Research on materials with pure organic room temperature phosphorescence (RTP) and their application as organic single-molecule white light emitters is a hot area and relies on the design of highly efficient pure organic RTP luminogens. Herein, a facile strategy of heavy-atom-participated anion–π+ interactions is proposed to construct RTP-active organic salt compounds (1,2,3,4-tetraphenyloxazoliums with different counterions). Those compounds with heavy-atom counterions (bromide and iodide ions) exhibit outstanding RTP due to the external heavy atom effect via anion–π+ interactions, evidently supported by the single-crystal X-ray diffraction analysis and theoretical calculation. Their single-molecule white light emission is realized by tuning the degree of crystallization. Such white light emission also performs well in polymer matrices and their use in 3D printing is demonstrated by white light lampshades.

A novel AIEgen with prominent two-photon excitation was rationally developed for specific lipid-droplet imaging in cells and tissues.

With recent progress in photothermal materials, organic small molecules featured with flexibility, diverse structures, and tunable properties exhibit unique advantages but have been rarely applied in solar‐driven water evaporation owing to limited sunlight absorption resulting in low solar–thermal conversion. Herein, a stable croconium derivative, named CR‐TPE‐T, is designed to exhibit the unique biradical property and strong π–π stacking in the solid state, which facilitate not only a broad absorption spectrum from 300 to 1600 nm for effective sunlight harvesting, but also highly efficient photothermal conversion by boosting nonradiative decay. The photothermal efficiency is evaluated to be 72.7% under 808 nm laser irradiation. Based on this, an interfacial‐heating evaporation system based on CR‐TPE‐T is established successfully, using which a high solar‐energy‐to‐vapor efficiency of 87.2% and water evaporation rate of 1.272 kg m−2 h−1 under 1 sun irradiation are obtained, thus making an important step toward the application of organic‐small‐molecule photothermal materials in solar energy utilization.

Recent years have witnessed the significant role of anion-π interactions in many areas, which potentially brings the opportunity for the development of aggregation-induced emission (AIE) systems. Here, a new strategy that utilized anion-π interactions to block detrimental π-π stacking was first proposed to develop inherent-charged AIE systems. Two AIE-active luminogens, namely, 1,2,3,4-tetraphenyloxazolium (TPO-P) and 2,3,5-triphenyloxazolium (TriPO-PN), were successfully synthesized. Comprehensive techniques such as single-crystal analysis, theoretical calculation, and conductivity measurement were used to illustrate the effects of anion-π interactions on the AIE feature. Their analogues tetraphenylfuran (TPF) and 2,4,5-triphenyloxazole (TriPO-C) without anion-π interactions suffered from the aggregation-caused emission quenching in the aggregate state, demonstrating the important role of anion-π interactions in suppressing π-π stacking. TriPO-PN was biocompatible and could specifically target lysosome in fluorescence turn-on and wash-free manners. This suggested that it was a promising contrast agent for bioimaging.

A novel mitochondrion-specific photo-activatable fluorescence turn-on bioprobe, named as o-TPE-ON+, is designed and readily prepared, operating through a new photoactivatable mechanism of photocyclodehydrogenation. This bioprobe exhibits unique photoactivation behavior in cells, and is applied to super-resolution imaging of mitochondrion and its dynamic investigation in both fixed and live cells under physiological conditions without any external additives.

A new convenient and continuous fluorometric assay method for acetylcholinesterase (AChE) and its inhibitor screening is successfully established with the ensemble of 1 [a TPE (tetraphenylethylene) compound with two sulfonate (-SO(3)(-)) units] and myristoylcholine (an amphiphilic compound as a good substrate of AChE). This new assay method is designed by making use of the aggregation-induced emission (AIE) feature of TPE compounds. Both dynamic light scattering (DLS) and fluorescence confocal microscopic measurements indicated the formation of aggregation complex for the ensemble of 1 and myristoylcholine and further disassembly of the aggregation complex after introducing AChE. The analysis for AChE can be carried out continuously, and AChE with concentration as low as 0.5 U/mL can be assayed. The results also clearly demonstrate the usefulness of this convenient assay method for kinetic study of AChE-catalyzed myristoylcholine hydrolysis and screening inhibitors of AChE. Given its simplicity and easy operation, this method may extend to high-throughput screening of AChE inhibitors and relevant Alzheimer's disease (AD) drug discovery.

The synthesis and optical investigations of di(p‐methoxylphenyl)dibenzofulvene (1) and its analogues 2, 3, 4, 5, 6, and 7 with different lengths of alkoxyl chains are presented. All of these molecules exhibit emission in the solid state. The following interesting properties are reported for compound 1: 1) the solid‐state fluorescence of 1 is dependent on the polymorphism forms; the two crystalline forms 1a and 1b are strongly blue‐ and yellow‐green‐emissive, whereas the amorphous solid is weakly fluorescent with orange emission; 2) on the basis of crystal‐structural analysis, the intermolecular interactions will restrict the internal rotations, leading to fluorescence enhancement for the two crystalline forms 1a and 1b; however, the difference in emission color between 1a and 1b is ascribed to the molecular conformational alteration; 3) the solid‐state fluorescence of 1 can be tuned by heating and cooling as well as grinding. Importantly, microrods of 1a and 1b exhibit outstanding optical waveguide behaviors. Moreover, amplified spontaneous emission for 1b and multimode‐lasing behavior for 1a are presented. Besides the studies of compound 1, the crystal structures and solid‐state fluorescence behaviors of 2, 3, 4, 5, 6, and 7 are also described.

Photocyclized intermediate formation and quasi CC twisting are the dominant processes behind the AIE.