Lithium perchlorate

Lithium perchlorate
Lithium perchlorate
The orthorhombic unit cell of lithium perchlorate under standard conditions.
__ Li+     __ Cl7+     __ O2−
Unit cell of lithium perchlorate.
Names
IUPAC name
Lithium perchlorate
Other names
Perchloric acid, lithium salt; Lithium Cloricum
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.029.307 Edit this at Wikidata
UNII
  • InChI=1S/ClHO4.Li/c2-1(3,4)5;/h(H,2,3,4,5);/q;+1/p-1 checkY
    Key: MHCFAGZWMAWTNR-UHFFFAOYSA-M checkY
  • InChI=1/ClHO4.Li/c2-1(3,4)5;/h(H,2,3,4,5);/q;+1/p-1
    Key: MHCFAGZWMAWTNR-REWHXWOFAR
  • [Li+].[O-]Cl(=O)(=O)=O
Properties
LiClO
4
Molar mass
  • 106.39 g/mol (anhydrous)
  • 160.44 g/mol (trihydrate)
Appearance White crystals
Odor Odorless
Density 2.42 g/cm3
Melting point 236 °C (457 °F; 509 K)
Boiling point 430 °C (806 °F; 703 K)
decomposes from 400 °C
  • 42.7 g/100 mL (0 °C)
  • 49 g/100 mL (10 °C)
  • 59.8 g/100 mL (25 °C)
  • 71.8 g/100 mL (40 °C)
  • 119.5 g/100 mL (80 °C)
  • 300 g/100 g (120 °C)[1]
Solubility Soluble in alcohols, ethyl acetate[1]
Solubility in acetone 137 g/100 g[1]
Solubility in alcohols
Solubility in ethyl acetate 95.2 g/100 g[2]
Solubility in ethyl ether 113.7 g/100 g[2]
Structure
Pnma, No. 62
a = 865.7(1) pm, b = 691.29(9) pm, c = 483.23(6) pm[3]
4 formula per cell
tetrahedral at Cl
Thermochemistry
105 J/mol·K[1]
125.5 J/mol·K[1]
−380.99 kJ/mol
−254 kJ/mol[1]
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
 Oxidizer, irritant
GHS labelling:
GHS03: OxidizingGHS07: Exclamation mark[4]
Danger
H272, H315, H319, H335[4]
P220, P261, P305+P351+P338[4]
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g. chloroformFlammability 0: Will not burn. E.g. waterInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazard OX: Oxidizer. E.g. potassium perchlorate
2
0
0
OX
Safety data sheet (SDS) MSDS
Related compounds
Other anions
 Lithium chloride
Lithium hypochlorite
Lithium chlorate
Other cations
 Sodium perchlorate
Potassium perchlorate
Rubidium perchlorate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Lithium perchlorate is the inorganic compound with the formula LiClO4. This white or colourless crystalline salt is noteworthy for its high solubility in many solvents. It exists both in anhydrous form and as a trihydrate.

Applications

Inorganic chemistry

Lithium perchlorate is used as a source of oxygen in some chemical oxygen generators. It decomposes at about 400 °C, yielding lithium chloride and oxygen:[5]

LiClO4 → LiCl + 2 O2

Over 60% of the mass of the lithium perchlorate is released as oxygen.[2] It has both the highest oxygen to weight and oxygen to volume ratio of all practical perchlorate salts, and higher oxygen to volume ratio than liquid oxygen.[6]

Lithium perchlorate is used as an oxidizer in some experimental solid rocket propellants, and to produce red colored flame in pyrotechnic compositions.[2][7]

Organic chemistry

LiClO4 is highly soluble in organic solvents, even diethyl ether. Such solutions are employed in Diels–Alder reactions, where it is proposed that the Lewis acidic Li+ binds to Lewis basic sites on the dienophile, thereby accelerating the reaction.[8]

Lithium perchlorate is also used as a co-catalyst in the coupling of α,β-unsaturated carbonyls with aldehydes, also known as the Baylis–Hillman reaction.[9]

Solid lithium perchlorate is found to be a mild and efficient Lewis acid for promoting cyanosilylation of carbonyl compounds under neutral conditions.[10]

Batteries

Lithium perchlorate is also used as an electrolyte salt in lithium-ion batteries. Lithium perchlorate is chosen over alternative salts such as lithium hexafluorophosphate or lithium tetrafluoroborate when its superior electrical impedance, conductivity, hygroscopicity, and anodic stability properties are of importance to the specific application.[11] However, these beneficial properties are often overshadowed by the electrolyte's strong oxidizing properties, making the electrolyte reactive toward its solvent at high temperatures and/or high current loads. Due to these hazards the battery is often considered unfit for industrial applications.[11]

Biochemistry

Concentrated solutions of lithium perchlorate (4.5 mol/L) are used as a chaotropic agent to denature proteins.

Production

Lithium perchlorate can be manufactured by reaction of sodium perchlorate with lithium chloride. It can be also prepared by electrolysis of lithium chlorate at 200 mA/cm2 at temperatures above 20 °C.[12]

Safety

Perchlorates often give explosive mixtures with organic compounds, finely divided metals, sulfur, and other reducing agents.[12][2]

References

  1. ^ a b c d e f g "Lithium perchlorate". chemister.ru.
  2. ^ a b c d e "Lithium Perchlorate". AMCP 706-187 Military Pyrotechnics - Properties of Materials. US Army Materiel Command. October 1963. pp. 181–182.
  3. ^ Wickleder, Mathias S. (2003). "Crystal Structure of LiClO4". Zeitschrift für Anorganische und Allgemeine Chemie. 629 (9): 1466–1468. doi:10.1002/zaac.200300114.
  4. ^ a b c Sigma-Aldrich Co., Lithium perchlorate. Retrieved on 2014-05-09.
  5. ^ Markowitz, M. M.; Boryta, D. A.; Stewart, Harvey Jr. (1964). "Lithium Perchlorate Oxygen Candle. Pyrochemical Source of Pure Oxygen". Industrial & Engineering Chemistry Product Research and Development. 3 (4): 321–330. doi:10.1021/i360012a016.
  6. ^ Herbert Ellern (1968). Military and Civilian Pyrotechnics. Chemical Publishing Company. p. 237. ISBN 978-0-8206-0364-3. OL 37082807M.
  7. ^ Basil T. Fedoroff; Oliver E. Sheffield (January 1975). "Lithium Perchlorate". Encyclopedia of explosives and related items. Vol. 7. Picatinny Arsenal. p. L45. LCCN 61-61759.
  8. ^ Charette, A. B. "Lithium Perchlorate" in Encyclopedia of Reagents for Organic Synthesis (Ed: L. Paquette) 2004, J. Wiley & Sons, New York. doi:10.1002/047084289X.
  9. ^ [1] Lithium Perchlorate Product Detail Page
  10. ^ N. Azizi, M.R. Saidi (2003). "An improved synthesis of cyanohydrins in the presence of solid LiClO4 under solvent-free conditions". Journal of Organometallic Chemistry. 688 (1–2): 283–285. doi:10.1016/j.jorganchem.2003.09.014.
  11. ^ a b Xu, Kang (2004). "Nonaqueous liquid electrolytes for lithium-based rechargeable batteries" (PDF). Chemical Reviews. 104 (10): 4303–4417. doi:10.1021/cr030203g. PMID 15669157. Retrieved 24 February 2014.
  12. ^ a b Helmut Vogt, Jan Balej, John E. Bennett, Peter Wintzer, Saeed Akbar Sheikh, Patrizio Gallone "Chlorine Oxides and Chlorine Oxygen Acids" in Ullmann's Encyclopedia of Industrial Chemistry 2002, Wiley-VCH. doi:10.1002/14356007.a06_483

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