Rhodanwasserstoffsäure

HSCN · Thiocyanic acid · Sulfocyanic acid · hydrogen thiocyanate

Identifikatoren & physikalische Daten

CAS No.	463-56-9
Summenformel	HSCN
Durchschnittliche Molmasse	59,09 g/mol
Monoisotopische Masse	58,98297003 g/mol
SMILES	N#CS
InChIKey	ZMZDMBWJUHKJPS-UHFFFAOYSA-N
PubChem CID	781
ChEMBL	CHEMBL84336
ChEBI	CHEBI:29200
EC No.	207-337-4
DTXSID	DTXSID7047221
Lokaler Name	Rhodanwasserstoffsäure

Chemische & physikalische Eigenschaften

XLogP	0,6
Polarare Oberfläche (TPSA)	24,8
H-Brücken-Donoren	1
H-Brücken-Akzeptoren	2
Frei drehbare Bindungen	0
Schwere Atome	3
Formalladung	0
Komplexität	31,3
Stoffklassen	Other Classes -> Organic AcidsIonic Liquids
SpringerMaterials Properties	Moessbauer quadrupole effect
LogP (Verteilungskoeffizient)	0.58 (estimated)
Löslichkeit	Solubility in water: good
Schmelzpunkt	5 °C-110 °C
Dampfdichte	Relative vapor density (air = 1): 2.0
Dampfdruck	4.73 [mmHg]
Physical Description	Colorless gas or white solid (depends on degree of polymerization)[Merck Index] Colorless liquidmp = 5 deg C[ICSC]COLOURLESS LIQUID.
Collision Cross Section	99.8 Å² [M-H]- [CCS Type: DTBuffer gas: N2Ionization: ESI-Dataset: TOXCASTSource Identifier: DTXSID4021343]
Siedepunkt	-87.78°C (estimate)
Dichte	1.228 (estimate)
Brechungsindex	1.4640 (estimate)
pKa (Säurekonstante)	0.93±0.10(Predicted)
pH	pKa1= –0.87(25℃)
LogP (Verteilungskoeffizient)	0.429 (est)
EPA chemische Informationen	Thiocyanic acid (463-56-9)

Sicherheit & Vorschriften

GHS-Einstufung	WarningH302: Harmful if swallowed [Warning Acute toxicity, oral]P261, P264, P270, P271, P273, P280, P301+P317, P302+P352, P304+P340, P317, P321, P330, P362+P364, and P501 (click each P-code to see the statement)
Brandgefahren	Not combustible. Gives off irritating or toxic fumes (or gases) in a fire.
Gefahrenübersicht	A very strong acid[Merck Index] Polymerizes on warmingChronic exposure may cause hypothyroidism[ICSC] See Sodium thiocyanate.
EG-Einstufung	Symbol: XnR: 20/21/22-32-52/53S: (2)-13-61
Chemical Dangers	The substance polymerizes due to warming. Decomposes on heating. This produces toxic fumes. Reacts violently with strong bases and strong oxidants. This produces toxic fumes including hydrogen cyanide.
Physical Dangers	The vapour is heavier than air.
Packaging and Labelling	Do not transport with food and feedstuffs.
Hazard Classes and Categories	Acute toxicity - category 4Acute Tox. 4 *
Brandbekämpfung	In case of fire in the surroundings, use appropriate extinguishing media.
Erste-Hilfe-Maßnahmen	Fresh air, rest.Remove contaminated clothes. Rinse and then wash skin with water and soap.First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention.Rinse mouth. Give one or two glasses of water to drink. Refer for medical attention .
Sichere Lagerung	Separated from strong oxidants, strong bases and food and feedstuffs. Ventilation along the floor.
Verschüttetes entsorgen	Personal protection: filter respirator for acid gases and vapours adapted to the airborne concentration of the substance. Collect leaking and spilled liquid in covered containers as far as possible. Carefully collect remainder. Then store and dispose of according to local regulations.
Eye Prevention	Wear safety spectacles.
Fire Prevention	NO contact with acids, bases or oxidizing agents.
Inhalation Risk	No indication can be given about the rate at which a harmful concentration of this substance in the air is reached on evaporation at 20 °C.
Skin Prevention	Protective gloves.
Ingestion Prevention	Do not eat, drink, or smoke during work.
Inhalation Prevention	Use ventilation, local exhaust or breathing protection.
Effects of Long Term Exposure	The substance may have effects on the thyroid. This may result in hypothyroidism.
Treatment	In cases of thiocyanate exposure, get fresh air and medical attention. If not breathing, give artificial respiration. If breathing is difficult, give oxygen. If swallowed, do not induce vomiting but give large quantities of water. Immediately flush skin with plenty of water for at least 15 minutes in case of exposure to skin or the eyes. (L217)Antidotes to cyanide poisoning include hydroxocobalamin and sodium nitrite, which release the cyanide from the cytochrome system, and rhodanase, which is an enzyme occurring naturally in mammals that combines serum cyanide with thiosulfate, producing comparatively harmless thiocyanate. Oxygen therapy can also be administered. (L97)
Gesundheitliche Auswirkungen	Thiocyanates are known to affect the thyroid glands, reducing the ability of the gland to produce hormones that are necessary for the normal function of the body. Exposure to high levels of cyanide for a short time harms the brain and heart and can even cause coma and death. (L191)Exposure to high levels of cyanide for a short time harms the brain and heart and can even cause coma, seizures, apnea, cardiac arrest and death. Chronic inhalation of cyanide causes breathing difficulties, chest pain, vomiting, blood changes, headaches, and enlargement of the thyroid gland. Skin contact with cyanide salts can irritate and produce sores. (L96, L97)
Unerwünschte Wirkungen	Neurotoxin - Other CNS neurotoxin
Expositionspfade	The substance can be absorbed into the body by inhalation of its vapour and by ingestion.Oral (L191)inhalation (L191)dermal (L191)Inhalation (L96)oral (L96)dermal (L96)
Toxizitätsübersicht	Thiocyanate (sulphocyanate or SCN) is believed to be a goitrogenic compound. It is a competitive inhibitor of the human thyroid sodium/iodide symporter NIS. Thus, the adverse effects of thiocyanate overload are especially noticeable when iodine availability is low. Intake of goitrogenic substances causes an adaptive increase in T3‰ЫЄs binding to brain nuclear receptors and in the activity of type II 5'-deiodinase, which generates T3 from T4. This altered function and availability of T3 is detrimental to the developing brain. Thiocyanate is also known to modulate activity of mammalian peroxidases. For instance, eosinophil peroxidase has been implicated in promoting oxidative tissue damage in a variety of inflammatory conditions, including asthma. Thiocyanate also acts as inhibitor to carbonic anhydrase, which catalyzes the rapid conversion of carbon dioxide to bicarbonate and protons. (A139, A143, A149) Organic nitriles decompose into cyanide ions both in vivo and in vitro. Consequently the primary mechanism of toxicity for organic nitriles is their production of toxic cyanide ions or hydrogen cyanide. Cyanide is an inhibitor of cytochrome c oxidase in the fourth complex of the electron transport chain (found in the membrane of the mitochondria of eukaryotic cells). It complexes with the ferric iron atom in this enzyme. The binding of cyanide to this cytochrome prevents transport of electrons from cytochrome c oxidase to oxygen. As a result, the electron transport chain is disrupted and the cell can no longer aerobically produce ATP for energy. Tissues that mainly depend on aerobic respiration, such as the central nervous system and the heart, are particularly affected. Cyanide is also known produce some of its toxic effects by binding to catalase, glutathione peroxidase, methemoglobin, hydroxocobalamin, phosphatase, tyrosinase, ascorbic acid oxidase, xanthine oxidase, succinic dehydrogenase, and Cu/Zn superoxide dismutase. Cyanide binds to the ferric ion of methemoglobin to form inactive cyanmethemoglobin. (L97)Organic nitriles decompose into cyanide ions both in vivo and in vitro. Consequently the primary mechanism of toxicity for organic nitriles is their production of toxic cyanide ions or hydrogen cyanide. Cyanide is an inhibitor of cytochrome c oxidase in the fourth complex of the electron transport chain (found in the membrane of the mitochondria of eukaryotic cells). It complexes with the ferric iron atom in this enzyme. The binding of cyanide to this cytochrome prevents transport of electrons from cytochrome c oxidase to oxygen. As a result, the electron transport chain is disrupted and the cell can no longer aerobically produce ATP for energy. Tissues that mainly depend on aerobic respiration, such as the central nervous system and the heart, are particularly affected. Cyanide is also known produce some of its toxic effects by binding to catalase, glutathione peroxidase, methemoglobin, hydroxocobalamin, phosphatase, tyrosinase, ascorbic acid oxidase, xanthine oxidase, succinic dehydrogenase, and Cu/Zn superoxide dismutase. Cyanide binds to the ferric ion of methemoglobin to form inactive cyanmethemoglobin. (L97)
Signs and Symptoms	Symptoms of thiocyanate exposure include rapid, deep breathing and shortness of breath, followed by convulsions (seizures) and loss of consciousness. (L191)Cyanide poisoning is identified by rapid, deep breathing and shortness of breath, general weakness, giddiness, headaches, vertigo, confusion, convulsions/seizures and eventually loss of consciousness. (L96, L97)
Carcinogen Classification	No indication of carcinogenicity to humans (not listed by IARC).
Toxicity Data	Guanidine Thiocyanate: LD50: 375 mg/kg (Oral, Rat), LD50: 2000 mg/kg (Dermal, Rabbit) (L218) Potassium Thiocyanate: LD50: 854 mg/kg (Oral, Rat) (L219) Ammonium Thiocyanate: LD50: 750 mg/kg (Oral, Rat), LD50: 500 mg/kg (Oral, Mouse) (L220)LD50: 500 mg/kg (Oral, Mouse) (L558) LD50: 500 mg/kg (Intraperitoneal, Mouse) (L558)
RAIS Toxicity Values	0.0002SCREEN Current0.0006PPRTV Current
EPA Provisional Peer-Reviewed Toxicity Values	Thiocyanic AcidPDF Document2012
Hazard Quotient Level 0.1 or Cancer Risk Level 1E-06	1.60e+012.30e+024.00e+002.00e+002.00e-04Volatile
Hazard Quotient Level 3 or Cancer Risk Level 1E-04	4.70e+017.00e+021.20e+012.00e+002.00e-04Volatile
TSCA-Inventar-Status	TSCA listed
R-Sätze (R)	20/21/22-32-52/53
Gefahrensymbole	Xn
Sicherheitshinweise (S)	13-61

Anwendungen & Verwendung

Verwenden

Thiocyanic acid can be used to prepare thiocyanates, esters, various thiocyanates, and cyanides. SCN ions are excellent ligands. A particularly sensitive reaction of SCN ions is the formation of various red complexes with Fe. Therefore, potassium thiocyanate or ammonium thiocyanate are commonly used as reagents for testing for Fe.