Ammonium thiocyanate
| Chemical formula | NH4SCN |
| Density | 1.3 g/cm3 |
| Molar mass | 76.12 g/mol |
| CAS number | 1762-95-4 |
| EC index number | 615-004-00-3 |
| HS Code | 28323000 |
| EC number | 217-175-6 |
| Storage | Store at 5 to +30 °C |
| SDS | available |
| RTECS | XK7875000 |
| R phrase | R 20/21/22-32-52/53 |
| S phrase | S 13-61 |
| Odour | odourless |
| Form | solid |
| Color | colourless |
| p H value | 4.8 – 5.8(50 g/l 20 °C ) |
| Solubility in water | 1600g/l ( 20 °C ) |
| Solubility in ethanol | soluble |
| Melting point | ~150° C |
| Vapour pressure | <1 hPa |
| Thermal decomposition | >170° C |
| Assay | ≥ | 98/5 | % |
| Description | Conforms | ||
| Solubility | Conforms | ||
| Identification | Conforms | ||
| Appearance of solution | Conforms | ||
| Sulphide | ≤ | 0/002 | % |
| Heavy metals | ≤ | 0/002 | % |
| Sulfate | ≤ | 0/02 | % |
| Chloride | ≤ | 0/01 | % |
| Iron | ≤ | 0/0005 | % |
| Residue on ignition | ≤ | 0/05 | % |
Ammonium thiocyanate is a white, crystalline inorganic salt used as an analytical reagent, a source of thiocyanate in organic synthesis, and in some industrial processes such as metal plating, textile treatments, and the manufacture of certain pharmaceuticals and agrochemicals.
🏭⚗️ Production
Ammonium thiocyanate (NH₄SCN) is prepared industrially by neutralizing thiocyanic acid or thiocyanate-containing solutions with aqueous ammonia or by reaction of carbon disulfide derivatives followed by ammoniation; it is typically purified by recrystallization from water to give the white crystalline product.
🔬 Properties
The chemical formula is NH₄SCN with a molar mass of approximately 76.12 g/mol. It appears as a white, odorless, crystalline solid that is highly soluble in water and moderately soluble in alcohols; it is somewhat hygroscopic and decomposes on strong heating. The thiocyanate anion (SCN⁻) is a pseudohalide that forms colored complexes with many transition metal ions and participates readily in nucleophilic substitution and addition reactions in organic synthesis.
🧪 Applications
Ammonium thiocyanate is used in analytical chemistry (e.g., as a reagent for iron(III) producing a red complex), as a thiocyanate source in organic syntheses (to introduce SCN or convert to thiourea derivatives), in metal plating and surface treatments, and as an intermediate in the production of pharmaceuticals, agrochemicals, and certain dyes and rubber accelerators. It is also used in some laboratory procedures and research applications.
⚠️ Safety
Ammonium thiocyanate is of moderate toxicity; inhalation or ingestion can be harmful and repeated or high exposures may affect thyroid function because thiocyanate ions can interfere with iodine uptake. It can cause irritation to the eyes, skin, and respiratory tract; appropriate PPE (gloves, goggles, lab coat, and dust mask/respirator if dusty) should be used. Store in a cool, dry, well‑ventilated place away from strong oxidizers and acids; avoid ingestion, inhalation of dust, and release to the environment. Consult the material safety data sheet (MSDS/SDS) for detailed handling and emergency measures.
