CN compounds are compounds containing a cyanide or cyano group: a single carbon atom triple-bonded to a single, negatively charged nitrogen atom. Compounds that contain such a group are also known as cyanide compounds or cyanides.
Many organic molecules contain both carbon and nitrogen bonded and arranged in a myriad of ways, but cyanide compounds are special in that they are often highly toxic. They are called cyanides because they were discovered by heating Prussian blue, a pigment that is blue or cyan. The most toxic form of cyanide is the free cyanide group, consisting only of the carbon and nitrogen compound. Hydrogen cyanide, which is simply a cyanide group with a single hydrogen added, is also very toxic and is used in a variety of manufacturing processes.