Thiocyanic acid
From Wikipedia, the free encyclopedia
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Names | |||
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IUPAC name
Nitridosulfanidocarbon[2]
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Other names
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Identifiers | |||
463-56-9 ![]() |
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3DMet | B00344 | ||
ChEBI | CHEBI:29200 ![]() |
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ChEMBL | ChEMBL84336 ![]() |
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ChemSpider | 760 ![]() |
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ECHA InfoCard | 100.006.672 | ||
EC Number | 207-337-4 | ||
25178 | |||
Jmol 3D model | Interactive image | ||
KEGG | C01755 ![]() |
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MeSH | thiocyanic+acid | ||
PubChem | 781 | ||
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Properties | |||
CHNS | |||
Molar mass | 59.09 g·mol−1 | ||
Appearance | colorless, oily liquid | ||
Odor | pungent | ||
Density | 2.04 g/cm3 | ||
Melting point | 5 °C (41 °F; 278 K) | ||
Miscible | |||
Solubility | soluble in ethanol, diethyl ether | ||
log P | 0.429 | ||
Acidity (pKa) | 0.926 | ||
Basicity (pKb) | 13.071 | ||
Hazards | |||
EU classification (DSD)
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R-phrases | R20/21/22, R32, R52/53 | ||
S-phrases | (S2), S13 | ||
Related compounds | |||
Related alkanenitriles
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Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references | |||
Thiocyanic acid is a chemical compound with the formula HSCN which exists as a tautomer with isothiocyanic acid (HNCS).[3] The iso- form tends to dominate with the material being about 95% isothiocyanic acid in the vapor phase.[4]
It is a weak acid, bordering on strong, with a pKa of 1.1 at 20 °C and extrapolated to zero ionic strength.[5]
HSCN is predicted to have a triple bond between carbon and nitrogen. It has been observed spectroscopically but has not been isolated as a pure substance.[6]
The salts and esters of thiocyanic acid are known as thiocyanates. The salts are composed of the thiocyanate ion (−SCN) and a suitable metal cation (e.g., potassium thiocyanate, KSCN). The esters of thiocyanic acid have the general structure R–SCN.
References[edit]
- ^ Merck Index, 11th Edition, 9257.
- ^ "thiocyanic acid (CHEBI:29200)". Chemical Entities of Biological Interest. USA: European Bioinformatics Institute. 18 October 2009. Main. Retrieved 5 June 2012.
- ^ Holleman, A. F.; Wiberg, E. (2001). Inorganic Chemistry. San Diego: Academic Press. ISBN 0-12-352651-5.
- ^ Beard, C. I.; Dailey, B. P. (1950). "The Structure and Dipole Moment of Isothiocyanic Acid". The Journal of Chemical Physics. 18 (11): 1437. doi:10.1063/1.1747507.
- ^ Martell, A. E.; Smith, R. M.; Motelaitis, R. J. (2001). NIST Database 46. Gaithersburg, MD: National Institute of Standards and Technology.
- ^ Wierzejewska, M.; Mielke, Z. (2001). "Photolysis of Isothiocyanic Acid HNCS in Low-Temperature Matrices. Infrared Detection of HSCN and HSNC Isomers". Chemical Physics Letters. 349: 227–234. doi:10.1016/S0009-2614(01)01180-0.