Optoelectronic properties and applications of optically active binaphthol derivatives

Chiral binaphthol derivatives (BINOLs) have recently attracted considerable attention as active materials in photoelectric applications, such as sensors, organic light-emitting diodes (OLED) , nonlinear optics, and molecular machines, due to their particular C₂-unsymmetry, polysubstitution and stable chiral conformation. In this review, the design strategies and applications of BINOLs are summarized according to their different molecular modification methods. The relationships between structures and optoelectronic properties are also elucidated. Monosubstituted and polysubstituted BINOLs are mainly applied to fluorescent sensors based on photo-induced electron transfer (PET) and hydrogen bond interaction mechanisms. Disubstituted BINOLs are widely used in OLEDs, due to their outstanding optoelectronic properties that can be adjusted by changing the conformation and conjugation of the twisty π-conjugated naphthalene of BINOLs. There are also many other applications, such as in nonlinear optics and molecular machines grounding on the C₂-symmetric and chiral character of BINOLs. Further development and prospects of BINOLs are also discussed.