Molecular Design Leveraging Non-Covalent Interactions for Efficient Light-Emitting Organic Small Molecules

Light-emitting organic small molecules require high internal and external quantum efficiencies with excellent radiative characteristics for their potential application in next-generation optoelectronics. Nonetheless, achieving high efficiency in solid states remains a formidable challenge, primarily owing to the non-radiative processes. Therefore, conformational modulation in solid states is pivotal in influencing emission properties to mitigate non-radiative decay. Notably, modifying intra- and intermolecular non-covalent interactions (NCIs) is a promising strategy that can simultaneously realize rigidity and stabilization of flexible single bonds, thus suppressing reorganization energy associated with non-radiative decay. Consequently, considerable emission enhancement is attainable through adept manipulation of NCIs, corresponding to systems ranging from single molecules to multimolecular networks in solid states. This review systematically summarizes and analyzes the influence of diverse NCIs in efficient light-emitting organic small molecules. The effects of NCIs on single-and multimolecular-systems are discussed, based on the fundamentals of light emission mechanism and the correlation between molecular design strategy and photophysical properties. Additionally, strategic perspectives are provided for the advancement of future light-emitting organic small molecules. Therefore, this review serves as a comprehensive molecular design library, providing an up-to-date overview of molecular design leveraging NCIs for efficient light-emitting organic small molecules.