Tailoring Circularly Polarized Luminescence of Cholesteryl Conjugated Naphthalimides via Solvent Polarity

Rational manipulation of circularly polarized luminescence (CPL) properties is challenging in single component self-assembled systems. In this work we present a protocol to precisely tailor the CPL properties including handedness, dissymmetry factor (g(lum)), and wavelength of single component self-assemblies. A library of cholesteryl naphthalimides was built up with varied spacer and side arm groups. In aqueous media, building units self-assembled into vesicles with right-handed CPL, of which g(lum) values were at 10(-3) grade. Specifically, organogels were given in apolar solvent decane with excellent mechanical strength. The entangled gel networks possessed greatly enhanced g(lum) values at 10(-2) magnitude order, and CPL handedness was inverted to the left. In the presence of a small amount of water (1 vol %), crystalline precipitates were generated instead of original organogels, which further inverted CPL handedness to the right with diminished g(lum) values. The present solvent-polarity ultrasensitive property offers alternative thought to rationally enhance CPL with fine tailored handedness and wavelength in supramolecular systems.