Chem2|X•}}), is often a radical itself, though in some instances, it may be a species with a closed electron shell, such as chromyl chloride. Hydrogen atom transfer can occur via a mechanism known as proton-coupled electron transfer. An illustrative synthetic instance of HAT is observed in iron zeolites, which facilitate the stabilization of alpha-oxygen.{{Cite journal|last1=Snyder|first1=Benjamin E. R.|last2=Vanelderen|first2=Pieter|last3=Bols|first3=Max L.|last4=Hallaert|first4=Simon D.|last5=Böttger|first5=Lars H.|last6=Ungur|first6=Liviu|last7=Pierloot|first7=Kristine|last8=Schoonheydt|first8=Robert A.|last9=Sels|first9=Bert F.|title=The active site of low-temperature methane hydroxylation in iron-containing zeolites|journal=Nature|language=En|volume=536|issue=7616|pages=317–321|doi=10.1038/nature19059|pmid=27535535|issn=0028-0836|bibcode=2016Natur.536..317S|date=August 2016|s2cid=4467834 }}{{Cite journal|last1=Snyder|first1=Benjamin E. R.|last2=Bols|first2=Max L.|last3=Schoonheydt|first3=Robert A.|last4=Sels|first4=Bert F.|last5=Solomon|first5=Edward I.|date=2017-12-19|title=Iron and Copper Active Sites in Zeolites and Their Correlation to Metalloenzymes|journal=Chemical Reviews|language=en|volume=118|issue=5|pages=2718–2768|doi=10.1021/acs.chemrev.7b00344|pmid=29256242|issn=0009-2665|url=https://lirias.kuleuven.be/handle/123456789/627682 }}