In chemistry, a nitride is a compound of nitrogen where nitrogen has a formal oxidation state of −3. Nitrides are a large class of compounds with a wide range of properties and applications.The nitride ion, N 3− , is never encountered in solution because it is so basic that it would be protonated.Its ionic radius is estimated to be 140 pm.Related to but distinct from nitride is pernitride, N 2 2− .itrides are a large class of compounds with a wide range of properties and applications. The nitride ion, N 3− , is never encountered in solution because it is so basic that it would be protonated. Its ionic radius is estimated to be 140 pm. Related to but distinct from nitride is pernitride, N 2 2− .