Azanes with more than three nitrogen atoms can be arranged in various different ways, forming structural isomers. The simplest isomer of an azane is the one in which the nitrogen atoms are arranged in a single chain with no branches. This isomer is sometimes called the n-isomer (n for "normal", although it is not necessarily the most common). However the chain of nitrogen atoms may also be branched at one or more points. The number of possible isomers increases rapidly with the number of nitrogen atoms.
Due to the low energy of inversion, unsubstituted branched azanes cannot be chiral. In addition to these isomers, the chain of nitrogen atoms may form one or more loops. Such compounds are called cycloazanes.