A variety of anion-responsive π-electronic systems (anion receptors) based on a 1,3-dipyrrolylpropane-1,3-dione framework have been synthesized. The anion receptors form complexes with anions, affording diverse modes including [1+1]-type planar complexes. Anion complexes of the π-electronic systems form ion pairs with cationic species, resulting in assembled structures. Through interionic interactions and other noncovalent interactions, ion-pairing assemblies construct ordered structures in bulk materials such as crystals, supramolecular gels, and thermotropic liquid crystals, exhibiting fascinating electronic properties including semiconductive behaviors.