Strontium fluoride, SrF2, also called strontium difluoride and strontium(II) fluoride, is a fluoride of strontium. It is a brittle white crystalline solid. In nature, it appears as the very rare mineral strontiofluorite.[2][3]
The solid adopts the fluorite structure. In the vapour phase the SrF2 molecule is non-linear with an F−Sr−F angle of approximately 120°.[5] This is an exception to VSEPR theory which would predict a linear structure. Ab initio calculations have been cited to propose that contributions from d orbitals in the shell below the valence shell are responsible.[6] Another proposal is that polarization of the electron core of the strontium atom creates an approximately tetrahedral distribution of charge that interacts with the Sr−F bonds.[7]
Properties
It is almost insoluble in water (its Ksp value is approximately 2.0x10−10 at 25 degrees Celsius).
It irritates eyes and skin, and is harmful when inhaled or ingested. Similar to CaF2 and BaF2, SrF2 displays superionic conductivity at elevated temperatures.[8]
^Ab initio model potential study of the equilibrium geometry of alkaline earth dihalides: MX2 (M = Mg, Ca, Sr, Ba; X=F, Cl, Br, I)Seijo L.,Barandiarán Z J. Chem. Phys. 94, 3762 (1991) doi:10.1063/1.459748
^Core Distortions and Geometries of the Difluorides and Dihydrides of Ca, Sr, and Ba Bytheway I, Gillespie RJ, Tang TH, Bader RF Inorganic Chemistry, Vol.34, No.9, 2407-2414, 1995 doi:10.1021/ic00113a023
strontium, fluoride, srf2, also, called, strontium, difluoride, strontium, fluoride, fluoride, strontium, brittle, white, crystalline, solid, nature, appears, very, rare, mineral, strontiofluorite, namesother, names, strontium, difluoridestrontium, fluorideide. Strontium fluoride SrF2 also called strontium difluoride and strontium II fluoride is a fluoride of strontium It is a brittle white crystalline solid In nature it appears as the very rare mineral strontiofluorite 2 3 Strontium fluoride NamesOther names Strontium difluorideStrontium II fluorideIdentifiersCAS Number 7783 48 4 Y3D model JSmol Interactive imageChemSpider 74190 YECHA InfoCard 100 029 091EC Number 232 00 3PubChem CID 82210UNII EFY8GJS81Z YCompTox Dashboard EPA DTXSID20894160InChI InChI 1S 2FH Sr h2 1H q 2 p 2 YKey FVRNDBHWWSPNOM UHFFFAOYSA L YInChI 1 2FH Sr h2 1H q 2 p 2Key FVRNDBHWWSPNOM NUQVWONBAOSMILES Sr 2 F F PropertiesChemical formula SrF2Molar mass 125 62 g molDensity 4 24 g cm3Melting point 1 473 C 2 683 F 1 746 K Boiling point 2 460 C 4 460 F 2 730 K Solubility in water 0 117 g 100 mLSolubility product Ksp 4 33 10 9 1 Magnetic susceptibility x 37 2 10 6 cm3 molRefractive index nD 1 439 0 58 µmStructureCrystal structure cubic crystal system cF12Space group Fm3m 225Lattice constant a 5 80 A b 5 80 A c 5 80 Aa 90 b 90 g 90 Coordination geometry Sr 8 cubicF 4 tetrahedralHazardsFlash point Non flammableRelated compoundsOther anions Strontium chlorideStrontium bromideStrontium iodideOther cations beryllium fluoridemagnesium fluoridecalcium fluoridebarium fluorideExcept where otherwise noted data are given for materials in their standard state at 25 C 77 F 100 kPa N verify what is Y N Infobox references Contents 1 Preparation 2 Structure 3 Properties 4 Uses 5 ReferencesPreparation EditStrontium fluoride is prepared by the action of hydrofluoric acid on strontium carbonate 4 Structure EditThe solid adopts the fluorite structure In the vapour phase the SrF2 molecule is non linear with an F Sr F angle of approximately 120 5 This is an exception to VSEPR theory which would predict a linear structure Ab initio calculations have been cited to propose that contributions from d orbitals in the shell below the valence shell are responsible 6 Another proposal is that polarization of the electron core of the strontium atom creates an approximately tetrahedral distribution of charge that interacts with the Sr F bonds 7 Properties EditIt is almost insoluble in water its Ksp value is approximately 2 0x10 10 at 25 degrees Celsius It irritates eyes and skin and is harmful when inhaled or ingested Similar to CaF2 and BaF2 SrF2 displays superionic conductivity at elevated temperatures 8 Strontium fluoride is transparent to light in the wavelengths from vacuum ultraviolet 150 nm to infrared 11 µm Its optical properties are intermediate to calcium fluoride and barium fluoride 9 Uses EditStrontium fluoride is used as an optical material for a small range of special applications for example as an optical coating on lenses and also as a thermoluminescent dosimeter crystal Another use is as a carrier of strontium 90 radioisotope in radioisotope thermoelectric generators References Edit John Rumble June 18 2018 CRC Handbook of Chemistry and Physics 99 ed CRC Press pp 5 189 ISBN 978 1138561632 Strontiofluorite List of Minerals 21 March 2011 W Kwasnik 1963 Strontium Fluoride In G Brauer ed Handbook of Preparative Inorganic Chemistry 2nd Ed Vol 1 NY NY Academic Press p 234 Greenwood Norman N Earnshaw Alan 1997 Chemistry of the Elements 2nd ed Butterworth Heinemann ISBN 978 0 08 037941 8 Ab initio model potential study of the equilibrium geometry of alkaline earth dihalides MX2 M Mg Ca Sr Ba X F Cl Br I Seijo L Barandiaran Z J Chem Phys 94 3762 1991 doi 10 1063 1 459748 Core Distortions and Geometries of the Difluorides and Dihydrides of Ca Sr and Ba Bytheway I Gillespie RJ Tang TH Bader RF Inorganic Chemistry Vol 34 No 9 2407 2414 1995 doi 10 1021 ic00113a023 https web archive org web 20051214052733 http www newmet co uk Products koch strontium php Mediatopia Ltd Strontium Fluoride SrF2 Optical Material Crystran co uk Retrieved 2012 08 18 Retrieved from https en wikipedia org w index php title Strontium fluoride amp oldid 1099776395, wikipedia, wiki, book, books, library,
