View source for Chemistry:Vanadium(III) chloride

{{chembox
| Watchedfields = changed
| verifiedrevid = 470628593
| Name = Vanadium(III) chloride
| ImageFile = VCl3 anhydrous.jpg
| ImageCaption = Anhydrous
| ImageFile1 = VCl3-layer-in-xtal-1947-3D-balls.png
| ImageSize1 = 
| ImageName1 = Plan view of a single layer in the crystal structure of vanadium(III) chloride
| IUPACName = Vanadium(III) chloride<br/>Vanadium trichloride
| OtherNames = 
|Section1={{Chembox Identifiers
| index1_label = (hexahydrate)
| CASNo = 7718-98-1
| CASNo_Ref = {{cascite|correct|CAS}}
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 10801024
| EC_number = 231-744-6
| PubChem = 62647
| RTECS = YW2800000
| UNNumber = 2475
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/3ClH.V/h3*1H;/q;;;+3/p-3
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = HQYCOEXWFMFWLR-UHFFFAOYSA-K
| InChI = 1/3ClH.V/h3*1H;/q;;;+3/p-3
| InChIKey = HQYCOEXWFMFWLR-DFZHHIFOAB
| SMILES = [V+3].[Cl-].[Cl-].[Cl-]
| SMILES1 = O.O.O.O.O.O.[Cl-].[Cl-].[Cl-].[V+3]
  }}
|Section2={{Chembox Properties
| Formula = VCl<sub>3</sub>
| MolarMass = 157.30 g/mol
| Appearance = violet crystals (anhydrous) <br> green crystals (hexahydrate)<ref name="aquo" />
| Density = 2.8 g/cm<sup>3</sup> (anhydrous) <br> 1.84 g/cm<sup>3</sup> (hexahydrate)
| Solubility = soluble
| MeltingPt= 
| MeltingPtC = 350
| MeltingPt_ref = <ref name="decomp">{{cite journal |author1=Yajima Akimasa |author2=Matsuzaki Ryoko |author3=Saeki Yuzo |title=The Thermal Decomposition of Vanadium(III) Chloride Oxide and Its Reaction with Oxygen |journal=Bulletin of the Chemical Society of Japan |date=1979 |volume=52 |issue=11 |pages=3292-3295 |doi=10.1246/bcsj.52.3292 |language=en}}</ref>
| MeltingPt_notes = (decomposes, anhydrous) 
| MagSus = +3030.0·10<sup>−6</sup> cm<sup>3</sup>/mol
  }}
|Section3={{Chembox Structure
| CrystalStruct = [[Chemistry:Trigonal|Trigonal]], [[Physics:Pearson symbol|hR24]]<ref name="crys" />
| SpaceGroup = R{{overline|3}}, No. 148<ref name="crys" />
| LattConst_a = 6.012 Å
| LattConst_b = 6.012 Å
| LattConst_c = 17.34 Å
| LattConst_alpha = 
| LattConst_beta = 
| LattConst_gamma = 120
| LattConst_ref = <ref name="crys" />
| LattConst_Comment = (anhydrous)
 }}
| Section4       = {{Chembox Thermochemistry
| Thermochemistry_ref = <ref name="crc">{{cite book |author1=John Rumble |title=CRC Handbook of Chemistry and Physics |date=June 18, 2018 |publisher=CRC Press |isbn=978-1138561632 |pages=5–40|edition=99 |language=English}}</ref>
| DeltaGf = -511.2 kJ/mol
| DeltaHc = 
| DeltaHf = -580.7 kJ/mol
| Entropy = 131.0 J mol<sup>−1</sup> K<sup>−1</sup>
| HeatCapacity = 93.2 J mol<sup>−1</sup> K<sup>−1</sup>
  }}
|Section7={{Chembox Hazards
| ExternalSDS = [https://www.americanelements.com/printpdf/vanadium-iii-chloride-7718-98-1/sds Vanadium(III) Chloride]
| GHSPictograms = {{GHS05}}{{GHS07}}
| GHS_ref = <ref name=SDS>{{cite web|title = Vanadium(III) Chloride SDS|url = https://www.americanelements.com/printpdf/vanadium-iii-chloride-7718-98-1/sds|website = American Elements|access-date = 2018-08-17}}</ref>
| GHSSignalWord = Danger
| HPhrases = {{H-phrases|302|314}}
| PPhrases = {{P-phrases|260|264|270|280|301+312+330|301+330+331|303+361+353|304+340+310|305+351+338+310|363|405|501}}
| MainHazards = 
| NFPA-H = 3
| NFPA-F = 0
| NFPA-I = 2
| NFPA-S = 
| FlashPt = Non-flammable
  }}
|Section8={{Chembox Related
| OtherAnions = [[Chemistry:Vanadium(III) fluoride|Vanadium(III) fluoride]]<br>[[Chemistry:Vanadium(III) bromide|Vanadium(III) bromide]]<br>[[Chemistry:Vanadium(III) iodide|Vanadium(III) iodide]]
| OtherCations = [[Chemistry:Titanium(III) chloride|Titanium(III) chloride]]<br>[[Chemistry:Chromium(III) chloride|Chromium(III) chloride]]<br>[[Chemistry:Niobium(III) chloride|Niobium(III) chloride]]<br>[[Chemistry:Tantalum(III) chloride|Tantalum(III) chloride]]
| OtherCompounds = [[Chemistry:Vanadium(II) chloride|Vanadium(II) chloride]]<br>[[Chemistry:Vanadium(IV) chloride|Vanadium(IV) chloride]]
  }}
}}

'''Vanadium(III) chloride'''  describes the [[Chemistry:Inorganic compound|inorganic compound]] with the [[Chemistry:Chemical formula|formula]] VCl<sub>3</sub> and its hydrates. It forms a purple anhydrous form and a green hexahydrate [VCl<sub>2</sub>(H<sub>2</sub>O)<sub>4</sub>]Cl·2H<sub>2</sub>O. These [[Physics:Hygroscopic|hygroscopic]] salts are common precursors to other vanadium(III) complexes and is used as a mild [[Chemistry:Reducing agent|reducing agent]].<ref>Holleman, A. F.; Wiberg, E. ''Inorganic Chemistry'' Academic Press: San Diego, 2001. {{ISBN|0-12-352651-5}}.</ref>

==Structure and electronic configuration==
VCl<sub>3</sub> has the common layered BiI<sub>3</sub> structure, a motif that features hexagonally closest-packed chloride framework with vanadium ions occupying the octahedral holes.<ref name=":0">{{Cite journal |last=Mastrippolito |first=Dario |last2=Camerano |first2=Luigi |last3=Świątek |first3=Hanna |last4=Šmíd |first4=Břetislav |last5=Klimczuk |first5=Tomasz |last6=Ottaviano |first6=Luca |last7=Profeta |first7=Gianni |date=2023-07-17 |title=<nowiki>Polaronic and Mott insulating phase of layered magnetic vanadium trihalide VCl3</nowiki> |url=https://link.aps.org/doi/10.1103/PhysRevB.108.045126 |journal=Physical Review B |volume=108 |issue=4 |pages=045126 |doi=10.1103/PhysRevB.108.045126|arxiv=2301.06501 }}</ref> [[Chemistry:Vanadium(III) bromide|VBr<sub>3</sub>]] and [[Chemistry:Vanadium(III) iodide|VI<sub>3</sub>]] adopt the same structure, but [[Chemistry:Vanadium(III) fluoride|VF<sub>3</sub>]] features a structure more closely related to [[Chemistry:Rhenium trioxide|ReO<sub>3</sub>]].<ref name="crys">{{cite journal |author1=Wilhelm Klemm |author2=Ehrhard Krose |title=Die Kristallstrukturen von ScCl<sub>3</sub>, TiCl<sub>3</sub> und VCl<sub>3</sub> |journal=Zeitschrift für anorganische Chemie |date=1947 |volume=253 |issue=3–4 |pages=218–225 |doi=10.1002/zaac.19472530313 |trans-title=The Crystal Structures of ScCl<sub>3</sub>, TiCl<sub>3</sub> and VCl<sub>3</sub> |language=de}}</ref> The V<sup>3+</sup>cation has a ''d''<sup>2</sup> electronic configuration with two unpaired electrons, making the compound [[Physics:Paramagnetism|paramagnetic]].<ref name="greenwood">Greenwood, N. N. and Earnshaw, A. (1997). Chemistry of the Elements (2nd Edn.), Oxford:Butterworth-Heinemann. p. 990 {{ISBN|0-7506-3365-4}}.</ref> VCl<sub>3</sub> is a [[Physics:Mott insulator|Mott insulator]] and undergoes an [[Physics:Antiferromagnetism|antiferromagnetic]] transition at low temperatures.<ref name=":0" /><ref>{{Cite journal |last=Starr |first=C. |last2=Bitter |first2=F. |last3=Kaufmann |first3=A. R. |date=1940-12-01 |title=The Magnetic Properties of the Iron Group Anhydrous Chlorides at Low Temperatures. I. Experimental |url=https://link.aps.org/doi/10.1103/PhysRev.58.977 |journal=Physical Review |volume=58 |issue=11 |pages=977–983 |doi=10.1103/PhysRev.58.977}}</ref>

Solid hexahydrate, [VCl<sub>2</sub>(H<sub>2</sub>O)<sub>4</sub>]Cl·2H<sub>2</sub>O, has a [[Physics:Monoclinic crystal system|monoclinic]] crystal structure and consists of slightly distorted octahedral ''trans''-[VCl<sub>2</sub>(H<sub>2</sub>O)<sub>4</sub>]<sup>+</sup> centers as well as chloride and two molecules of [[Physics:Water of crystallization|water of crystallization]].<ref name="VX3aq6" /><ref name="new">{{cite journal |author1=Fiona H. Fry |author2=Brenda Dougan |author3=Nichola McCann |author4=Anthony C. Willis |author5=Christopher J. Ziegler |author6=Nicola E. Brasch |title=Synthesis and X-ray structural characterization of tris(l-glycinato)vanadium(III) and trans-tetraquadichlorovanadium(III) chloride |journal=Inorganica Chimica Acta |date=2008 |volume=361 |issue=8 |pages=2321-2326 |doi=10.1016/j.ica.2007.11.025 |language=en}}</ref> The hexahydrate phase loses two [[Physics:Water of crystallization|water of crystallization]] to form the tetrahydrate if heated to 90 °C in a stream of [[Chemistry:Hydrogen chloride|hydrogen chloride]] gas.<ref name="aquo">{{cite journal |author1=Sally M. Horner |author2=S. Y. Tyree |date=1964 |title=Chloro-Aquo Complexes of Vanadium(III) |journal=Inorganic Chemistry |language=en |volume=3 |issue=8 |pages=1173–1176 |doi=10.1021/ic50018a024}}</ref>
{{multiple image
 | align = center
 | footer = 
 | image1 = VCl3-layer-in-xtal-1947-3D-balls.png
 | alt1 = 
 | caption1 = Plan view of a single layer in the crystal structure of vanadium(III) chloride
 | width1 = 217
 | image2 = VCl3-xtal-1947-3D-balls.png
 | alt2 = 
 | caption2 = Layer stacking in the crystal structure of vanadium(III) chloride
 | width2 = 200
 | image3 = Unit cell of VCl2(H2O)4 Cl·2H2O.png
 | caption3 = Unit cell of hexahydrate, featuring [VCl<sub>2</sub>(H<sub>2</sub>O)<sub>4</sub>]<sup>+</sup> centres
 | width3 = 89
}}

==Uses==
Solutions of vanadium(III) chloride in [[Chemistry:Sulfuric acid|sulfuric acid]] and [[Chemistry:Hydrochloric acid|hydrochloric acid]] are used as electrolytes in vanadium redox batteries.<ref name="ullmann">{{cite book |author1=Günter Bauer |author2=Volker Güther |author3=Hans Hess |author4=Andreas Otto |author5=Oskar Roidl |author6=Heinz Roller |author7=Siegfried Sattelberger |author8=Sven Köther-Becker |author9=Thomas Beyer |title=Vanadium and Vanadium Compounds |date=2017 |publisher=Wiley-VCH Verlag GmbH & Co. KGaA. |isbn=9783527303854 |page=16 |doi=10.1002/14356007.a27_367.pub2 |url=https://doi.org/10.1002/14356007.a27_367.pub2 |language=en}}</ref> It is also used as a mild [[Chemistry:Lewis acid|Lewis acid]] in organic synthesis. One example of such is its use as a catalyst in the cleavage of the acetonide group.<ref>{{cite journal |author1=Gowravaram Sabitha |author2=G.S. Kiran Kumar Reddy |author3=K. Bhaskar Reddy |author4=N. Mallikarjuna Reddy |author5=J.S. Yadav |title=Vanadium(III) chloride: A mild and efficient catalyst for the chemoselective deprotection of acetonides |journal=Journal of Molecular Catalysis A: Chemical |date=2005 |volume=238 |issue=1–2 |pages=229–232 |doi=10.1016/j.molcata.2005.05.028 |language=en}}</ref> Another example of the use of VCl<sub>3</sub> as a reducing agent is shown in the determination of [[Chemistry:Nitrate|nitrate]] and [[Chemistry:Nitrite|nitrite]] concentration in water, where VCl<sub>3</sub> reduces nitrate to nitrite. This method is a safer alternative to the cadmium column method.<ref>{{cite journal |author1=Bernhard Schnetger |author2=Carola Lehners |title=Determination of nitrate plus nitrite in small volume marine water samples using vanadium(III)chloride as a reduction agent |journal=Marine Chemistry |date=2014 |volume=160 |pages=91-98 |doi=10.1016/j.marchem.2014.01.010 |language=en}}</ref>

==Preparation==
VCl<sub>3</sub> is prepared by heating [[Chemistry:Vanadium tetrachloride|VCl<sub>4</sub>]] at 160–170&nbsp;°C under a flowing stream of inert gas, which sweeps out the [[Chemistry:Chlorine|Cl<sub>2</sub>]]. The bright red liquid converts to a purple solid.<ref name="prep">{{cite book |author1=Georg Brauer |title=Handbuch der präparativen anorganischen Chemie Volume 3 |date=1975 |publisher=Enke |location=the University of Michigan |page=1409 |isbn=9783432878232 |url=https://books.google.com/books?id=K9jvAAAAMAAJ |language=de}}</ref>

The vanadium oxides can also be used to produce vanadium(III) chloride. For example, [[Chemistry:Vanadium(III) oxide|vanadium(III) oxide]] reacts with [[Chemistry:Thionyl chloride|thionyl chloride]] at 200 °C:<ref name="prep" />
:V<sub>2</sub>O<sub>3</sub> + 3 SOCl<sub>2</sub> → 2 VCl<sub>3</sub> + 3 SO<sub>2</sub>
The reaction of [[Chemistry:Vanadium(V) oxide|vanadium(V) oxide]] and [[Chemistry:Disulfur dichloride|disulfur dichloride]] also produces vanadium(III) chloride with the release of [[Chemistry:Sulfur dioxide|sulfur dioxide]] and sulfur.<ref name="prep" />

The hexahydrate can be prepared by evaporation of acidic aqueous solutions of the trichloride.<ref name="aquo" />

==Reactions==
Heating of VCl<sub>3</sub> decomposes with volatilization of VCl<sub>4</sub>, leaving VCl<sub>2</sub> above 350 °C.<ref name="decomp" /><ref>{{Cite book|doi = 10.1002/9780470132357.ch43|chapter = Vanadium(III) Chloride|title = Inorganic Syntheses|year = 2007|last1 = Young|first1 = Ralph C.|last2 = Smith|first2 = Maynard E.|last3 = Moeller|first3 = Therald|last4 = Gordon|first4 = Paul G.|last5 = McCullough|first5 = Fred|pages = 128–130|isbn = 9780470132357}}</ref> Upon heating under H<sub>2</sub> at 675&nbsp;°C (but less than 700&nbsp;°C), VCl<sub>3</sub> reduces to greenish VCl<sub>2</sub>.
:: 2 VCl<sub>3</sub> + H<sub>2</sub> → 2 VCl<sub>2</sub> + 2 HCl

[[Chemistry:Comproportionation|Comproportionation]] of vanadium trichloride and vanadium(V) oxides gives [[Chemistry:Vanadium oxydichloride|vanadium oxydichloride]]:<ref>{{cite book|author=G. Brauer|chapter=Vanadium Oxydichloride|title=Handbook of Preparative Inorganic Chemistry, 2nd Ed. |editor=G. Brauer|publisher=Academic Press|year=1963|place=NY|pages=1263}}</ref>
:V<sub>2</sub>O<sub>5</sub>  +  VOCl<sub>3</sub>  +  3 VCl<sub>3</sub>  →  6 VOCl<sub>2</sub>

The heating of the hexahydrate does not give the anhydrous form, instead undergoes partial hydrolysis and forms [[Chemistry:Vanadium oxydichloride|vanadium oxydichloride]] at 160 °C. In an inert atmosphere, it forms a trihydrate at 130 °C and at higher temperatures, it forms vanadium oxychloride.<ref>{{cite book |author1=Ray Colton |author2=J. H. Canterford |title=Halides of the first row transition metals |date=1969 |publisher=Wiley |isbn=9780471166252 |page=131 |language=en}}</ref>

Vanadium trichloride catalyses the [[Chemistry:Pinacol coupling reaction|pinacol coupling reaction]] of benzaldehyde (PhCHO) to 1,2-diphenyl-1,2-ethanediol by various reducing metals such as zinc:<ref>{{Cite journal|doi = 10.1021/jo051213f|title = Vanadium-Catalyzed Pinacol Coupling Reaction in Water|year = 2005|last1 = Xu|last2 = Hirao|first2 = Toshikazu|journal = The Journal of Organic Chemistry|volume = 70|issue = 21|pages = 8594–8596|pmid = 16209617}}</ref>
:Zn + 2 H<sub>2</sub>O + 2 PhCHO → (PhCH(OH))<sub>2</sub> + Zn(OH)<sub>2</sub>

===Complexes===
VCl<sub>3</sub> forms colorful adducts and derivatives with a broad scale of ligands. VCl<sub>3</sub> dissolves in water to give the aquo complexes. From these solutions, the hexahydrate [VCl<sub>2</sub>(H<sub>2</sub>O)<sub>4</sub>]Cl<sup>.</sup>2H<sub>2</sub>O crystallizes. In other words, two of the water molecules are not bound to the vanadium, whose structure resembles the corresponding Fe(III) derivative. Removal of the two bound chloride ligands gives the green hexaaquo complex [V(H<sub>2</sub>O)<sub>6</sub>]<sup>3+</sup>.<ref name=VX3aq6>{{cite journal|doi=10.1039/DT9750000894|title=Crystal and Molecular Structures of Aquahalogenovanadium(III) Complexes. Part I. X-Ray Crystal Structure of ''trans''-Tetrakisaquadibromo-Vanadium(III) Bromide Dihydrate and the Isomorphous Chloro- Compound|year=1975|last1=Donovan|first1=William F.|last2=Smith|first2=Peter W.|journal=Journal of the Chemical Society, Dalton Transactions|issue=10|page=894}}</ref><ref name="coord" />
[[File:CSD CIF CANZOG10.png|thumb|left|152px|Structure of VCl<sub>3</sub>(thf)<sub>3</sub>.<ref>{{cite journal |year=1986|volume=113|page=81|title=Comparative Structural Studies of the First Row Early Transition Metal(III) Chloride Tetrahydrofuran Solvates|doi=10.1016/S0020-1693(00)86863-2|last1=Albert Cotton|first1=F.|last2=Duraj|first2=Stan A.|last3=Powell|first3=Gregory L.|last4=Roth|first4=Wieslaw J.|journal=Inorganica Chimica Acta}}</ref>]]

[[File:Vanadium(III) chloride solution.jpg|thumb|A solution of vanadium(III) chloride]]
With [[Chemistry:Tetrahydrofuran|tetrahydrofuran]], VCl<sub>3</sub> forms the red/pink complex VCl<sub>3</sub>(THF)<sub>3</sub>.<ref>{{cite book |doi=10.1002/9780470132524.ch31|title=Tetrahydrofuran Complexes of Selected Early Transition Metals|series=Inorganic Syntheses|year=1982|last1=Manzer|first1=L. E.|pages=135–140|volume=21}}</ref> Vanadium(III) chloride reacts with [[Chemistry:Acetonitrile|acetonitrile]] to give the green adduct VCl<sub>3</sub>(MeCN)<sub>3</sub>. When treated with KCN, VCl<sub>3</sub> converts to [V(CN)<sub>7</sub>]<sup>4−</sup> (early metals commonly adopt coordination numbers greater than 6 with compact ligands). Complementarily, larger metals can form complexes with rather bulky ligands. This aspect is illustrated by the isolation of VCl<sub>3</sub>(NMe<sub>3</sub>)<sub>2</sub>, containing two bulky NMe<sub>3</sub> ligands. Vanadium(III) chloride is able to form complexes with other adducts, such as [[Chemistry:Pyridine|pyridine]] or [[Chemistry:Triphenylphosphine oxide|triphenylphosphine oxide]].<ref name="coord">{{cite journal |author1=D. Nicholls |title=The coordination chemistry of vanadium |journal=Coordination Chemistry Reviews |date=1966 |volume=1 |issue=3 |pages=379-414 |doi=10.1016/S0010-8545(00)80145-9 |language=en}}</ref>

===Organometallic derivatives===
Vanadium(III) chloride as its thf complex is a precursor toV([[Chemistry:Mesitylene|mesityl]])<sub>3</sub>.<ref>{{Cite journal|doi=10.1021/om00029a042|title=Chemistry of the vanadium-carbon .sigma. Bond. 2. Oxovanadium(IV) and oxovanadium(V) containing metal-to-carbon .sigma. Bonds|year=1993|last1=Vivanco|first1=Marilin|last2=Ruiz|first2=Javier|last3=Floriani|first3=Carlo|last4=Chiesi-Villa|first4=Angiola|last5=Rizzoli|first5=Corrado|journal=Organometallics|volume=12|issue=5|pages=1802–1810}}</ref>
:: VCl<sub>3</sub>(THF)<sub>3</sub> + 3 LiC<sub>6</sub>H<sub>2</sub>-2,4,6-Me<sub>3</sub> → V(C<sub>6</sub>H<sub>2</sub>-2,4,6-Me<sub>3</sub>)<sub>3</sub>(THF) + 3 LiCl

==References==
{{reflist}}

{{Vanadium compounds}}
{{Chlorides}}

{{DEFAULTSORT:Vanadium(Iii) Chloride}}
[[Category:Chlorides]]
[[Category:Metal halides]]

{{Sourceattribution|Vanadium(III) chloride}}