Tunable Near‐White Light Emission From a Single‐Molecule via Strategic Utilization of Aldehyde‐Gemdiol Intrinsic Equilibrium

Abstract White‐light emitting organic materials have garnered significant attention due to their potential applications in lighting and display technologies. Compared to systems that emit distinct colors by combining multiple molecules, single‐molecule white‐light emission systems offer notable advantages, such as simple preparation, good repeatability and stability. In this study, a novel fluorescent molecule (BTP‐CHO) was developed. For the first time, a single‐molecule near‐white light emission system by exploiting the internal equilibrium of aldehyde‐gemdiol in water of BTP‐CHO was constructed. BTP‐CHO exists predominantly as the aldehyde form in DMSO and shows green fluorescence; while BTP‐CHO shows blue fluorescence because of the internal equilibrium of aldehyde‐gemdiol in water. Polychromatic photoluminescence could be achieved by fine‐tuning various parameters, including excitation wavelength and solvent ratio. Additionally, we synthesized three derivatives of BTP‐CHO for further investigating the universality of this strategy and the results indicate that the strategy has good universality. Finally, BTP‐CHO was successfully applied in the development of information encryption and near‐white light hydrogels. This work provides new insights into the design of organic single‐molecule white‐light emitters and broadens the scope of research on aldehyde‐gemdiol intrinsic equilibrium about white‐light emitting.