White light emitting molecular logic gates.

White light emitting (WLE) materials are of considerable interest with commercial and societal applications in video displays and lighting devices. A characteristic property of WLE materials is the luminescence profile spanning from 380 to 700 nm. The design of molecules, in particular, that emit white light is not so straightforward due to Kasha's rule. However, in recent years, significant progress has been made in the understanding of new photophysical mechanisms. Photochemical concepts such as excited state intramolecular proton transfer (ESIPT), twisted internal charge transfer (TICT), vibration-induced emission (VIE) and aggregation-induced emission (AIE) are among the designs in the field. Sensory molecules emitting white light remain uncommon, while those with logic-based capabilities for sensing two or more analytes or physicochemical properties, are even rarer. These latter gems are the focus of this review. Some fundamental concepts of Boolean logic are introduced for the non-expert, followed by a survey of molecular sensors and molecular logic gates that emit white light. Our aim is to introduce the reader to logic-based molecules for addressing societal challenges.