Self‐assembled Helical Tetramer Stack of Terrylene Bisimide in Solution and Crystalline State

A terrylene bisimide (TBI) derivative $\bf1$ bearing bulky meta-terphenyl imide substituents is shown to self-assemble into helical $\bf{[1_4]}$ tetramer stacks in solution. Driven by strong dispersion and electrostatic forces, a direct transition from monomers into defined tetramers is already observed in the micromolar concentration range (∼10$^{−6}$ M) in methylcyclohexane at room temperature, corresponding to a π–π-interaction strength of ΔG = −40.1 kJ mol$^{−1}$ for the respective π–π-stacking interaction between two neighboring TBIs. Upon addition of perylene ($\bf{P}$), a further growth of the stacks toward $\bf{[P.1_4.P]}$ hexalayers is observed where the guest molecules are stacked at the peripheral positions. In contrast, upon addition of the larger coronene ($\bf{C}$), the equilibrium shifts toward 1:2 complexes $\bf{[C.1.C]}$ where each TBI is surrounded by two coronene neighbors. Single crystal X-ray analyses of the pristine $\bf{[1_4]}$ tetramer stack as well as the $\bf{[P.1_4.P]}$ hexalayer stack and the 1:2 trilayer $\bf{[C.1.C]}$ unambiguously confirm the unique stacking arrangements.