Lithium fluoride

Lithium fluoride
	; __Li+ __ F−
Names
	IUPAC name Lithium fluoride
Identifiers
CAS Number	7789-24-4 ;
3D model (JSmol)	Interactive image;
ChemSpider	23007 ;
ECHA InfoCard	100.029.229
EC Number	232-152-0;
PubChem CID	224478;
RTECS number	OJ6125000;
UNII	1485XST65B ;
CompTox Dashboard (EPA)	DTXSID10894119 ;
	show InChI
	show SMILES
Properties
Chemical formula	LiF
Molar mass	25.939(2) g/mol
Appearance	white powder or transparent crystals,; hygroscopic
Density	2.635 g/cm3
Melting point	845 °C (1,553 °F; 1,118 K)
Boiling point	1,676 °C (3,049 °F; 1,949 K)
Solubility in water	0.127 g/100 mL (18 °C); 0.134 g/100 mL (25 °C)
Solubility product (Ksp)	1.84×10−3
Solubility	soluble in HF ; insoluble in alcohol
Magnetic susceptibility (χ)	−10.1·10−6 cm3/mol
Refractive index (nD)	1.3915
Structure
Crystal structure	Face-centered cubic
Lattice constant	a = 403.51 pm
Molecular shape	Linear
Thermochemistry
Heat capacity (C)	1.507J/(g K)
Std molar; entropy (So298)	35.73 J/(mol·K)
Std enthalpy of; formation (ΔfH⦵298)	-616 kJ/mol
Hazards
GHS pictograms
GHS Signal word	Danger
GHS hazard statements	H301, H315, H319, H335
NFPA 704 (fire diamond)	3 0 0
	Lethal dose or concentration (LD, LC):
LD50 (median dose)	143 mg/kg (oral, rat)
Related compounds
Other anions	Lithium chloride; Lithium bromide; Lithium iodide;
Other cations	Sodium fluoride; Potassium fluoride; Rubidium fluoride; Caesium fluoride; Francium fluoride
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
	(what is ?)
	Infobox references

Lithium fluoride is an inorganic compound with the chemical formula LiF. It is a colorless solid, that transitions to white with decreasing crystal size. Although odorless, lithium fluoride has a bitter-saline taste. Its structure is analogous to that of sodium chloride, but it is much less soluble in water. It is mainly used as a component of molten salts.^[4] Formation of LiF from the elements releases one of the highest energy per mass of reactants, second only to that of BeO.

Manufacturing[]

LiF is prepared from lithium hydroxide or lithium carbonate with hydrogen fluoride.^[5]

Applications[]

Precursor to LiPF₆ for batteries[]

Lithium fluoride is reacted with and phosphorus pentachloride to make lithium hexafluorophosphate, an ingredient in lithium ion battery electrolyte.

In molten salts[]

Fluorine is produced by the electrolysis of molten potassium bifluoride. This electrolysis proceeds more efficiently when the electrolyte contains a few percent of LiF, possibly because it facilitates formation of an Li-C-F interface on the carbon electrodes.^[4] A useful molten salt, FLiNaK, consists of a mixture of LiF, together with sodium fluoride and potassium fluoride. The primary coolant for the Molten-Salt Reactor Experiment was FLiBe; LiF-BeF₂ (66-33 mol%).

Optics[]

Because of the large band gap for LiF, its crystals are transparent to short wavelength ultraviolet radiation, more so than any other material. LiF is therefore used in specialized optics for the vacuum ultraviolet spectrum,^[6] (See also magnesium fluoride). Lithium fluoride is used also as a diffracting crystal in X-ray spectrometry.

Radiation detectors[]

It is also used as a means to record ionizing radiation exposure from gamma rays, beta particles, and neutrons (indirectly, using the ⁶
₃Li
(n,alpha) nuclear reaction) in thermoluminescent dosimeters. ⁶LiF nanopowder enriched to 96% has been used as the neutron reactive backfill material for microstructured semiconductor neutron detectors (MSND).^[7]

Nuclear reactors[]

Lithium fluoride (highly enriched in the common isotope lithium-7) forms the basic constituent of the preferred fluoride salt mixture used in liquid-fluoride nuclear reactors. Typically lithium fluoride is mixed with beryllium fluoride to form a base solvent (FLiBe), into which fluorides of uranium and thorium are introduced. Lithium fluoride is exceptionally chemically stable and LiF/BeF₂ mixtures (FLiBe) have low melting points (360 to 459 °C or 680 to 858 °F) and the best neutronic properties of fluoride salt combinations appropriate for reactor use. MSRE used two different mixtures in the two cooling circuits.

Cathode for PLED and OLEDs[]

Lithium fluoride is widely used in PLED and OLED as a coupling layer to enhance electron injection. The thickness of the LiF layer is usually around 1 nm. The dielectric constant (or relative permittivity) of LiF is 9.0.^[8]

Natural occurrence[]

Naturally occurring lithium fluoride is known as the extremely rare mineral griceite.^[9]

References[]

^ John Rumble (June 18, 2018). CRC Handbook of Chemistry and Physics (99 ed.). CRC Press. pp. 5–188. ISBN 1138561630.
^ "Lithium fluoride - Product Specification Sheet". Sigma-Aldrich. Merck KGaA. Retrieved 1 Sep 2019.
^ "Lithium fluoride". Toxnet. NLM. Archived from the original on 12 August 2014. Retrieved 10 Aug 2014.
^ Jump up to: ^a ^b Aigueperse J, Mollard P, Devilliers D, et al. (2005). "Fluorine Compounds, Inorganic". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a11_307. ISBN 9783527303854.
^ Bellinger SL, Fronk RG, McNeil WJ, et al. (2012). "Improved High Efficiency Stacked Microstructured Neutron Detectors Backfilled With Nanoparticle ⁶LiF". IEEE Trans. Nucl. Sci. 59 (1): 167–173. doi:10.1109/TNS.2011.2175749. S2CID 19657691.
^ "Lithium Fluoride (LiF) Optical Material". Crystran 19. 2012.
^ McGregor DS, Bellinger SL, Shultis JK (2013). "Present status of microstructured semiconductor neutron detectors". Journal of Crystal Growth. 379: 99–110. doi:10.1016/j.jcrysgro.2012.10.061. hdl:2097/16983.
^ Andeen C, Fontanella J, Schuele D (1970). "Low-Frequency Dielectric Constant of LiF, NaF, NaCl, NaBr, KCl, and KBr by the Method of Substitution". Phys. Rev. B. 2 (12): 5068–73. doi:10.1103/PhysRevB.2.5068.
^ "Griceite mineral information and data". Mindat.org. Archived from the original on 7 March 2014. Retrieved 22 Jan 2014.

[crc-1] John Rumble (June 18, 2018). CRC Handbook of Chemistry and Physics (99 ed.). CRC Press. pp. 5–188. ISBN 1138561630.

[2] "Lithium fluoride - Product Specification Sheet". Sigma-Aldrich. Merck KGaA. Retrieved 1 Sep 2019.

[3] "Lithium fluoride". Toxnet. NLM. Archived from the original on 12 August 2014. Retrieved 10 Aug 2014.

[Aigs-4] Jump up to: ^a ^b Aigueperse J, Mollard P, Devilliers D, et al. (2005). "Fluorine Compounds, Inorganic". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a11_307. ISBN 9783527303854.

[5] Bellinger SL, Fronk RG, McNeil WJ, et al. (2012). "Improved High Efficiency Stacked Microstructured Neutron Detectors Backfilled With Nanoparticle ⁶LiF". IEEE Trans. Nucl. Sci. 59 (1): 167–173. doi:10.1109/TNS.2011.2175749. S2CID 19657691.

[crystran.co.uk-6] "Lithium Fluoride (LiF) Optical Material". Crystran 19. 2012.

[7] McGregor DS, Bellinger SL, Shultis JK (2013). "Present status of microstructured semiconductor neutron detectors". Journal of Crystal Growth. 379: 99–110. doi:10.1016/j.jcrysgro.2012.10.061. hdl:2097/16983.

[8] Andeen C, Fontanella J, Schuele D (1970). "Low-Frequency Dielectric Constant of LiF, NaF, NaCl, NaBr, KCl, and KBr by the Method of Substitution". Phys. Rev. B. 2 (12): 5068–73. doi:10.1103/PhysRevB.2.5068.

[9] "Griceite mineral information and data". Mindat.org. Archived from the original on 7 March 2014. Retrieved 22 Jan 2014.

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show v t Lithium compounds
Inorganic	CsLiB₆O₁₀ CLBO Li₂ Dilithium LiAlCl₄ Tetrachloroaluminate Li_1+xAl_xGe_2-x(PO₄)₃ LAGP/LAGPO LiAlH₄ Aluminium hydride LiAlO₂ Aluminate LiB(C₆F₅)₄ Tetrakis(pentafluorophenyl)borate LiBF₄ Tetrafluoroborate LiBH₄ Borohydride LiBO₂ Metaborate LiB₃O₅ Triborate Li₂B₄O₇ Borate/Tetraborate LiBr Bromide Li₂C₂ Carbide LiCF₃SO₃ Triflate LiCH₃O Methoxide LiCN Cyanide Li₂CO₃ Carbonate Li₂C₂O₄ Oxalate LiCl Chloride LiClO Hypochlorite LiClO₃ Chlorate LiClO₄ Perchlorate LiCoO₂ Oxide LiF Fluoride FLiBe FLiNaK LiFePO₄ Iron phosphate/LFP LiGaH₄ Tetrahydridogallate Li₂GeF₆ Hexafluorogermanate LiH Hydride LiHCO₃ Bicarbonate LiHe Helium LiI Iodide LiIO₃ Iodate Li₂IrO₃ Iridate Li₇La₃Zr₂O₁₂ Lanthanum zirconium oxide Li₂MoO₄ Molybdate Li_0.9Mo₆O₁₇ LiN₃ Azide Li₃N Nitride LiNH₂ Amide Li₂NH Imide LiNO₂ Nitrite LiNO₃ Nitrate LiNbO₃ Niobate LiO⁻ Monoxide LiO₂ Superoxide Li₂O Oxide Li₂O₂ Peroxide LiOH Hydroxide LiPF₆ Hexafluorophosphate Li₂Po Polonide Li₂PtO₃ Platinate Li₂RuO₃ Ruthenate Li₂S Sulfide Li₂SO₃ Sulfite Li₂SO₄ Sulfate Li₂Se Selenide Li₄SiO₄ Orthosilicate Li₂SiO₃ Metasilicate Li₂Si₂O₅ Disilicate LiTaO₃ Tantalate Li₂TiO₃ Titanate Li₂WO₄ Tungstate LiYF₄ Fluoride Neodymium-doped
Organic	Hemolithin (extraterrestrial protein) Organolithium reagents Gilman reagent CH₃COOLi Acetate C₄H₆LiNO₄ Aspartate LiC₂F₆NO₄S₂ LiTFSI LiN(SiMe₃)₂ LiHMDS Li₃C₆H₅O₇ Citrate C₅H₅Li Cyclopentadienide LiN(C₃H₇)₂ Diisopropylamide (C₆H₅)₂PLi Diphenylphosphide C₁₈H₃₅LiO₃ 12-Hydroxystearate C₆H₁₃Li n-Hexyllithium C₄H₉Li n-Butyllithium CH₃CHLiCH₂CH₃ sec-Butyllithium (CH₃)₃CLi tert-Butyllithium C₁₂H₂₈BLi L-selectride CH₃Li Methyllithium Li⁺C₁₀H₈⁻ Naphthalene C₅H₁₁Li Neopentyllithium C₅H₃LiN₂O₄ Orotate C₆H₅Li Phenyllithium LiC₂CH₃ Propynyllithium LiO₂C(CH₂)₁₆CH₃ Stearate C₄H₅LiO₄ Succinate LiEt₃BH Superhydride LiOC(CH₃)₃ tert-Butoxide C₉H₁₈LiN Tetramethylpiperidide LiC₂H₃ Vinyllithium
Minerals	Amblygonite Elbaite Eucryptite LiAlSiO₄ Faizievite Fluor-liddicoatite Hectorite Jadarite LiNaSiB₃O₇OH Lepidolite Lithiophilite LiMnPO₄ Lithiophosphate Li₃PO₄ Nambulite Neptunite Petalite LiAlSi₄0₁₀ Pezzottaite Cs(Be₂Li)Al₂Si₆O₁₈ Saliotite Spodumene LiAl(SiO₃)₂ Sugilite Tourmaline Triphylite LiFePO₄ Zabuyelite Li₂CO₃ Zektzerite Zinnwaldite
Hypothetical	Lithium beryllide Li_xBe_y
Miscellaneous	Aluminium–lithium alloys Heteroatom-promoted lateral lithiation LB buffer Lithium nickel cobalt aluminium oxides LiNi_xCo_yAl_zO₂ Lithium nickel manganese cobalt oxides LiNi_xMn_yCo_zO₂ Lithium soap Lucifer yellow Magnesium–lithium alloys NASICON

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Names


__Li⁺ __ F⁻
IUPAC name Lithium fluoride
Identifiers
CAS Number	7789-24-4^Y
3D model (JSmol)	Interactive image
ChemSpider	23007^Y
ECHA InfoCard	100.029.229
EC Number	232-152-0
PubChem CID	224478
RTECS number	OJ6125000
UNII	1485XST65B^Y
CompTox Dashboard (EPA)	DTXSID10894119
show InChI InChI=1S/FH.Li/h1H;/q;+1/p-1^Y Key: PQXKHYXIUOZZFA-UHFFFAOYSA-M^Y InChI=1/FH.Li/h1H;/q;+1/p-1 Key: PQXKHYXIUOZZFA-REWHXWOFAG
show SMILES [Li+].[F-]
Properties
Chemical formula	LiF
Molar mass	25.939(2) g/mol
Appearance	white powder or transparent crystals, hygroscopic
Density	2.635 g/cm³
Melting point	845 °C (1,553 °F; 1,118 K)
Boiling point	1,676 °C (3,049 °F; 1,949 K)
Solubility in water	0.127 g/100 mL (18 °C) 0.134 g/100 mL (25 °C)
Solubility product (K_sp)	1.84×10⁻³^[1]
Solubility	soluble in HF insoluble in alcohol
Magnetic susceptibility (χ)	−10.1·10⁻⁶ cm³/mol
Refractive index (n_D)	1.3915
Structure
Crystal structure	Face-centered cubic
Lattice constant	a = 403.51 pm
Molecular shape	Linear
Thermochemistry
Heat capacity (C)	1.507J/(g K)
Std molar entropy (S^o₂₉₈)	35.73 J/(mol·K)
Std enthalpy of formation (Δ_fH^⦵₂₉₈)	-616 kJ/mol
Hazards
GHS pictograms
GHS Signal word	Danger
GHS hazard statements	H301, H315, H319, H335^[2]
NFPA 704 (fire diamond)	3 0 0
Lethal dose or concentration (LD, LC):
LD₅₀ (median dose)	143 mg/kg (oral, rat)^[3]
Related compounds
Other anions	Lithium chloride Lithium bromide Lithium iodide
Other cations	Sodium fluoride Potassium fluoride Rubidium fluoride Caesium fluoride Francium fluoride
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Y (what is ^YN ?)
Infobox references