Hydrogen Bonding in Nitroanilines: Neutron Diffraction Study of <i>m</i>-Nitroaniline at 100 K

An appreciable degree of pyramidalization of the amine nitrogen atom is observed in the
title compound. The existence of polar chains, induced by N−H···O synthons and stabilized
by a C(ar)−H···O interaction, is confirmed. An N−H···N interaction, disregarded in molecular
orbital calculations, was found to stabilize even further the known head-to-head assembling
of the chains and to be responsible for the polar layer's formation. The structure can be
described as polar layers on the bc plane, embodying chains interlinked by N−H···N
interactions and connected by weak C(aryl)−H···O interactions.