Assembly of diverse molecular aggregates with a single, substrate-directed molecule orientation.

Oriented, fluorescing organic nanoaggregates derived from 1,4'''-dicyano-functionalized para-quaterphenylene (CNP4) are obtained upon vacuum deposition on muscovite mica. Two types of aggregates are observed with fiber- and wing-like shape, respectively, both growing along distinct substrate directions. The polarization of the emitted fluorescence, their morphology, and their electric surface potential differ, reflecting different polymorphs. The wings are chiral twins. The molecules orient within ±5° along the same direction, templated by the substrate.