isocyanurates

Isocyanurates are a class of coordination compounds that contain a central nitrogen atom bound to three identical groups, typically carbonyl or alkyl groups. In chemistry these complexes are often called tricarbocyanurates when the ligands are cyanate groups. The most common example is sodium or calcium isocyanurate, also known as sodium cyclohexane-1,3,5-trisulfate, which is widely used as a source of chlorine or bromine for water treatment and disinfection.

The compounds were first isolated in the late 19th century when chemists investigated the properties of cyanate salts. Because the nitrogen atom can form three rings of equal length, the resulting structures are relatively stable and can be stored for extended periods without significant decomposition. In aqueous solution the isocyanurate salts dissociate into their constituent ions, releasing active chlorine or bromine that oxidizes organic matter and kills microorganisms. This makes them a popular alternative to sodium hypochlorite in swimming pools, municipal water supplies and industrial processes.

Isocyanurate compounds are manufactured by reacting cyanuric acid with an alkali hydroxide, typically sodium hydroxide or calcium hydroxide, under controlled temperature conditions. The reaction generates the trimeric isocyanurate ring and releases water. Because the reaction is exothermic, precise temperature control is required to avoid runaway reactions or excessive humidity.

Safety considerations for handling isocyanurates include avoiding inhalation of dust and preventing contact with skin and eyes, as the compounds can cause irritation. Proper ventilation and personal protective equipment, such as gloves and goggles, reduce exposure risks. In summary, isocyanurates are stable, chlorine-releasing salts that play a significant role in water purification and disinfection processes.