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Recently, a remarkable advance has been made for metal-free room-temperature phosphorescence (RTP) crystals with high phosphorescence quantum yield. However, amorphous, especially heavy-atom-free, RTP materials still suffer from low quantum yield due to the transition-forbidden character of phosphorescence and the relatively poor suppression of nonradiative transition in amorphous materials. In this study, a series of single-benzene structure-based high intersystem crossing yield phosphor is obtained. After embedding into polyvinyl alcohol matrix, all these phosphor exhibits efficient phosphorescence emission (Ф P , up to 44.0%). Besides, photo-switchable phosphorescence emission can be obtained by doping these molecules into a polymethyl methacrylate (PMMA) matrix. The phosphorescence can be gradually switched on by consuming the residual oxygen in the PMMA matrix under continuous UV light irradiation. Furthermore, the phosphorescence will be spontaneously switched off under ambient conditions. Taking advantage of the photoactivation character, this material has potential in information storage and anti-counterfeiting.

Pure organic room‐temperature phosphorescence (RTP) materials have attracted wide attention for their easy preparation, low toxicity, and applications in various fields like bioimaging and anti‐counterfeiting. Developing phosphorescent systems with more universality and less difficulty in synthesis has long been the pursuit of materials scientists. By employing a polymeric quaternary ammonium salt with an ionic bonding matrix and heavy atoms, commercial fluorescent dyes are directly endowed with phosphorescence emission. In a single amorphous polymer, the external heavy‐atom effect generates excited triplet states and the rigid polymer matrix stabilizes them. This study put forward a new general strategy to design and develop pure organic RTP materials starting from existing library of organic dyes without complicated chemical synthesis.

There are limited reports about the transformation of pure organic room-temperature phosphorescence (RTP) materials with multilevel stimuli-responsiveness at different RTP emission wavelengths under external stimuli. It is difficult to ensure efficient intersystem crossing (ISC) in different states of a singlecomponent system. This research reports the conversion of the organic single-component small molecule 1,2bis(4-alkoxyphenyl)ethane-1,2-dione (N-BOX) with multilevel stimuli-responsiveness between high-efficiency blue and yellow RTP by grinding or thermal annealing N-BOX crystals. The RTP emission of N-BOX in the crystalline state was easy to adjust by external stimuli (grinding or thermal annealing) due to its non-compact packing, which led to a phase transition and generated unique multilevel stimuli-responsiveness. In particular, the RTP quantum yield of 7-BOX with multilevel stimuli-responsiveness reached 68.4 %, which provides an opportunity for regulation of smart optical materials based on pure organic RTP.

Two 2D amphiphilic organoplatinum(ii) metallacycles with a porphyrin unit as the core and hydrophilic glycol units as the tail were designed and fabricated successfully through a new method called "coordination-driven self-assembly". They can self-assemble into micelles in water and have potential applications in photodynamic therapy.

It has become an accepted approach to construct room-temperature phosphorescence (RTP) materials by suppressing the non-radiative decay process. However, there is limited success in developing fluid phosphorescence materials due to the ultrafast non-radiation relaxation of vibration and collision of molecules in fluid matrixes. In this study, a universal strategy was proposed for pure organic phosphorescent fluid materials that are able to generate effective phosphorescent emissions at both room temperature (Φ RTP, 293 K 30%) and even higher temperature (Φ RTP, 358 K ~ 4.53%). Based on these findings, a qualitative analytical method was developed for leak detection and a quantitative analytical technique was further validated to help visually identify the heat distribution of irregular surfaces. This advancement greatly empowers the current organic phosphorescent system offering an alternative approach to determine moisture and heat from non-invasive photoluminescence emission colors. File list (2) download file view on ChemRxiv A Universal Strategy for Organic Fluid Phosphorescence... (661.32 KiB) download file view on ChemRxiv SI--A Universal Strategy for Organic Fluid Phosphorescen... (2.85 MiB)

A set of red-light-excited, metal-free room-temperature phosphorescence (RTP) systems were constructed by brominated phenolsulfonephthaleine derivatives. The best metal-free RTP system has the reddest near-infrared (NIR) RTP emission (λp = 819 nm) with the highest phosphorescence quantum yield (ΦRTP = 3.0%) so far as is known. The RTP emission can be switched ON-OFF by adding acid and alkali alternatively. A logic operation with half-subtractor function and dual-channel response (visible light emission/NIR RTP emission) was also constructed based on these properties mentioned above.

In this work, a universal strategy for solid, solution, or gel state organic persistent luminescent materials via radiative energy transfer is proposed. The persistent luminescence (τ>0.7 s) could be remotely regulated between different colors by controlling the isomerization of the energy acceptor. The function relies on the simple radiative energy transfer (reabsorption) mechanism, rather than the complicated communication between the excited state of the molecules such as Förster resonance energy transfer or Dexter energy transfer. And the “apparent lifetime” for the energy acceptor is the same as the lifetime of the energy donor, which was different with a traditional radiative energy transfer process. The simple working principle endows this strategy with huge universality, flexibility, and operability. This work offers a simple, feasible, and universal way to construct various persistent luminescent materials in solid, solution, and gel states.