302-04-5

Basic information

• Product Name: thiocyanic acid
• Synonyms: Thiocyanate;THIOCYANATEION;Thiocyanic acid anion;[S-C#N](-);Chebi:18022;Nitridosulfidocarbonate(1-);Nitridothiocarbonate(1-);Nitridothiocarbonate(iv)
• CAS NO: 302-04-5
• Molecular Formula: CNS
• Molecular Weight: 58.08
• Mol File: 302-04-5.mol
• Article Data: 26

Chemical Properties

• Melting Point: 168-169 °C
• Boiling Point: 146°Cat760mmHg
• Flash Point: 42.1°C
• Appearance: /
• Density: 1.126g/cm³
• Vapor Pressure: 4.73mmHg at 25°C
• Storage Temp.: -20°C
• CAS DataBase Reference: thiocyanic acid(CAS DataBase Reference)
• NIST Chemistry Reference: thiocyanic acid(302-04-5)
• EPA Substance Registry System: thiocyanic acid(302-04-5)

Safety Data

• Hazardous Substances Data: 302-04-5(Hazardous Substances Data)

Usage

Uses

Different sources of media describe the Uses of 302-04-5 differently. You can refer to the following data:
1. Fumigants.
2. Thiocyanate is one of the most important spectrophotometric reagents. The availability of the reagent and the simplicity of thiocyanate methods are responsible for its great popularity in analytical laboratories. Thiocyanate is principally used for determination of Fe(III), Mo, W, Nb, Re, Co, U, and Ti. The determination of metals by thiocyanate is carried out in aqueous or aqueous-acetone media, or after extraction with oxygen-containing solvents. The extractability of metal complexes depends on the acidity of the medium, the concentration of thiocyanate, and the organic solvent. The more acidic is the aqueous phase, and the higher the thiocyanate concentration, the more thiocyanic acid (HSCN) is also extracted by the organic phase. Stepwise formation of thiocyanate complexes gives cationic (e.g., FeSCN2+), neutral [e.g., Fe(SCN)3], and anionic [e.g., Fe(SCN)4-] species. The last is formed at high thiocyanate concentrations. With organic bases such as pyridine, tributylamine, and diantipyrylmethane, anionic thiocyanate complexes form ion-pairs which can be extracted into chloroform and other inert solvents. Increased selectivity in the determination of metals by thiocyanate is obtained by the choice of acidity, thiocyanate concentration, masking agent, and metal oxidation state. For example, the presence of a reducing agent is necessary for colour reactions with Mo, W, and Re. The reducing medium precludes the colour reaction of thiocyanate with iron. Thiocyanate methods vary widely in sensitivity. The methods for determining Te, Fe(III), and Nb are highly sensitive, whereas those for U and Co are less sensitive. The colour stability of some thiocyanate systems is low (e.g., that with iron). This is connected with either the reducing properties of the thiocyanate or the slow polymerization of thiocyanic acid in acid solutions, which causes yellowing. Solvents miscible with water increase the colour intensity of thiocyanate complexes in aqueous solutions. This is apparently owing to the lowered dielectric constants of the media, which inhibit dissociation of the complexes. Anionic thiocyanate complexes are extractable as ion-association species with basic dyes.

Definition

Different sources of media describe the Definition of 302-04-5 differently. You can refer to the following data:
1. thiocyanate: A salt or ester of thiocyanicacid.
2. ChEBI: A pseudohalide anion obtained by deprotonation of the thiol group of thiocyanic acid.

Hazard

Rapid-acting poisons, thyrotoxic.

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

Upstream product

• 556-61-6 methyl thioisocyanate 
• 13453-08-2 trithiocarbonic acid; ammonium salt (1:2) 
• 10097-32-2 bromide 
• 1701-93-5 silver thiocyanate 
• 16887-00-6 chloride 
• 463-58-1 carbon oxide sulfide 
• 506-77-4 cyanogen chloride 
• 74-93-1 methylthiol 
• 26041-18-9 sulfide ion 
• 52666-91-8 thiocyanic acid ; copper (II)-compound with ammonia 
• 64253-39-0 hypothiocyanous acid 
• 7732-18-5 water 
• 505-14-6 thiocyanogen 
• 57-12-5 cyanide^(1-) 

Downstream Products

• 3034-29-5 2-methyl-1-phenyl-2-thiocyanatopropan-1-one 
• 58808-44-9 4-bis(2-hydroxyethyl)aminophenylacetic acid 
• 556-64-9 methyl thiocyanate 
• 506-68-3 bromocyane 
• 10097-32-2 bromide 
• 14808-79-8 Sulfate 
• 71000-82-3 cyanate 
• 14265-45-3 sulfite^(2-) 

Relevant articles and documents

Photoredox chemistry in the synthesis of 2-aminoazoles implicated in prebiotic nucleic acid synthesis

Prebiotically plausible ferrocyanide-ferricyanide photoredox cycling oxidatively converts thiourea to cyanamide, whilst HCN is reductively homologated to intermediates which either react directly with the cyanamide giving 2-aminoazoles, or have the potential to do so upon loss of HCN from the system. Thiourea itself is produced by heating ammonium thiocyanate, a product of the reaction of HCN and hydrogen sulfide under UV irradiation. This journal is

Thiophosphate - A Versatile Prebiotic Reagent?

Described are our preliminary studies on the reactivity of thiophosphate in a setting which correlates with the cyanosulfidic systems chemistry we have previously reported. Thiophosphate adds to various nitrile groups giving the corresponding thioamides in a highly efficient manner and the mechanistic implications are briefly discussed. Thiophosphate can also act as a phosphorylating agent, which was demonstrated with adenosine. The prebiotic availability of thiophosphate must be questioned, but if a plausible synthesis can be found, the advantages it would bring to the field of prebiotic chemistry appear to be highly beneficial.

Mechanism of decomposition of the human defense factor hypothiocyanite near physiological pH

Relatively little is known about the reaction chemistry of the human defense factor hypothiocyanite (OSCN-) and its conjugate acid hypothiocyanous acid (HOSCN), in part because of their instability in aqueous solutions. Herein we report that HOSCN/OSCN- can engage in a cascade of pH- and concentration-dependent comproportionation, disproportionation, and hydrolysis reactions that control its stability in water. On the basis of reaction kinetic, spectroscopic, and chromatographic methods, a detailed mechanism is proposed for the decomposition of HOSCN/OSCN- in the range of pH 4-7 to eventually give simple inorganic anions including CN -, OCN-, SCN-, SO32-, and SO42-. Thiocyanogen ((SCN)2) is proposed to be a key intermediate in the hydrolysis; and the facile reaction of (SCN) 2 with OSCN- to give NCS(=O)SCN, a previously unknown reactive sulfur species, has been independently investigated. The mechanism of the aqueous decomposition of (SCN)2 around pH 4 is also reported. The resulting mechanistic models for the decomposition of HOSCN and (SCN) 2 address previous empirical observations, including the facts that the presence of SCN- and/or (SCN)2 decreases the stability of HOSCN/OSCN-, that radioisotopic labeling provided evidence that under physiological conditions decomposing OSCN- is not in equilibrium with (SCN)2 and SCN-, and that the hydrolysis of (SCN)2 near neutral pH does not produce OSCN-. Accordingly, we demonstrate that, during the human peroxidase-catalyzed oxidation of SCN-, (SCN)2 cannot be the precursor of the OSCN- that is produced.