Titanium tetrafluoride

{{chembox | verifiedrevid = 401635842 | Name = Titanium(IV) fluoride | ImageFile = Titanium(IV)-fluoride-from-xtal-column-3D-bs-17.png | ImageClass = bg-transparent | ImageSize = 160px | ImageName = Titanium(IV) fluoride | IUPACName = Titanium(IV) fluoride | OtherNames = Titanium tetrafluoride |Section1={{Chembox Identifiers | ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}} | ChemSpiderID = 7988529 | InChI = 1/4FH.Ti/h4*1H;/q;;;;+4/p-4 | InChIKey = XROWMBWRMNHXMF-XBHQNQODAM | SMILES = F[Ti](F)(F)F | StdInChI_Ref = {{stdinchicite|correct|chemspider}} | StdInChI = 1S/4FH.Ti/h4*1H;/q;;;;+4/p-4 | StdInChIKey_Ref = {{stdinchicite|correct|chemspider}} | StdInChIKey = XROWMBWRMNHXMF-UHFFFAOYSA-J | CASNo = 7783-63-3 | CASNo_Ref = {{cascite|correct|CAS}} | UNII_Ref = {{fdacite|correct|FDA}} | UNII = T08RW8YRG1 | PubChem = 121824 | EINECS = 232-017-6 }} |Section2={{Chembox Properties | Formula = TiF₄ | MolarMass = 123.861 g/mol | Appearance = white powder | Density = 2.798 g/cm³ | MeltingPtC = 377 | BoilingPt = sublimes }} |Section7={{Chembox Hazards | GHS_ref=<ref>{{cite web |title=Titanium tetrafluoride |url=https://pubchem.ncbi.nlm.nih.gov/compound/121824#section=Safety-and-Hazards |website=pubchem.ncbi.nlm.nih.gov |access-date=12 December 2021 |language=en}}</ref> | GHSPictograms = {{GHS05}}{{GHS07}} | GHSSignalWord = Danger | HPhrases = {{H-phrases|302|312|314|332}} | PPhrases = {{P-phrases|260|261|264|270|271|280|301+312|301+330+331|302+352|303+361+353|304+312|304+340|305+351+338|310|312|322|330|363|405}} | NFPA-H = 3 | NFPA-F = 0 | NFPA-R = 0 }} |Section8={{Chembox Related | OtherAnions = Titanium(IV) bromide <br/> Titanium(IV) chloride <br/> Titanium(IV) iodide | OtherCompounds = Titanium(III) fluoride }} }}

'''Titanium(IV) fluoride''' is the inorganic compound with the formula TiF₄. It is a white hygroscopic solid. In contrast to the other tetrahalides of titanium, it adopts a polymeric structure.<ref>{{Greenwood&Earnshaw2nd}}</ref> In common with the other tetrahalides, TiF₄ is a strong Lewis acid.

==Preparation and structure== The traditional method involves treatment of titanium tetrachloride with excess hydrogen fluoride:<ref name=KO>{{cite book |doi=10.1002/0471238961.2009200113051908.a01 |chapter=Fluorine Compounds, Inorganic, Titanium |title=Kirk-Othmer Encyclopedia of Chemical Technology |year=2000 |last1=Meshri |first1=Dayal T. |isbn=978-0-471-48494-3 }}</ref> :TiCl₄ + 4 HF → TiF₄ + 4 HCl Purification is by sublimation, which involves reversible cracking of the polymeric structure.<ref>Handbook of Preparative Inorganic Chemistry, 2nd Ed. Edited by G. Brauer, Academic Press, 1963, NY. Vol. 1. p. 200.</ref> X-ray crystallography reveals that the Ti centres are octahedral, but conjoined in an unusual columnar structure.<ref>{{cite journal|author1=Bialowons, H.|author2=Mueller, M.|author3=Mueller, B.G.|title=Titantetrafluorid - Eine Überraschend einfache Kolumnarstruktur|journal=Zeitschrift für Anorganische und Allgemeine Chemie|year=1995|volume= 621|issue=7 |pages=1227–1231|doi=10.1002/zaac.19956210720}}</ref>

==Reactions== [[File:CSD CIF AJAZAN.jpg|thumb|Structure of the [Ti₄F₁₈]^2- dianion|left]] TiF₄ forms adducts with many ligands. One example is the complex ''cis''-TiF₄(CH₃CN)₂, which is formed by treatment with acetonitrile.<ref>{{cite journal|title=A survey of Titanium Fluoride Complexes, Their Preparation, Reactivity, and Applications|author1=Nikiforov, Grigory B.|author2=Roesky, Herbert W.|author3=Koley, Debasis|journal=Coordination Chemistry Reviews |year=2014|volume=258-259|pages=16–57|doi=10.1016/j.ccr.2013.09.002|url=https://resolver.sub.uni-goettingen.de/purl?gro-2/35063|doi-access=free}}</ref> It is also used as a reagent in the preparation of organofluorine compounds.<ref>{{cite book |doi=10.1002/047084289X.rn00123.pub2 |chapter=Titanium(IV) Fluoride |title=Encyclopedia of Reagents for Organic Synthesis |year=2014 |last1=Blizzard |first1=T. A. |last2=Sikervar |first2=Vikas |pages=1–5 |isbn=978-0-470-84289-8 }}</ref> With fluoride, the cluster [Ti₄F₁₈]^2- forms. It has an adamantane-like Ti₄F₆ core.<ref>{{cite journal |doi=10.1021/ic9009338 |title=Poly&#91;perfluorotitanate(IV)&#93; Salts of &#91;H₃O&#93;⁺, Cs⁺, &#91;Me₄N&#93;⁺, and &#91;Ph₄P&#93;⁺ and about the Existence of an Isolated &#91;Ti₂F₉&#93;⁻ Anion in the Solid State |year=2009 |last1=Mazej |first1=Zoran |last2=Goreshnik |first2=Evgeny |journal=Inorganic Chemistry |volume=48 |issue=14 |pages=6918–6923 |pmid=19545141 }}</ref>

Related to its Lewis acidity, TiF₄ forms a variety of hexafluorides also called hexafluorotitanates. Hexafluorotitanic acid has been used commercially to clean metal surfaces. These salts are stable at pH<4 in the presence of hydrogen fluoride, otherwise they hydrolyze to give oxides.<ref name=KO/>

==References== {{reflist}}

{{Titanium compounds}} {{fluorides}}

Category:Fluorides Category:Titanium halides Category:Titanium(IV) compounds Category:Adamantane-like molecules