Editing Nitration (section)

==Aromatic nitration==
Typical nitrations of aromatic compounds rely on a reagent called "mixed acid", a mixture of concentrated [[nitric acid]] and [[sulfuric acid]]s.<ref>John McMurry Organic Chemistry 2nd Ed.</ref><ref name="Booth"/> This mixture produces the [[nitronium ion]] (NO<sub>2</sub><sup>+</sup>), which is the active species in '''aromatic nitration'''. This active ingredient, which can be isolated in the case of [[nitronium tetrafluoroborate]],<ref>{{OrgSynth | title = Benzonitrile, 2-methyl-3,5-dinitro- | author = [[George A. Olah]] and Stephen J. Kuhn | collvol = 5 | collvolpages = 480 | prep=cv5p0480}}</ref> also effects nitration without the need for the mixed acid. In mixed-acid syntheses sulfuric acid is not consumed and hence acts as a [[catalyst]] as well as an absorbent for water.  In the case of nitration of [[benzene]], the reaction is conducted at a warm temperature, not exceeding 50&nbsp;°C.<ref>{{Cite web|url=https://www.chemguide.co.uk/organicprops/arenes/nitration.html|title=Nitration of benzene and methylbenzene}}</ref> The process is one example of [[electrophilic aromatic substitution]], which involves the attack by the electron-rich [[benzene]] ring:

:[[Image:AromaticNitrationMechanism.svg|Aromatic nitration mechanism]]

Alternative mechanisms have also been proposed, including one involving [[single electron transfer]] (SET).<ref>{{cite journal | title = Unified Mechanism Concept of Electrophilic Aromatic Nitration Revisited: Convergence of Computational Results and Experimental Data |author1=Esteves, P. M. |author2=Carneiro, J. W. M. |author3=Cardoso, S. P. |author4=Barbosa, A. G. H. |author5=Laali, K. K. |author6=Rasul, G. |author7=Prakash, G. K. S. |author8=e Olah, G. A. | journal = [[J. Am. Chem. Soc.]] | year = 2003 | doi = 10.1021/ja021307w | volume = 125 | pages = 4836–49 | pmid = 12696903 | issue = 16}}</ref><ref>{{cite journal | title = Electrophilic Aromatic Nitration: Understanding Its Mechanism and Substituent Effects |author1=Queiroz, J. F. |author2=Carneiro, J. W. M. |author3=Sabino A. A. |author4=Sparapan, R. |author5=Eberlin, M. N. |author6=Esteves, P. M. | journal = [[J. Org. Chem.]] | doi = 10.1021/jo0609475 | year = 2006 | volume = 71 | pages = 6192–203 | pmid = 16872205 | issue = 16}}</ref>