On the basis of the chemistry in solution, the solid‐state structures and the corresponding electronic and optical properties of dipyrrolyldiketone boron complexes as π‐conjugated acyclic anion receptors have been investigated. Solid‐state assemblies of the receptors exhibit anion‐dependent properties that are in sharp contrast to those in the solution state. Anion complexation, along with structural differences in the pyrrole subunits such as a benzo‐fused pyrrole, plays an essential role not only in the formation of the assembled modes but also in determining electronic and optical properties, as well as the charge‐carrier mobilities. In addition, by anion complexation, inclusion of the counter cations into the crystals has also been found to be one of the essential factors to determine the properties.