isocyaan

Isocyaan is a class of organic compounds characterized by the presence of the isocyanate functional group, which has the structure R-N=C=O. This group is known for its high reactivity, particularly with nucleophiles such as alcohols, amines, and water. The general formula for isocyanates is R-N=C=O, where R is an organic substituent. They are isomeric with cyanates, which have the structure R-O-C≡N.

The synthesis of isocyanates can be achieved through various methods, a common one being the phosgenation of primary amines. In this reaction, a primary amine reacts with phosgene (COCl₂) to form an isocyanate and hydrogen chloride. Another method involves the thermal decomposition of carbamates.

Due to their reactivity, isocyanates are important intermediates in the synthesis of a wide range of polymers, most notably polyurethanes. Polyurethanes are formed by the reaction between diisocyanates and diols. The versatility of isocyanates allows for the production of diverse materials with varied properties, including flexible and rigid foams, elastomers, coatings, and adhesives. However, many isocyanates are toxic and require careful handling due to their irritating and sensitizing properties.