71000-82-3

Basic information

• Product Name: cyanic acid
• Synonyms: Cyanate;C01417
• CAS NO: 71000-82-3
• Molecular Formula: CHNO
• Molecular Weight: 42.02
• Mol File: 71000-82-3.mol
• Article Data: 34

Chemical Properties

• Boiling Point: 23.5°C at 760 mmHg
• Appearance: /
• Vapor Pressure: 813mmHg at 25°C
• CAS DataBase Reference: cyanic acid(CAS DataBase Reference)
• NIST Chemistry Reference: cyanic acid(71000-82-3)
• EPA Substance Registry System: cyanic acid(71000-82-3)

Safety Data

• Hazardous Substances Data: 71000-82-3(Hazardous Substances Data)

Usage

General Description

A class of generally colorless liquids with slight odors. Toxic by inhalation. Irritate skin, eyes, and mucous membranes. Decompose to emit toxic nitric oxide and cyanide fumes when heated to high temperatures. May be combustible. Used to make other chemicals.

Air & Water Reactions

Most react with water to generate highly toxic fumes.

Reactivity Profile

Isocyanates and thioisocyanates are incompatible with many classes of compounds, reacting exothermically to release toxic gases. Reactions with amines, aldehydes, alcohols, alkali metals, ketones, mercaptans, strong oxidizers, hydrides, phenols, and peroxides can cause vigorous releases of heat. Acids and bases initiate polymerization reactions in these materials. Some isocyanates react with water to form amines and liberate carbon dioxide. Base-catalysed reactions of isocyanates with alcohols should be carried out in inert solvents. Such reactions in the absence of solvents often occur with explosive violence [Wischmeyer1969].

Health Hazard

TOXIC; inhalation, ingestion or contact (skin, eyes) with vapors, dusts or substance may cause severe injury, burns or death. Bromoacetates and chloroacetates are extremely irritating/lachrymators. Reaction with water or moist air will release toxic, corrosive or flammable gases. Reaction with water may generate much heat that will increase the concentration of fumes in the air. Fire will produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause pollution.

Fire Hazard

HIGHLY FLAMMABLE: Will be easily ignited by heat, sparks or flames. Vapors form explosive mixtures with air: indoors, outdoors and sewers explosion hazards. Most vapors are heavier than air. They will spread along ground and collect in low or confined areas (sewers, basements, tanks). Vapors may travel to source of ignition and flash back. Substance will react with water (some violently) releasing flammable, toxic or corrosive gases and runoff. Contact with metals may evolve flammable hydrogen gas. Containers may explode when heated or if contaminated with water.

InChI:InChI=1/CHNO/c2-1-3/h3H/p-1

Synthetic route

cyanide(1-) (57-12-5) → cyanate (71000-82-3)

Conditions	Yield
With 4,40-Di-tert-butyl-2,20-bipyridine; dihydrogen peroxide In N,N-dimethyl-formamide at 20℃; for 2.5h; Catalytic behavior; Kinetics; Reagent/catalyst;	100%
With alkali peroxide In not given in alkaline soln.;;
With chlorine In water byproducts: Cl(1-); introduction of Cl2 into alkali cyanide soln.;

isocyanomethide anion (81704-80-5) → cyanide(1-) (57-12-5) + cyanate (71000-82-3)

Conditions	Yield
With oxygen at 24.9℃; under 0.4 Torr; Product distribution; various neutral molecules with or without acidic hydrogen;

methyl isocyanate (624-83-9) → methyl hydroperoxide (3031-73-0) + cyanide(1-) (57-12-5) + cyanate (71000-82-3) + C2H3NO2(1-) + HO

Conditions	Yield
With hydroperoxide anion In gaseous matrix at 26.9℃; Rate constant; Product distribution; in a flowing afterglow system (flow rector affixed to a quadrupole mass spectrometer);

Thiocyanate (302-04-5) → cyanate (71000-82-3)

Conditions	Yield
With {Ni(OH)2(H3IO6)2}(2-) Kinetics; byproducts: SO4(2-), H2O; oxidation in aq. alkaline medium, pH=8-10;

Thiocyanate (302-04-5) + chlorite (14998-27-7) + water (7732-18-5) → cyanate (71000-82-3) + chloride (16887-00-6) + Sulfate (14808-79-8) + hydrogen cation

Conditions	Yield
In perchloric acid Kinetics; 25°C, ionic strength 0.5 M (NaClO4); not isolated; UV/VIS monitoring (360 nm);

hydroxide + Thiocyanate (302-04-5) → cyanate (71000-82-3)

Conditions	Yield
With chloramine-B or bromamine-B In water Kinetics; byproducts: SO4(2-); oxidation of thiocyanate ion by chloramine-B or bromamine-B in alkaline medium (293-323 K) for 24 h;

potassium cyanide + ozone (10028-15-6) → cyanate (71000-82-3) + oxygen (80937-33-3)

Conditions	Yield
In water pH=11-12;
In water pH=11-12;

thallium (III) oxide + hydrogen cyanide (74-90-8) + water (7732-18-5) → thallium(I) ion + cyanate (71000-82-3) + Ammonium

Conditions	Yield
In water byproducts: (CONH2)2; reduction of Tl(III) oxide with HCN in H2O; NMR;

urea (57-13-6) → cyanate (71000-82-3) + Ammonium

Conditions	Yield
In water Kinetics; izomerization;
thermal decompn.; identified by IR;

cyanogen iodide (506-78-5) → cyanate (71000-82-3) + iodide (14362-44-8)

Conditions	Yield
With sodium hydroxide In water Kinetics; basic hydrolysis of cyanogen iodide at room temp.; monitored by UV-spectroscopy of the I(1-) species;

sodium cyanide (773837-37-9) → cyanate (71000-82-3)

Conditions	Yield
In water Electrolysis; electrolysis with Pt electrode at anodic potenitals at 0.15 V in pH 12 soln.; mechanism discussed;; detn. by IR;;

sodium cyanide (773837-37-9) + copper(ll) sulfate pentahydrate + dihydrogen peroxide (7722-84-1) + sodium hydroxide (1310-73-2) → cyanate (71000-82-3) + copper hydroxide (20427-59-2)

Conditions	Yield
In water Kinetics; addn. of H2O2 to soln. of other educts (pH = 10);

potassium hexacyanoferrate(III) → cyanate (71000-82-3) + carbonate(2-) (3812-32-6)

Conditions	Yield
With air In solid heated to 490 ° C in static air atm at heating rate 5 °/min (TG/DSC expt.);; detected by IR;;

potassium hexacyanoferrate(III) → cyanate (71000-82-3) + carbonate(2-) (3812-32-6) + hexacyanoferrate(II)

Conditions	Yield
With air In solid heated to 350 ° C in static air atm at heating rate 5 °/min (TG/DSC expt.);; detected by IR;;

potassium hexacyanoferrate(III) → cyanate (71000-82-3) + hexacyanoferrate(II)

Conditions	Yield
With air In solid heated to 300 ° C in static air atm at heating rate 5 °/min (TG/DSC expt.);; detected by IR;;

carbon monoxide (201230-82-2) + ammonia (7664-41-7) → cyanate (71000-82-3)

Conditions	Yield
With catalyst Pd/Al2O3 In neat (no solvent) byproducts: H(1+); exposing a Pd/Al2O3 catalyst to 15 Torr of a CO/NH3 mixt. (2:1) at 298 K for 30 min; detd. by IR spectroscopy;
formation of surface isocyanate on iron surface (silica-supported iron catalyst) from coadsopted CO/NH3 mixt. at 298-523 K; IR;

potassium cyanide + potassium hypochlorite → cyanate (71000-82-3)

Conditions	Yield
equiv. amts. of educts;
equiv. amts. of educts;

carbon dioxide (124-38-9) + amide → isocyanic acid (75-13-8) + cyanate (71000-82-3)

Conditions	Yield
In neat (no solvent, gas phase) byproducts: H2O, OH(1-); in flowing afterglow system at 298 K, at 0,3-0.4 torr and 140-190 cm3/s He.;

potassium cyanide + sodium hypochlorite (7681-52-9) → cyanate (71000-82-3)

Conditions	Yield
byproducts: formate, carbonate;
byproducts: formate, carbonate;

methyl isocyanate (624-83-9) + hydroperoxide anion (14691-59-9) → cyanide(1-) (57-12-5) + hydroxyl (3352-57-6) + cyanate (71000-82-3)

Conditions	Yield
In gas Kinetics; byproducts: CH3NCO2(1-), (CH4O3), CH3O2H; gas-phase react. of hydroperoxide with CH3NCO; not isolated; detn. by mass spectroscopy;;

ammonium chloride + pyrographite (7440-44-0) → cyanate (71000-82-3)

Conditions	Yield
in high-frequency spark; identified by MS;

tetracyanonickelate(II) (48042-08-6) + hypobromite → nickel(III) oxide hydrate + cyanate (71000-82-3)

Conditions	Yield
In water at pH = 8.5 - >10;;

cyanide(1-) (57-12-5) + hypobromite → cyanate (71000-82-3)

Conditions	Yield
In water in alkaline soln.;
In water in alkaline soln.;

iron(III) oxide + Thiocyanate (302-04-5) → cyanate (71000-82-3)

Thiocyanate (302-04-5) + calcium oxide → cyanate (71000-82-3)

Thiocyanate (302-04-5) + zinc(II) oxide → cyanate (71000-82-3)

smithsonite (743369-26-8) + Thiocyanate (302-04-5) → cyanate (71000-82-3)

siderite (767234-62-8) + Thiocyanate (302-04-5) → cyanate (71000-82-3)

tetrahydroxyargentate(III) + Thiocyanate (302-04-5) → cyanate (71000-82-3) + silver thiocyanate (1701-93-5)

Conditions	Yield
In water Kinetics; byproducts: SO4(2-), H2O, OH(1-); UV, IR;

trans-dicarbonyl(nitratomercurio)(η5-cyclopentadienyl)(dimethylphenylarsine)molybdenum + cyanate (71000-82-3) → trans-dicarbonyl(cyanatomercurio)(η5-cyclopentadienyl)(dimethylphenylarsine)molybdenum

Conditions	Yield
In tetrahydrofuran to complex in THF was added anion; water was added, product was extracted into CH2Cl2, crystd. upon the addition Et2O;	90%

trans-dicarbonyl(nitratomercurio)(η5-cyclopentadienyl)(triphenylphosphine)molybdenum + cyanate (71000-82-3) → trans-dicarbonyl(η5-cyclopentadienyl)(cyanatomercurio)(triphenylphosphine)molybdenum

Conditions	Yield
In tetrahydrofuran to complex in THF was added anion; water was added, product was extracted into CH2Cl2, crystd. upon the addition Et2O;	90%

sodium azide + copper(II) nitrate trihydrate + cyanate (71000-82-3) + N,N-dimethylethylenediamine (108-00-9) → [Cu(N3)(NCO)(N,N-dimethylethylenediamine)]2 (477935-95-8)

Conditions	Yield
In methanol; water aq. soln. of NaN3, NCO(1-) added to soln. of Cu(NO3)2*3H2O and org. ligand in MeOH; mixt. stirred for 30 min at 299 K; filtered; washed (Et2O); dried (vac.); elem. anal.;	70%

NbCl2(C6H4O2)(OC6H4OH) (105659-10-7) + cyanate (71000-82-3) → (CNO)2Nb(OC6H4O)(OC6H4OH) (110625-38-2)

Conditions	Yield
In tetrahydrofuran NaNCO or KNCO was added to a THF soln. of Nb-compound in 2:1 ratio under anhyd. conditions, mixt. was stirred and refluxed for ca. 12 h at 65-70°C; filtered, ppt. was washed with THF, filtrate and washings were evapd. in vacuo (2 h), residue was recrystd. from EtOH, dried under vac. (0.4 mmHg); elem. anal.;	48%

Nb(5+)*2Cl(1-)*C6H3O2(OH)(2-)*2H(1+)*C6H3O3(3-)=NbCl2(C6H3O2(OH))(OC6H3(OH)2) + cyanate (71000-82-3) → Nb(5+)*2NCO(1-)*C6H3O2(OH)(2-)*2H(1+)*C6H3O3(3-)=Nb(NCO)2(C6H3O2(OH))(OC6H3(OH)2)

Conditions	Yield
In tetrahydrofuran NaOCN or KOCN was added to a THF soln. of Nb-compound in 2:1 ratio under anhyd. conditions, mixt. was stirred and refluxed for ca. 12 h at 65-70°C; filtered, ppt. was washed with THF, filtrate and washings were evapd. in vacuo (2 h), residue was recrystd. from EtOH, dried under vac. (0.4 mmHg); elem. anal.;	45%

pyridine (110-86-1) + cyanate (71000-82-3) + manganese (II) acetate tetrahydrate (6156-78-1) + trimethyleneglycol (504-63-2) → [Mn(III)11Mn(II)6(OCN)7(O2CMe)2(1,3-propanediolato)10(pyridine)4]

Conditions	Yield
In pyridine; acetonitrile Mn acetate, propanediol and OCN(1-) reacted in MeCN-pyridine;	32%

L-ornithine (70-26-8) + cyanate (71000-82-3) → Nα-carbamoyl-(S)-citrulline (117920-63-5)

Upstream product

• 81704-80-5 isocyanomethide anion 
• 624-83-9 methyl isocyanate 
• 302-04-5 Thiocyanate 
• 14998-27-7 chlorite 
• 7732-18-5 water 
• 10028-15-6 ozone 
• 74-90-8 hydrogen cyanide 
• 57-13-6 urea 
• 506-78-5 cyanogen iodide 
• 773837-37-9 sodium cyanide 
• 7722-84-1 dihydrogen peroxide 
• 1310-73-2 sodium hydroxide 
• 201230-82-2 carbon monoxide 
• 7664-41-7 ammonia 

Downstream Products

• 57-13-6 urea 
• 7727-37-9 nitrogen 
• 598-55-0 methyl carbamate 
• 75-13-8 isocyanic acid 
• 57-12-5 cyanide^(1-) 
• 127-07-1 N-hydroxyurea 
• 110625-38-2 (CNO)2Nb(OC₆H₄O)(OC₆H₄OH) 

Relevant articles and documents

Synthesis, application and AIE properties of novel fluorescent tetraoxocalix[2]arene[2]triazine: The detection of a hazardous anion, cyanate

A highly effective, new heterocalixarene fluorescent receptor comprised of 2-(2-aminophenyl)benzothiazole and tetraoxacalix[2]arene[2]triazine was designed and synthesized by one-step reaction. The sensor candidate exhibiting aggregation induced emission (AIE) was tested for its photophysical behaviour towards detection of various anions. The results showed that our receptor undergo AIE in >40% H2O-DMSO along with large pseudo Stokes shift (Δλ = 219 nm) and exhibit selective and sensitive detection towards hazardous cyanide's oxidation product, cyanate (CNO-) ion over other tested anions. The blue-shifted fluorescence emission (λem = 492 nm) enhancement with large Stokes shift (Δλ = 144 nm) was observed with the increase in cyanate concentration. The synthesized turn-on sensor towards cyanate detection could be applied in real sample analyses as an improvement to the method currently carried out by international standards and hereby a different approach has been made for the detection of cyanide through its oxidation form, cyanate.

A Multifunctional Bimetallic Molecular Device for Ultrasensitive Detection, Naked-Eye Recognition, and Elimination of Cyanide Ions

A new bimetallic FeII-CuII complex was synthesized, characterized, and applied as a selective and sensitive sensor for cyanide detection in water. This complex is the first multifunctional device that can simultaneously detect cyanide ions in real water samples, amplify the colorimetric signal upon detection for naked-eye recognition at the parts-per-million (ppb) level, and convert the toxic cyanide ion into the much safer cyanate ion in situ. The mechanism of the bimetallic complex for high-selectivity recognition and signaling toward cyanide ions was investigated through a series of binding kinetics of the complex with different analytes, including CN-, SO42-, HCO3-, HPO42-, N3-, CH3COO-, NCS-, NO3-, and Cl- ions. In addition, the use of the indicator/catalyst displacement assay (ICDA) is demonstrated in the present system in which one metal center acts as a receptor and inhibitor and is bridged to another metal center that is responsible for signal transduction and catalysis, thus showing a versatile approach to the design of new multifunctional devices.

Oxidation of thiocyanate with H2O2 catalyzed by [RuIII(edta)(H2O)]-

The [RuIII(edta)(H2O)]- (edta4- = ethylenediaminetetraacetate) complex is shown to catalyze the oxidation of thiocyanate (SCN-) with H2O2 mimicking the action of peroxidases. The kinetics of the catalytic oxidation process was studied by using stopped-flow and rapid scan spectrophotometry as a function of [RuIII(edta)], [H2O2], [SCN-], pH (3.2-9.1) and temperature (15-30 °C). Spectral analyses and kinetic data are suggestive of a catalytic pathway in which hydrogen peroxide reacts directly with thiocyanate coordinated to the RuIII(edta) complex. Catalytic intermediates such as [RuIII(edta)(OOH)]2- and [Ru V(edta)(O)]- were found to be non-reactive in the oxidation process under the specified conditions. Formation of SO 42- and OCN- was identified as oxidation products in ESI-MS experiments. A detailed mechanism in agreement with the spectral and kinetic data is presented. The Royal Society of Chemistry 2013.