143-33-9 Usage
Uses
Used in Mining Industry:
Sodium cyanide is used as an extraction agent for extracting gold and silver from ores. Gold (or silver) reacts with sodium cyanide in the presence of air to form the complex sodium cyanurate, which dissolves the gold from the ore. Further reaction with zinc can displace gold, generating sodium cyanate and freeing the gold out.
Used in Electroplating Industry:
Sodium cyanide is used as an electroplating agent for metals such as zinc, copper, cadmium, silver, and gold, and their alloys.
Used in Chemical Synthesis:
Sodium cyanide is used as a starting material for the preparation of Reissert compounds, cyanogen bromide, cyanuric chloride, and cyanogen chloride. It acts as a catalyst for the aminolysis of esters to primary amides.
Used in Metallurgy:
Sodium cyanide is used for case hardening steel by liquid nitriding and as a modifying reagent for selective flotation of ores containing galena, sphalerite, and gangue minerals.
Used in Organic Synthesis:
Sodium cyanide is involved in the cyanation reaction of alkyl halides under phase transfer conditions.
Used in Agriculture:
Sodium cyanide is used as a fumigant and a chelating agent.
Used in Manufacturing:
Sodium cyanide is used in the production of hydrocyanic acid and other cyanides, as well as in the synthesis of DL-methionine.
Used in Steel Industry:
Sodium cyanide can act as a liquid steel carburizing agent with barium chloride, usually accompanied by a bath temperature of 800°C or more. It is important to add salts that do not cause NaCN evaporation at high temperatures.
Other Uses:
Sodium cyanide is also used for the production of iron blue (intermediate sodium ferrocyanide production), cyanuric chloride (intermediate product of cyanide production), and in pesticides and other purposes.
Toxicity
Sodium cyanide binds to the ferric iron of oxidized cytochrome oxidase, disabling its ability to deliver oxygen, resulting in tissue hypoxia, "intracellular asphyxia." Rat: oral administration-LD50: 6.44mg / kg, adult lethal dose 200mg. Being highly toxic.
It can be absorbed through the respiratory tract, digestive tract and skin. Animals, after inhaling sodium cyanide aerosol of 40mg-90mg / m3, get symptoms of irritations, irritability and salivation after 25 to 43 minutes. Inhalation of 150mg ~ 170mg / m3 for 62 to 76 minutes or inhalation of 400mg ~ 500mg / m3 for 20 minutes can cause death. Human oral LD50 is about 1mg ~ 2mg / kg. Under normal conditions of production, sodium cyanide dust is often inhaled at room temperature, and sodium vapor can be inhaled during heat treatment. Misdiagnosis is also one of the common causes of poisoning. In the event of a fire, try to prevent the generation of toxic hydrogen cyanide gas. Do not use carbon dioxide or acid-base foam fire extinguishers. Fire-fighting operation personnel must wear protective equipment, try not to contact with water containing sodium cyanide. This product is toxic with poisoning causing dizziness and other uncomfortable symptoms. When found, patients should immediately leave the contaminated area to the fresh air and taken 1% soda solution as first aid, at the same time, go to the hospital for treatment. UN No.: 1689/6257 / 6.1-04 / 215.
Preparation
1.(Castner improved method) sodium metal and ammonia as raw material to generate sodium amide, and then subjects to carbon reduction at 700 ~ 800 ℃to obtain the product [1].
2Na + 2NH3 → 2NaNH2 + H2
NaNH2 + C → [1] + H2
2. Natural gas (methane), ammonia, air as raw materials; their mixture is passed through the catalyst bed at 1000 ℃to generate hydrogen cyanide, followed by reaction with sodium hydroxide to obtain it [1].
HCN + NaOH → [1] + H2O
3. Hydrogen cyanide can obtained as byproduct during ammonia oxidation of propylene to generate acrylonitrile [1].
Preparation
Sodium cyanide can be prepared by several methods (See Potassium Cyanide).It is prepared by passing hydrogen cyanide through a 50% aqueous solution of sodium hydroxide followed by evaporation of the solution in vacuum: NaOH + HCN → NaCN + H2OAnother method is to reduce sodamide with carbon at red heat: NaNH2 + C → NaCN + H2↑Also, sodium cyanide can be made by heating a mixture of sodium carbonate and carbon with ammonia at high temperatures: Na2CO3 + 4C + 2NH3 → 2NaCN + 3CO↑ + 3H2↑.
Production Methods
Sodium cyanide was first prepared in 1834 by heating
Prussian Blue, a mixture of cyanogen compounds of iron,
and sodium carbonate and extracting sodium cyanide from
the cooled mixture using alcohol. Sodium cyanide remained
a laboratory curiosity until 1887, when a process was patented
for the extraction of gold and silver ores by means of a dilute solution of cyanide.
Reactions
Sodium cyanide, NaCN, white solid, soluble, very poisonous, formed (1) by reaction of sodamide and carbon at high temperature, (2) by reaction of calcium cyanamide and sodium chloride at high temperature, reacts in dilute solution in air with gold or silver to form soluble sodium gold or silver cyanide, and used for this purpose in the cyanide process for recovery of gold. The percentage of available cyanide is greater than in potassium cyanide previously used. Used as a source of cyanide, and for hydrocyanic acid.
Air & Water Reactions
Slowly evolves flammable and poisonous hydrogen cyanide gas.
Reactivity Profile
Sodium cyanide is weakly basic. Reacts with acids of all kinds to generate quantities of very poisonous hydrogen cyanide gas. Incompatible with strong oxidizing agents, especially if solution dries out. Gives insoluble products with silver(I), mercury(I) and lead(II) ions that may decompose violently under certain conditions.
Hazard
Toxic by ingestion and inhalation.
Health Hazard
Sodium cyanide is a highly poisonous compound by oral intake and by ocular and skin absorption. Accidental ingestion of a small quantity; as low as 100–150 mg could result in immediate collapse and instantaneous death in humans. At a lower dosage it can cause nausea, vomiting, hallucination, headache, and weakness. The toxicology of NaCN is the same as that of HCN. The metal cyanide forms HCN rapidly in the body, causing immediate death from a high dosage. The lethal effect from cyanide poisoning varied with species. Investigating the acute oral toxicity of sodium cyanide in birds, Wiemeyer et al. (1986) observed that the LD50 values for the flesh-eating birds were lower than that for the birds that fed on plant material; vulture 4.8 mg/kg versus chicken 21 mg/kg. In a study on marine species, Pavicic and Pihlar (1983) found that at 10 ppm concentration of NaCN, invertebrates were more sensitive than fishes. In animals, the lethal dose of NaCN were in the same range by different toxic routes. A dose of 8 mg NaCN/kg resulted in ataxia, immobilization, and death in coyotes (Sterner 1979); however, the lethal time was longer, at 18 minutes. Ballantyne (1983b) studied the acute lethal toxicity of sodium and other cyanides by ocular route. He found that cyanide instilled into the eye was absorbed across conjunctival blood vessels causing systemic toxicity and death within 3–12 minutes of the eye being contaminated. The toxicity of the cyanide did not decrease by mixing the solid with an inert powder such as kaolin. LD50 value, intraperitoneal (mice): 4.3 mg/kg LD50 value, oral (rats): 6.4 mg/kg Sodium cyanide is a teratogen, causing fetus damage and developmental abnormalities in the cardiovascular system in hamsters (NIOSH 1986). Sodium cyanide reacts with acids to form highly toxic hydrogen cyanide. There could be a slow liberation of HCN in contact with water.
Health Hazard
Sodium cyanide is a white crystalline solid that is odorless when dry, but emits a slight
odor of hydrogen cyanide in damp air. It is slightly soluble in ethanol and formamide. It is very poisonous. It explodes if melted with nitrite or chlorate at about 450°F. It produces
a violent reaction with magnesium, nitrites, nitrates, and nitric acid. On contact with acid,
acid fumes, water, or steam, it produces toxic and flammable vapors. Synonyms for sodium
cyanide are hydrocyanic acid, sodium salt, and cyanide of sodium.
Flammability and Explosibility
Sodium cyanide and potassium cyanide are noncombustible solids. Reaction with
acids liberates flammable HCN.
Safety Profile
A deadly human poison by ingestion. A deadly experimental poison by ingestion, intraperitoneal, subcutaneous, intravenous, parenteral, intramuscular, and ocular routes. An experimental teratogen. Human systemic effects by ingestion: hallucinations, dstorted perceptions, muscle weakness, and gastritis. Experimental reproductive effects.
hydrocyanic acid physiologically, inhibiting tissue oxidation and causing death through asphyxia. Cyanogen is probably as toxic as hydrocyanic acid; the nitriles are generally considered somewhat less toxic, probably because of their lower volathty. The nonvolaule cyanide salts appear to be relatively nonhazardous systemically, so long as they are not ingested and care is taken to prevent the formation of hydrocyanic acid. Workers, such as electroplaters and picklers, who are daily exposed to cyanide solutions may develop a “cyanide” rash, characterized by itching and by macular, papular, and vesicular eruptions. Frequently there is secondary infection. Exposure to small amounts of cyanide compounds over long periods of time is reported to cause loss of appetite, headache, weakness, nausea, dizziness, and symptoms of irritation of the upper respiratory tract and eyes.
moisture, acid. Many cyanides evolve hydrocyanic acid rather easily. This is a flammable gas and is highly toxic. Carbon dioxide from the air is sufficiently acidc to liberate hydrocyanic acid from cyanide solutions. Explodes if melted with nitrite or chlorate @ about 450”. Violent reaction with F2, Mg, nitrates, HNO3, nitrites. Upon contact with acid, acid fumes, water, or steam, it wdl produce toxic and flammable vapors of CNand NanO. Used in the extraction of gold and silver ores, in electroplating, and in insecticides. See also CYANIDE and HYDROCYANIC ACID,
The volaule cyanides resemble
Flammable by chemical reaction with heat,
Potential Exposure
Sodium cyanide is used as a solid or in solution to extract metal ores, in electroplating and metal cleaning baths; in metal hardening; in treatment of rabbit and rat burrows and holes and termite nests; in insecticides
storage
In
particular, work with cyanides should be conducted in a fume hood to prevent
exposure by inhalation, and splash goggles and impermeable gloves should be worn
at all times to prevent eye and skin contact. Cyanide salts should be stored in a cool,
dry location, separated from acids.
Shipping
UN1689 Sodium cyanide, Hazard Class: 6.1; Labels: 6.1-Poisonous materials.
Incompatibilities
Sodium cyanide decomposes on contact with acids, acid salts, water, moisture, alcohols, and carbon dioxide, releasing highly toxic and flammable hydrogen cyanide gas. Aqueous solution is a strong base; it reacts violently with acid and is corrosive. Incompatible with oxidizers (chlorates, nitrates, peroxides, permanganates, perchlorates, chlorine, bromine, fluorine, etc.); contact may cause fires or explosions. Keep away from alkaline materials, strong bases, strong acids, oxoacids, epoxides. Absorbs moisture from the air forming a corrosive syrup. Corrosive to active metals, such as aluminum, copper, and zinc. Under acid conditions, sarin hydrolyzes to form hydrofluoric acid.
Waste Disposal
Consult with environmental regulatory agencies for guidance on acceptable disposal practices. Generators of waste containing this contaminant (≥100 kg/mo) must conform to EPA regulations governing storage, transportation, treatment, and waste disposal. In accordance with 40CFR165, follow recommendations for the disposal of pesticides and pesticide containers. Must be disposed properly by following package label directions or by contacting your local or federal environmental control agency, or by contacting your regional EPA office. Add strong alkaline hypochlorite and react for 24 hours. Then flush to sewer with large volumes of water.
Check Digit Verification of cas no
The CAS Registry Mumber 143-33-9 includes 6 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 3 digits, 1,4 and 3 respectively; the second part has 2 digits, 3 and 3 respectively.
Calculate Digit Verification of CAS Registry Number 143-33:
(5*1)+(4*4)+(3*3)+(2*3)+(1*3)=39
39 % 10 = 9
So 143-33-9 is a valid CAS Registry Number.
InChI:InChI=1/CN.Na/c1-2;/rCNNa/c2-1-3
143-33-9Relevant articles and documents
STUDY OF PHASE TRANSFER CATALYSIS BY LAYERED SCINTILLATION METHOD.
Hideshima,Morinaga,Kimizuka
, p. 85 - 89 (1981)
The static and kinetic feature of the reaction of sodium cyanide with 1-bromoalkanes in the presence of various phase transfer catalysts was investigated in the oil/water system by using a layered scintillation method and the mechanism of catalytic action was discussed. From the measurement of equilibrium constants for both reactions of hexadecyltrimethylammonium cyanide with 1-bromooctane and of sodium cyanide with hexadecyltrimethylammonium bromide in organic phase, it was pointed out that the latter reaction was responsible for the advance of overall reaction. It is also found that majority of the phase transfer catalysts exist in the oil phase.
Physical Organic Studies on Bimolecular Reactions in Reversed Micelles: Addition of Cyanide Ion to the N-Methyl-3-carbamoylpyridinium Ion in Hexadecyltrimethylammonium Bromide Reversed Micelles
Goto, Ayako,Kishimoto, Hiroshi
, p. 73 - 78 (2007/10/02)
The bimolecular reaction of cyanide (CN-) ion with N-methyl-3-carbamoylpyridinium (S+) ion, in the water pool of the reversed-micellar system water/ hexadecyltrimethylammonium bromide (HTAB)/ chloroform-isooctane (3:2, v/v) has been studied at various temperatures (15-40 deg C) by measuring spectrophotometrically the decrease of the absorption due to S+ (265 nm) and the increase of the absorption due to the addition product (340 nm).The results of the reaction series were examined throughout with respect to the molar ratio of water to HTAB, R.Since the rate and equilibrium constants of the bimolecular reaction are affected by the method in which the concentrations of reactants are defined or by fixing the extent of reaction space, the water pool is assumed to be the sole reaction space and the rate and equilibrium constants in the water pool, k2w and Kw, which are based on the modified concentrations of the reaction species, have been evaluated.It is found that terms of k2w and Kw, the smaller the value of R, the more the addition reaction is enhanced.From the relationships between Kw and k2w vs. temperature, the standard and activation enthalpies of reaction, ΔH and ΔH, respectively, have been calculated.The behavior of ΔH and ΔH as well as Kw and k2w is found to differ in reactions which have R below and above ca.3.To explain the enhancement of the reaction due to the specific field effect of the water pool and the retardation of the reaction due to electrostatic interactions among S+ ions, the involvement of CN- and HTAB ions is proposed.The differing behaviour in the reactions is more clearly manifested in the thermodynamic and kinetic diagrams of enthalpy vs. entropy, which give separate plots corresponding to R both below and above ca.3.In addition, the effect of varying the CN- ion concentration is discussed and is found to be consistent with the situation described above.
STUDIES ON as-TRIAZINE DERIVATIVES. VII. RESEMBLANCE BETWEEN as-TRIAZINES AND QUINAZOLINES IN NUCLEOPHILIC ADDITION-ELIMINATION REACTIONS.
Konno, Shoetsu,Ohba, Setsuya,Sagi, Mataichi,Yamanaka, Hiroshi
, p. 1243 - 1246 (2007/10/02)
Alike 4-chloroquinazoline, 5-chloro-1,2,4-triazines (as-triazines) reacted with aromatic aldehydes in the presence of 1,3-dimethylbenzimidazolium iodide under basic conditions to give 5-aroyl-as-triazines.The Grignard reaction of 5-cyano-as-triazine with arylmagnesium bromides failed to give any significant product.Some analogy of as-triazines with quinazolines, in their chemical properties, was additionally investigated.
Monooxygen Donation Potential of 4a-Hydroperoxyflavins As Compared with Those of a Percarboxylic Acid and Other Hydroperoxides. Monooxygen Donation to Olefin, Tertiary Amine, Alkyl Sulfide, and Iodide Ion
Bruice, Thomas C.,Noar, J. Barry,Ball, Sheldon S.,Venkataram, U. V.
, p. 2452 - 2463 (2007/10/02)
The reaction of the hydroxyperoxides diphenylhydroperoxyacetonitrile (4), methyl diphenylhydroperoxyacetate (5), and 5',6',7',8'-tetrahydro-4a'-hydroperoxy-3'-methylspiro-4'(3'H)-one (6) with I-, thioxane, and N,N-dimethylbenzylamine (DMBA) are first order in both hydroperoxide and substrate.For both 5 and 6, I3- is produced in 100percent yield.Product analysis for the reaction of 4, 5, and 6 with thioxane and DMBA established that the hydroxyperoxides are converted to the corresponding alcohols and that thioxane sulfoxide and N,N-dimethylbenzylamine N-oxide are formed.The reactions are quantitative.The reaction of 4 with I- proved to be complicated.The alcohol generated from 4 is the cyanohydrin of benzophenone.The dissociation of the benzophenone cyanohydrin product is competitive with I3- formation so that CN- produced in the dissociation reacts with I3- to yield ICN.Kinetic and thermodynamic analyses have provided the pertinent rate and equilibrium constants associated with the overall time course for reaction of 4 with I-.The second-order rate constant for the reaction of m-chloroperbenzoic acid (1) with I- has been determined and the second-order rate constant for reaction of 1 with thioxane was obtained from experiments in which thioxane and I- were employed as competitive substrates.The second-order rate constants for reaction of 1, 4, 5, and 6 with I-, thioxane, and DMBA were compared with like constants for the reactions of 4a-hydroperoxy-5-ethyl-3-methyllumiflavin (2), 1-carba-1-deaza-4a-hydroperoxy-5-ethyl-3-methyllumiflavin (3), t-BuOOH (7), and H2O2 (8).A log - log plot of the rate constants for monooxygen transfer from hydroperoxides to thioxane (kS) and to DMBA (kN) was found to be linear and of slope 1.0.The best line for the plot of log kS vs. the log of the rate constants for reactions with I- (kI) was of slope 1.1.The points for m-chloroperbenzoic acid were found to fit the log kS vs. log KI plot.These results show that the second-order rate constants for reactions of I-, thioxane, and DMBA are of like dependence on the electronic and steric characteristics of the hydroperoxides and percarboxylic acid 1.A linear free energy plot correlates the log of the second-order rate constants vs. pKa of YOH for oxygen transfer from YOOH = 1, 2, 4, 5, 7, and 8 (βlg = -0.6).In these reactions the 4a-hydroperoxyflavin 2 is the most efficient monooxygen donor of the hydroperoxides investigated, being 103 - 106 more reactive than t-BuOOH and ca. 103 less reactive than the peracid 1.The kinetics of epoxidation of 2,3-dimethyl-2-butene by the hydroperoxides 2 - 6 were invesigated by following both hydroperoxide disappearance and product formation.The results of these investigations, which include further reaction of epoxide with hydroperoxide to provide pinacol and 2,3-dimethyl-1-buten-3-ol, are discussed.Evidence for epoxidation of 2,3-dimethyl-2-butene ...
CYCLIZATION OF HYDROXYIMINO-β-DICARBONYL COMPOUNDS WITH KETONES UNDER THE INFLUENCE OF ALKALI-METAL ALKOXIDES
Belyaev, E. Yu.,El'tsov, A. V.,Kochetkov, B. B.,Orlovskaya, N. F.,Tovbis, M. S.
, p. 1299 - 1304 (2007/10/02)
Investigation of the condensation of hydroxyimino-β-dicarbonyl compounds with acetone in the presence of sodium ethoxide by a spectrophotometric methods showed that the accumulation rate of 3,5-dimethyl-2-nitrosophenol in the reaction of hydroxyiminoacetylacetone with acetone increases with increase in the sodium ethoxide concentration.In the transition to arylated hydroxyimino-β-diketones p-nitrosophenols are formed exclusively and the reaction rate decreases, but increase in the electron-withdrawing characteristics of the substituent in the benzene ring of the hydroxyimino-β-dicarbonyl compound leads to an increase in the cyclization rate.For the case of the condensation of hydroxyiminoacetylacetone with acetone and methyl ethyl ketone an increase was found in the ratio of the para and ortho isomers of the nitrosophenols with decrease in the radius of the alkali metal, with substitution of potassium ethoxide by the alkoxides of tertiary alcohols, and with the use of solvents not containing hydroxyl group ( DMSO ).On the basis of the obtained data an improved preparative method was developed for the synthesis of p-nitrosophenols.A series of 2,3,5-trialkylnitrosophenols and previously unobtainable 3,5-di(aryl)heterylnitrosophenols were obtained.