Tellurium tetrafluoride 4219070 189006461 2008-02-04T11:36:35Z Axiosaurus 3399137 corrected reference to Te2F10 and corrected words on other tellurium fluorides added chem box {{Chembox new | ImageFile = | ImageSize = | IUPACName = tellurium(IV) fluoride | OtherNames = | Section1 = {{Chembox Identifiers | CASNo = 15192-26-4 | PubChem = | SMILES = }} | Section2 = {{Chembox Properties | Formula = TeF<sub>4</sub> | MolarMass = 203.594 | Appearance = white crystalline solid | Density = | MeltingPt = 130 °C | BoilingPt = | Solubility = }} | Section3 = {{Chembox Hazards | MainHazards = | FlashPt = | Autoignition = }} }} '''Tellurium tetrafluoride''', TeF<sub>4</sub>, is a stable, white, hygroscopic crystalline solid and is one of two fluorides of [[tellurium]]. The other binary fluoride is [[tellurium hexafluoride]]<ref name = "Wiberg">''Inorganic Chemistry'',Egon Wiberg, Arnold Frederick Holleman Elsevier 2001 ISBN 0123526515</ref>. The widely reported [[ditellurium decafluoride|Te<sub>2</sub>F<sub>10</sub>]] has been shown to be F<sub>5</sub>TeOTeF<sub>5</sub> <ref name = "Wiberg"/> There are other tellurium compounds that contain fluorine, but only the two mentioned contain solely tellurium and fluorine. Tellurium difluoride, TeF<sub>2</sub>, and ditellurium fluoride, Te<sub>2</sub>F are not known.<ref name = "Wiberg"/> ==Preparation== Tellurium tetrafluoride can be prepared by the following reaction:<br><br> [[tellurium dioxide|TeO<sub>2</sub>]] + 2[[sulfur tetrafluoride|SF<sub>4</sub>]] → TeF<sub>4</sub> + 2[[thionyl fluoride|SOF<sub>2</sub>]] <br><br> It is also prepared by reacting [[nitryl fluoride]] with tellurium or from the elements at 0 °C or by reacting [[selenium tetrafluoride]] with [[tellurium dioxide]] at 80 °C.<br> Fluorine in nitrogen can react with [[tellurium dichloride|TeCl<sub>2</sub>]] or [[tellurium dibromide|TeBr<sub>2</sub>]] to form TeF<sub>4</sub>. [[lead(II) fluoride|PbF<sub>2</sub>]] will also fluorinate tellurium to TeF<sub>4</sub>. ==Reactivity== Tellurium tetrafluoride will react with [[water]] or [[silica]] and forms tellurium oxides. [[Copper]], [[silver]], [[gold]] or [[nickel]] will react with tellurium tetrafluoride at 185 °C. It does not react with [[platinum]]. It is soluble in [[antimony pentafluoride|SbF<sub>5</sub>]] and will precipitate out the complex TeF<sub>4</sub>SbF<sub>5</sub>. ==Properties== Tellurium tetrafluoride melts at 130 °C and decomposes to [[tellurium hexafluoride]] at 194 °C. In the solid phase it consists of infinite chains of TeF<sub>3</sub>F<sub>2/2</sub> in an octahedral geometry. A lone pair of electrons occupies the sixth position. ==References== *R.B. King; ''Inorganic Chemistry of Main Group Elements'', VCH Publishers, New York, 1995. *W.C. Cooper; ''Tellurium'', VanNostrand Reinhold Company, New York, 1971. <references/> [[Category:Tellurium compounds]] [[Category:Fluorides]]