Engineering Molecular Organization of Naphthalenediimides: Large Nanosheets with Metallic Conductivity and Attoliter Containers

Abstract Molecular‐interaction‐induced organizations are the basis of various biological and nonbiological systems. The molecular recognition process involved in the formation of such systems is rather complicated, as it constitutes a subtle balance of various noncovalent interactions. The molecular organization of electron‐deficient aromatic systems is particularly appealing, as they are the potential candidates for a variety of applications. The main challenge in organizing aromatic moieties lies in controlling and optimizing the relatively strong π–π interactions by appropriate functionalization. Herein, we describe a simple molecular design involving phenylalanine methylester‐functionalized naphthalenediimide (L‐NDI and D‐NDI) to achieve high‐level molecular ordering by solution processing. NDIs are among the most promising organic n‐type semiconductors. However the molecular ordering of these organic entities determines their optimal functioning in an organic device. Highly crystalline free‐floating nanosheets with large lateral dimensions were obtained for the first time through molecularly engineered self‐assembly of L‐NDI and D‐NDI systems. Interestingly the nanosheets exhibit a remarkable conductivity of 1.6 S cm⁻¹. Furthermore the molecular organization of L‐NDI was tuned into container‐like complex architectures by employing chlorinated‐ co‐solvent‐mediated halogen bonding. The composition and the type of chlorinated co‐solvent resulted in the formation of nanocups, mesocups, and bowl‐like architectures. The nanocups possess a net volume of 0.1–1.5 attoliters (10⁻¹⁸ L) and can be used as containers for miniaturized applications.