Ultralong Organic Phosphorescence Modulation of Aromatic Carbonyls and Multi‐Component Systems

Comprehensive Summary Organic room‐temperature phosphorescence (RTP) materials have attracted immense attention in bioimaging due to their long emission lifetime and large Stokes shift. RTP materials with long emission wavelength can improve the penetration depth for bioimaging. However, the design of red persistent RTP materials is still challenging. In this study, a fused‐ring structure has been proposed to effectively decrease the triplet energy level, thus extending the emission wavelength of phosphorescence. In addition, the fused‐ring structure exhibits a high molar extinction coefficient (ɛ) and high luminescence efficiency due to the rigid structure. A new class of crystalline hosts (iminodibenzyl, IDB) are developed to stabilize the triplet excitons that are generated from the fused‐ring molecules. The maximum RTP wavelength of doping materials can reach 635 nm with a lifetime of 9.35 ms. Water‐disperse nanoparticles are successfully prepared for in vivo time‐resolved bioimaging, which eliminates the background fluorescence interference from biological tissues. These reveal a delicate design strategy for the construction of long‐wavelength emissive RTP materials for high‐resolution bioimaging.

Section: Background and Originality Contentmentioning

confidence: 99%

Organic Host‐Guest Materials with Bright Red Room‐Temperature Phosphorescence for Persistent Bioimaging^†

Zhao

Dai

et al. 2023

“…[ 14‐16 ] Generally, organic luminogens in a single component seldom exhibit persistent phosphorescence at ambient conditions due to their intrinsic spin‐forbidden intersystem crossing (ISC) from the lowest single state (S 1 ) to the triplet state (T n ) as well as their ultrafast triplet exciton deactivation. Tremendous endeavors, including the introduction of heteroatoms, [ 17‐18 ] heavy halogen atoms, [ 3,19 ] sulfonyl groups, [ 14 ] keto groups, [ 20‐23 ] and multimers, [ 24‐26 ] have been made to enhance the ISC efficiency and populate triplet excitons, successfully turn on the persistent phosphorescence of pure organic luminogens. Nevertheless, most of them turn on RTP relying on highly ordered crystalline structures.…”

Section: Background and Originality Contentmentioning

confidence: 99%

Ultralong Organic Phosphorescence of Triazatruxene Derivatives for Dynamic Data Encryption and Anti‐counterfeiting

Liang

Liu

et al. 2023

Comprehensive SummaryOrganic luminogens with persistent room temperature phosphorescence (RTP) have drawn tremendous attentions due to their promising potentials in optoelectronic devices, information storage, biological imaging, and anti‐counterfeiting. In this work, six triazatruxene‐based lumiogens with different peripheral substituents and configurations are synthesized and systematically studied. The results show that their fluorescence quantum yields in solid states range from 15.73% to 37.58%. Dispersing the luminogens as guest into the host (PPh3) could turn on the persistent RTP, where PPh3 acts as not only a rigid matrix to suppress the non‐radiative transitions of the guest, but also provides energy transfer channels to the guest. The maximum phosphorescence efficiency and the longest lifetime could reach 29.35% and 0.99 s in co‐crystal films of 6‐TAT‐CN/PPh3 and 5‐TAT‐H/PPh3, respectively. Moreover, these host‐guest co‐crystalline films exhibit great potentials in advanced dynamic data encryption and anti‐counterfeiting. This work deepens the insight for low cost, halogen‐free, and facile fabrication of all‐organic persistent RTP materials.

“…Dopant‐matrix design strategies developed by us and others have shown that organic matrices can modulate the triplet excited state properties of luminescent dopants for the fabrication of high‐performance organic RTP materials. [ 14,22‐38 ] Glassy or crystalline matrices have been found to provide rigid microenvironments for luminescent dopants to inhibit nonradiative decay of dopants’ triplet excited states. [ 22‐23 ] Hydrogen bonding between matrices and dopants can also significantly reduce nonradiative decay of the triplet excited states of luminescent dopants.…”

Section: Background and Originality Contentmentioning

confidence: 99%

Cascade Synthesis of Luminescent Difluoroboron Diketonate Compounds forRoom‐TemperatureOrganic Afterglow Materials

Wang

Zhao

et al. 2022

Difluoroboron β-diketonate (BF 2 bdk) compounds represent an important class of luminescent materials, whereas their synthesis requires multiple steps, which restrict their application in diverse fields. Here we report a cascade reaction to prepare BF 2 bdk from aromatic ketones, carboxylic acids, trifluoroacetic anhydride and boron trifluoride diethyl etherate. The cascade reaction is very simple and straightforward to produce BF 2 bdk with desired functional groups in reasonable isolation yields. Further, when some specific BF 2 bdk compounds are used as luminescent dopants, organic room-temperature phosphorescence with lifetimes > 1.0 s and intense afterglow under ambient conditions can be achieved with the assistance by suitable organic matrices. The dopant-matrix materials exhibit excellent processability into desired patterns and large-area panels, and function as efficient donors of excited state energy transfer for the fabrication of red afterglow materials. The materials can be processed into aqueous afterglow dispersion that displays unique property of escaping the interference from strong fluorescence background.