Ammonium thiocyanate
[CAS# 1762-95-4]

Identification

• Classification: Inorganic chemical industry >> Inorganic salt >> Cyanide, cyanide oxide and cyanide complex
• Name: Ammonium thiocyanate
• Synonyms: Ammonium sulfocyanide; Ammonium rhodanide
• Molecular Formula: NH₄SCN
• Molecular Weight: 76.12
• CAS Registry Number: 1762-95-4 (92568-90-6)
• EC Number: 217-175-6
• SMILES: C(#N)[S-].[NH4+]

Properties

• Density: 1.305 g/mL (20 °C) (Expl.)
• Melting point: 152-154 °C (Expl.)
• Boiling point: 170 °C (760 mmHg) (Expl.)
• Water solubility: 163 g/100 mL (20 °C)

Safety Data

• Hazard Symbols: GHS06;GHS07 Danger
• Risk Statements: H302-H312-H318-H332-H412
• Safety Statements: P261-P264-P264+P265-P270-P271-P273-P280-P301+P317-P302+P352-P304+P340-P305+P354+P338-P317-P321-P330-P362+P364-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Acute toxicity	Acute Tox.	4	H302
Acute toxicity	Acute Tox.	4	H332
Acute toxicity	Acute Tox.	4	H312
Chronic hazardous to the aquatic environment	Aquatic Chronic	3	H412
Serious eye damage	Eye Dam.	1	H318
Chronic hazardous to the aquatic environment	Aquatic Chronic	1	H410
Acute hazardous to the aquatic environment	Aquatic Acute	1	H400
Specific target organ toxicity - repeated exposure	STOT RE	1	H372

Discovery and Applications

Ammonium thiocyanate, with the chemical formula NH4SCN, is an inorganic compound that consists of ammonium cations (NH4+) and thiocyanate anions (SCN−). It is a white, crystalline solid that is highly soluble in water and has a faint odor. The compound is used in a variety of applications across multiple industries, including analytical chemistry, agriculture, and chemical synthesis.

The discovery of ammonium thiocyanate dates back to the 19th century, and it was first synthesized by reacting ammonia (NH3) with carbon disulfide (CS2) to form ammonium xanthate, which then decomposes to produce ammonium thiocyanate. This method remains one of the primary ways to synthesize the compound today.

Ammonium thiocyanate has several important applications, particularly in analytical and chemical processes. One of its most notable uses is in the analysis of metal ions. It is commonly used in the preparation of reagents for qualitative inorganic analysis, where it reacts with certain metal ions to form precipitates or colored complexes. The compound is used for the detection of metals such as iron, cobalt, and copper, where the thiocyanate ion forms well-defined complexes with these ions.

In the agricultural industry, ammonium thiocyanate has been employed as a herbicide. It is sometimes used to control the growth of unwanted plants in certain environments, although its use as a pesticide has been limited due to environmental concerns and regulatory restrictions. The compound's potential to inhibit plant growth is primarily due to the thiocyanate anion, which can disrupt essential biochemical processes in plants.

Another significant use of ammonium thiocyanate is in the production of certain chemicals. It is involved in the synthesis of thiocyanate salts, which are valuable in a range of chemical applications. These derivatives are used in the manufacture of dyes, plastics, and as chemical intermediates in organic synthesis. Additionally, ammonium thiocyanate is used in the production of silver thiocyanate (AgSCN), a compound that has applications in photographic processes and in the manufacture of certain types of batteries.

Ammonium thiocyanate also plays a role in the preparation of certain polymer materials, particularly in the synthesis of polythiocyanates. These polymers have applications in coatings and in the production of materials with specific chemical properties, such as corrosion resistance.

In summary, ammonium thiocyanate is an important compound used across a variety of industries. It serves as a key reagent in analytical chemistry, plays a role in chemical synthesis, and has applications in agriculture and material production. Its ability to form stable complexes with metal ions and its reactivity make it a valuable substance in both industrial and scientific contexts.

References

1975. [Metabolism of 3-amino-1,2,4-triazole in rats]. Archives of toxicology, 34.
DOI: 10.1007/bf00353851

2016. Imidazolium-based ionic liquids for cellulose pretreatment: recent progresses and future perspectives. Applied Microbiology and Biotechnology, 101.
DOI: 10.1007/s00253-016-8057-8

2001. Chemical Carboxyl-Terminal Sequence Analysis of Peptides and Proteins Using Tribenzylsilyl Isothiocyanate. Journal of Protein Chemistry, 20.
DOI: 10.1023/a:1013367728843