The “ nitrides ” of most nonmetals exist. By calling the compounds nitrides, it is indicated that the other
element has an electronegativity that is lower than that of nitrogen. Therefore, NO 2 , NF 3 , N 2 F 2 , and
the like would not be considered “ nitrides ” because the other element is the more electronegative. This
leaves quite a number of compounds such as HN 3 , S 4 N 4 , (CN) 2 , that are covalent nitrides. Chemically,
these compounds are quite different, and as will be shown later, methods for synthesizing them vary
enormously.