Editing Acetonitrile (section)

==Applications==
Acetonitrile is used mainly as a solvent in the purification of [[butadiene]] in refineries. Specifically, acetonitrile is fed into the top of a [[distillation column]] filled with [[hydrocarbon]]s including butadiene, and as the acetonitrile falls down through the column, it absorbs the butadiene which is then sent from the bottom of the tower to a second separating tower. Heat is then employed in the separating tower to separate the butadiene.

In the laboratory, it is used as a medium-polarity [[protic solvent|non-protic]] solvent that is [[Miscibility|miscible]] with water and a range of organic solvents, but not saturated hydrocarbons.  It has a convenient range of temperatures at which it is a liquid, and a high [[dielectric constant]] of 38.8. With a [[Electric dipole moment|dipole moment]] of 3.92&nbsp;[[Debye|D]],<ref>{{cite journal|last1=Steiner|first1=P.&nbsp;A.|last2=Gordy|first2=W.|date=1966|title=Journal of Molecular Spectroscopy|url=http://www.sciencedirect.com/science/journal/00222852/21|volume=21|page=291}}</ref> acetonitrile dissolves a wide range of ionic and nonpolar compounds and is useful as a mobile phase in [[High-performance liquid chromatography|HPLC]] and [[Liquid chromatography–mass spectrometry|LC–MS]].

It is widely used in [[Battery (electricity)|battery]] applications because of its relatively high dielectric constant and ability to dissolve [[electrolyte]]s.  For similar reasons, it is a popular solvent in [[cyclic voltammetry]].

Its ultraviolet transparency [[UV cutoff]], low [[viscosity]] and low [[chemical reactivity]] make it a popular choice for [[high-performance liquid chromatography]] (HPLC).

Acetonitrile plays a significant role as the dominant solvent used in [[oligonucleotide synthesis]] from [[nucleoside phosphoramidite]]s.

Industrially, it is used as a solvent for the manufacture of [[pharmaceutical]]s and [[photographic film]].<ref name="ecb"/>

===Organic synthesis===
Acetonitrile is a common two-carbon building block in [[organic synthesis]]<ref>{{OrgSynth | last1= DiBiase |first1=S.&nbsp;A. |last2=Beadle |first2=J.&nbsp;R. |last3=Gokel |first3=G.&nbsp;W. | title = Synthesis of α,β-Unsaturated Nitriles from Acetonitrile: Cyclohexylideneacetonitrile and Cinnamonitrile | collvol = 7 | collvolpages = 108 | prep = cv7p0108}}</ref> of many useful chemicals, including [[acetamidine hydrochloride]], [[thiamine]], and [[1-naphthaleneacetic acid]].<ref name="encyc-toxic">{{Citation|title=Encyclopedia of Toxicology|editor=Philip Wexler|publisher=Elsevier|year=2005|edition=2nd|volume=1|isbn=0-12-745354-7|pages=28–30}}</ref> Its reaction with [[cyanogen chloride]] affords [[malononitrile]].<ref name = "ashford" />

===As an electron pair donor===
Acetonitrile has a free electron pair at the nitrogen atom, which can form many [[transition metal nitrile complexes]]. Being weakly basic, it is an easily displaceable [[ligand]]. For example, [[bis(acetonitrile)palladium dichloride]] is prepared by heating a suspension of [[palladium chloride]] in acetonitrile:<ref>{{Cite book|title=Organic synthesis : concepts and methods|last=Jürgen-Hinrich.|first=Fuhrhop|date=2003|publisher=Wiley-VCH|others=Li, Guangtao, Dr.|isbn=9783527302727|edition=3rd, completely rev. and enl.|location=Weinheim|oclc=51068223|page=26}}</ref>
:{{chem2|PdCl2 + 2 CH3CN -> PdCl2(CH3CN)2}}
A related complex is [[tetrakis(acetonitrile)copper(I) hexafluorophosphate]] {{chem2|[Cu(CH3CN)4]+}}. The {{chem2|CH3CN}} groups in these complexes are rapidly displaced by many other ligands.

It also forms Lewis adducts with group 13 [[Lewis acid]]s like [[boron trifluoride]].<ref>B. Swanson, D. F. Shriver, J. A. Ibers, "Nature of the donor-acceptor bond in acetonitrile-boron trihalides. The structures of the boron trifluoride and boron trichloride complexes of acetonitrile", Inorg. Chem., 2969., volume 8, pp. 2182-2189, {{doi:10.1021/ic50080a032}}</ref> In [[superacid]]s, it is possible to protonate acetonitrile.<ref name="Christe">{{cite journal|last1 = Haiges|first1=Ralf|last2=Baxter|first2=Amanda F.|last3=Goetz|first3=Nadine R.|last4=Axhausen|first4=Joachim A.|last5=Soltner|first5=Theresa|last6=Kornath|first6=Andreas|last7=Christe|first7=Kalr O.|title=Protonation of nitriles: isolation and characterization of alkyl- and arylnitrilium ions|journal=Dalton Transactions|year=2016|volume=45|issue=20|pages=8494–8499|doi=10.1039/C6DT01301E|pmid=27116374}}</ref>