Ion-Pairing Assemblies of π-Electronic Anions Formed by Intramolecular Hydrogen Bonding.

π-Extended nitro-substituted dipyrrolylphenol derivatives were synthesized, and upon deprotonation they provided π-electronic anions stabilized by hydrogen bonding between the phenolate (phenoxide) moiety and the pyrrole NH group. Ion-pairing assemblies of the deprotonated anions were formed in the solid state and as mesophases. In the solid state, the extended π plane was found to be more suitable to form charge-by-charge assemblies in combination with tetraalkylammonium cations with highly anisotropic orientations as a result of efficient stacking. The mesophase also included a charge-by-charge assembly comprising the deprotonated anion bearing aliphatic chains, as revealed by synchrotron X-ray diffraction analysis.