Lithium iodide

Crystal structure
	__ Li + __ I -
Crystal system	cubic
Space group	Fm 3 m (No. 225)
Coordination numbers	Li [6], I [6]
General
Surname	Lithium iodide
other names	Lithium iodide
Ratio formula	LiI
Brief description	white, odorless solid
External identifiers / databases
EC number	233-822-5
ECHA InfoCard	100.030.735
PubChem	66321
Wikidata	Q79566
properties
Molar mass	133.85 g mol −1
Physical state	firmly
density	3.49 g cm −3 (25 ° C)
Melting point	446 ° C
boiling point	1171 ° C
solubility	very good in water (1650 g l −1 at 20 ° C); good in DMSO (410 g l −1 at 25 ° C); very good in ethanol ;
Refractive index	1,955
safety instructions
GHS labeling of hazardous substances Caution
H and P phrases	H: 315-319
	P: 305 + 351 + 338
Thermodynamic properties
ΔH f 0	−270.08 kJ mol −1
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . Refractive index: Na-D line , 20 ° C

Lithium iodide , LiI is the lithium salt of hydriodic acid . In addition to the anhydrous lithium iodide, there are also various hydrates , known are LiI · nH ₂ O with n = 0.5, 1, 2 and 3.

Extraction and presentation

Lithium iodide is produced by reacting aqueous lithium hydroxide or lithium carbonate solutions with hydrogen iodide , followed by concentration and drying.

{\ displaystyle {\ ce {LiOH + HI -> LiI + H2O}}}

{\ displaystyle {\ ce {Li2CO3 + 2HI -> 2LiI + H2O + CO2 ^}}}

The anhydrous lithium iodide can also be prepared by reacting lithium hydride with iodine in anhydrous diethyl ether .

{\ displaystyle {\ ce {LiH + I2 -> LiI + HI}}}

properties

Lithium iodide forms colorless, highly hygroscopic crystals with a melting point of 446 ° C, a boiling point of 1180 ° C and a density of 3.49 g cm ⁻³ . The molar mass of the anhydrous lithium iodide is 133.85 g / mol. The oxidation of iodide to iodine by air oxygen causes the crystals to quickly turn yellowish to brownish in color.

The trihydrate has a melting point of 73 ° C. When heated, it loses two molecules at 80 ° C and another molecule of crystal water at 300 ° C. Lithium iodide is readily soluble in water (1650 g / l water at 20 ° C) and ethanol.

The standard enthalpy of formation of crystalline lithium iodide is Δ _f H ⁰₂₉₈ = −270.08 kJ / mol.

use

The anhydrous lithium iodide is used for organic syntheses, in lithium iodine batteries it serves as an electrolyte . Doped crystals serve as a scintillation detector for slow neutrons .

Individual evidence

↑ ^a ^b ^c ^d ^e ^f ^g ^h Entry on lithium iodide in the GESTIS substance database of the IFA , accessed on January 8, 2020(JavaScript required) .
↑ Dimethyl Sulfoxide (DMSO) Solubility Data. Gaylord Chemical Company, LLC; Bulletin 102, June 2014, p. 14. (PDF)
^ G. Milne: Gardner's Commercially Important Chemicals: Definitions, Trade Names, and Properties. P. 370, Wiley-IEEE, 2005, ISBN 9780471736615 .
↑ David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Index of Refraction of Inorganic Crystals, pp. 10-246.
↑ Entry on lithium iodide (Condensed phase thermochemistry data). In: P. J. Linstrom, W. G. Mallard (Eds.): NIST Chemistry WebBook, NIST Standard Reference Database Number 69 . National Institute of Standards and Technology , Gaithersburg MD, accessed November 17, 2019.
^ ^A ^b ^c ^d A. F. Holleman , E. Wiberg , N. Wiberg : Textbook of Inorganic Chemistry . 101st edition. Walter de Gruyter, Berlin 1995, ISBN 3-11-012641-9 , pp. 1151-1152.
↑ MD Taylor, LR Grant: New Preparations of Anhydrous Iodides of Groups I and II Metals , in: J. Am. Chem. Soc. 1955 , 77 , 1507-1508
^ GF Hüttig, F. Pohle: Studies on the chemistry of lithium. II. About the hydrates of lithium iodide , in: Z. anorg. allg. Chem. 1924 , 138 , 1-12.
↑ Oliver Herzberg: Investigation of organic solid-state reactions using the example of substitution and polycondensation reactions , dissertation, University of Hamburg 2000. DNB 960245774/34

↑ LF Trueb, P. Rüetschi: Batteries and accumulators - Mobile energy sources for today and tomorrow. , Springer, Berlin 1998 ISBN 3-540-62997-1 .

↑ KP Nicholson: Some lithium iodide phosphors for slow neutron detection , in: J. Appl. Phys. 1955 , 6 , 104-106.

[GESTIS-1] ↑ ^a ^b ^c ^d ^e ^f ^g ^h Entry on lithium iodide in the GESTIS substance database of the IFA , accessed on January 8, 2020(JavaScript required) .

[2] Dimethyl Sulfoxide (DMSO) Solubility Data. Gaylord Chemical Company, LLC; Bulletin 102, June 2014, p. 14. (PDF)

[3] G. Milne: Gardner's Commercially Important Chemicals: Definitions, Trade Names, and Properties. P. 370, Wiley-IEEE, 2005, ISBN 9780471736615 .

[CRC90_10_246-4] David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Index of Refraction of Inorganic Crystals, pp. 10-246.

[nist.gov-5] Entry on lithium iodide (Condensed phase thermochemistry data). In: P. J. Linstrom, W. G. Mallard (Eds.): NIST Chemistry WebBook, NIST Standard Reference Database Number 69 . National Institute of Standards and Technology , Gaithersburg MD, accessed November 17, 2019.

[wiberg-6] A ^b ^c ^d A. F. Holleman , E. Wiberg , N. Wiberg : Textbook of Inorganic Chemistry . 101st edition. Walter de Gruyter, Berlin 1995, ISBN 3-11-012641-9 , pp. 1151-1152.

[7] MD Taylor, LR Grant: New Preparations of Anhydrous Iodides of Groups I and II Metals , in: J. Am. Chem. Soc. 1955 , 77 , 1507-1508

[8] GF Hüttig, F. Pohle: Studies on the chemistry of lithium. II. About the hydrates of lithium iodide , in: Z. anorg. allg. Chem. 1924 , 138 , 1-12.

[Herzberg-9] Oliver Herzberg: Investigation of organic solid-state reactions using the example of substitution and polycondensation reactions , dissertation, University of Hamburg 2000. DNB 960245774/34

[10] LF Trueb, P. Rüetschi: Batteries and accumulators - Mobile energy sources for today and tomorrow. , Springer, Berlin 1998 ISBN 3-540-62997-1 .

[11] KP Nicholson: Some lithium iodide phosphors for slow neutron detection , in: J. Appl. Phys. 1955 , 6 , 104-106.