Supramolecular Polymerization of C3-Symmetric, Triphenylene-Cored Aza-Polycyclic Aromatic Hydrocarbons with Excellent and Switchable Circularly Polarized Luminescence Performance

Abstract

A new type of C3-symmetric aza-polycyclic aromatic hydrocarbon (PAH) discs attached with chiral alkoxyl chains is developed and explored as circularly polarized luminescence (CPL)-active materials with selective control and switching of chiroptical properties. Supramolecular polymerization of these PAHs is studied experimentally and theoretically. With the aid of weak hydrogen bonding and CH···π interactions, these chromophores have strong tendency to form anisotropic chiral aggregates both in solutions and films. The well-controlled noncovalent interactions are critical for their excellent CPL performance. The resultant supramolecular polymers display a polarized emission band with the maximum glum value up to 10–2. Benefited from the chiral supramolecular polymerization process and N-doping structure feature of the core, on/off CPL switching from these molecules can be reversibly realized by external stimuli including the change of temperature, solvent, and pH conditions. Our work shows that chiral supramolecular polymers from concise yet highly rigid and planar PAH cores are superbly suitable for exceptional CPL emission both in dilute solutions and bulk materials, with a promising switchable CPL feature, thereby unlocking new design possibilities.