Isocyanate

In organic chemistry, isocyanate is a functional group (a piece of a molecule) with the chemical formula : a nitrogen atom connected to the larger molecule, with a double bond to a carbon atom, which has its own double bond to an oxygen atom.

Isocyanates are used to make polyurethanes, a type of plastic, and some pesticides. Notable isocyanates include methylene diphenyl diisocyanate (MDI), toluene diisocyanate (TDI), and methyl isocyanate (MIC).

 Production 
In the chemical industry, isocyanates are made from phosgene and a primary amine (a chemical with a  group), with hydrogen chloride as a byproduct. A simple example is the reaction of phosgene with methylamine to make methyl isocyanate:

This reaction is conducted in anhydrous conditions, meaning no water is present, because water can cause a runaway reaction with isocyanates. The water-isocyanate reaction is what caused the Bhopal disaster, the worst industrial accident in history.

Phosgene is a dangerous gas that needs special equipment to use safely. Oxalyl chloride is an alternative to phosgene used in research. Researchers are interested in other ways to make isocyanates without using chlorine compounds.

 References 

Category:Functional groups
Category:Isocyanates