Triarylphosphine-based pure organic long persistent luminescence materials are rarely investigated because of their poor stability and low photoluminescence quantum yield. Herein, we demonstrate that the introduction of a methoxy group (TPP-o-3OMe) at the ortho position of triphenylphosphine (TPP) can essentially promote the n → π* transition and promote intersystem crossing to generate more triplet excitons. Simultaneously, generating abundant intramolecular and intermolecular hydrogen bonds to stable excited triplet excitons is beneficial, thereby causing high-efficiency phosphorescence emission (τp = 394.1 ms; Φp = 9.28%). Interestingly, it shows a good acid response to protonic acids and can often be cycled many times under the heating or ammonia fumigation conditions. This research provides a new idea for enriching the types of pure organic room-temperature phosphorescent materials, widening their applications in the fields of anticounterfeiting and smart response, and promotes the further development of this field.

As intelligent probes, dynamic and controllable molecular switches are useful tools for probing and intervening in life processes. However, the types and properties of molecular switches are still relatively single and often can only make two actions: “off” and “on”. Therefore, the development of novel molecular switches with multiple colors and multiple instructions is very challenging. Herein, we propose a novel strategy based on the instability of the Lewis acid–base pair (boron (B) and nitrogen (N)), such as introducing the Schiff base (CN) group into the aminoborane skeleton and preparing the novel molecular switches BN-HDZ and BN-HDZ-N. These two molecules were found to have good multicolor fluorescence switching capability for methanol. Surprisingly, the compound BN-HDZ-N shows unprecedented visual identification for the butanol isomers and could be made into a portable strip for simple and rapid visual identification of the four isomers of butanol, promising an alternative to conventional Lucas reagents. This provides a novel strategy for the design and fabrication of novel multicolor-tunable molecular switches with visual identification of isomers.