多色有机室温磷光材料设计策略的研究进展

多色有机室温磷光(Room Temperature Phosphorescent,RTP)材料因其发射寿命长、颜色可调、生物相容性好以及激发态性质可调控等独特的性质,在显示技术、防伪、数据加密以及传感等领域展现出巨大的应用潜力,近年来受到了研究者的广泛关注。然而,受限于有机材料的三重态激子固有的敏感性,其三重态发光性质的调控成为了一个重大挑战。因此,在有机体系中实现多色且稳定的RTP发射仍然是一项亟待解决的问题。本文旨在综述近年来在多色有机RTP材料设计方面所取得的进展,重点介绍了卤素效应、晶体工程、聚集体效应以及主客体掺杂策略。通过精心选择和设计磷光分子,结合分子内/分子间相互作用和聚集态调控,成功实现了多种颜色的RTP发射。希望本文能为多色RTP材料的合理设计提供一定的思路,并为多色RTP材料的各种前沿应用提供一定的指导。

碳点三聚氰胺室温磷光材料的制备与性质

采用溶剂热法,设计合成了两种具有长寿命室温磷光的复合材料:CDs-blue@MA和CDs-yellow@MA。使用X-射线衍射(XRD)、傅里叶变换红外(FT-IR)等对复合材料的结构进行了表征,并使用荧光光谱、室温磷光光谱和时间分辨衰减磷光光谱对复合材料的性能进行了研究。结果表明,所合成的两种材料均具有良好的室温磷光性质,其中,CDs-blue@MA发射绿色室温磷光,CDs-yellow@MA发射黄色室温磷光,且它们的室温磷光寿命分别达到248.33、246.58 ms。基于此优异的长寿命室温磷光性质,CDs-blue@MA和CDs-yellow@MA在数据、图像等二级防伪与信息加密等领域展示出了较好的应用前景。

基于PBA-ETO长磷光延时的紫外/可见高对比度探测

基于有机磷光材料PBA-ETO(乙氧基苯硼酸)的室温长磷光延时这一物理特性,通过波长转换的方法实现紫外信号的探测,因材料对紫外/可见信号存在较大的延时差异,通过斩波器、单片机、外触发工业相机实现原本空间信号时间上的分离,当斩波器处于通光状态时,紫外/可见混合信号被抓拍;当斩波器处于断光状态下时,紫外信号对应的转换信号被采集,通过数字图像处理的方法,实现二者的融合。为了进一步提升成像质量,根据衍射成像相关理论,结合CCD探测器的像素尺寸,提出一种周期为200μm金属微孔阵列结构,在实现紫外/可见对比度增强的基础上,图像细节、边缘轮廓得到进一步优化。

Photoinduced Room-Temperature Phosphorescence of Triphenylamine-Phenothiazine Derivative-Doped Polymers

Photo-responsive room-temperature phosphorescent(RTP)materials have garnered significant interest due to the advantages of rapid response,spatiotemporal control,and contactless precision manipulation.However,the development of such materials remains in its infancy,underscoring the importance of exploiting novel and efficient light-responsive RTP molecules.In this work,three phenothiazine derivatives of TPA-PTZ,TPA-2PTZ,and TPA-3PTZ were successfully synthesized via the Buchwald-Hartwig C—N coupling reaction.By embedding these molecules as RTP guests into polymethyl methacrylate(PMMA)matrix,photo-induced RTP properties were realized.Upon sustained UV irradiation,there was an enhancement of 19 times in the quantum yield to reach a value of 5.68%.Remarkably,these materials exhibit superior alongside robust light and thermal stability,maintaining high phosphorescence intensity even after prolonged UV exposure(irradiation for>200 s by a 365 nm UV lamp with the power of 500μW·cm-2)or at higher temperature up to 75℃.The outstanding properties of these photo-induced RTP materials make them promising candidates for applications in information encryption,anti-counterfeiting,and advanced optical materials.

Detection of Oxygen Based on Host-Guest Doped Room-Temperature Phosphorescence Material

Quantitative oxygen detection,especially at low concentrations,holds significant importance in the realms of biology,complex environments,and chemical process engineering.Due to the high sensitivity and rapid response of the triplet excitons of phosphorescence to oxygen,pure organic room-temperature phosphorescence(RTP)materials have garnered widespread attention in recent years for oxygen detection.However,simultaneously achieving ultralong phosphorescence at room temperature and quantitative oxygen detection from pure organic host-guest doped materials poses challenges.The d ensely packed materials may decrease non-radiative decay to increase the phosphorescence,but are unsuitable for oxygen diffusion in oxygen detection.Herein,the oxygen sensitivity of host-guest doped RTP materials using 4-bromo-N,N-bis(4-(tertbutyl)phenyl)aniline(TPABuBr)as the host and 6-bromo-2-butyl-1H-benzo[de]isoquinoline-1,3(2H)-dione(NIBr)as the guest was developed.The doped material exhibits fluorescence-phosphorescence dual-emission behavior at room temperature.The tert-butyl groups in TPABuBr facilitate appropriate intermolecular spacing in the crystal state,enhancing oxygen permeability.Therefore,oxygen penetration can quench the phosphorescence emission.The observed linear relationship between the phosphorescence intensity of the doped material and the oxygen volume fraction conforms to the Stern-Volmer equation,suggesting its potential for quantitative analysis of oxygen concentration.The calculated limit of detection is 0.015%(φ),enabling the analysis of oxygen with a volume fraction of less than 2.5%(φ).Moreover,the doped materials demonstrate rapid response and excellent photostability,indicating their potential utility as oxygen sensors.This study elucidates the design and characteristics of NIBr/TPABuBr doped materials,highlighting their potential application in oxygen concentration detection and offering insights for the design of oxygen sensors.

Different molecular conformation and packing determining mechanochromism and room-temperature phosphorescence

The phenomenon that different molecular packing modes in aggregates result in different optical properties has attracted intense attention,since it can provide useful information to establish the relationship between the micro-and macro-world.In this paper,DBTDO-DMAC was designed with 9,10-dihydro-9,9-dimethylacridine(DMAC)as electron donor.DBTDO-DPA and DBTDO-Cz were designed for comparison,which adopted diphenylamine(DPA)with twisted structure and carbazole(Cz)with planar structure as donors,respectively.As expected,two polymorphs(Crystal G and Crystal Y)of DBTDO-DMAC were obtained and exhibited distinct properties.Crystal G originating from planar conformation exhibited mechanochromism(MC)phenomenon and the emission color changed from green to yellow with a redshift of 35 nm after grinding.Nevertheless,Crystal Y with folded conformation displayed obvious room-temperature phosphorescence(RTP)with yellow afterglow.Careful single crystal analyses,powder X-ray diffraction and theoretical calculation reveal that the different emissive behaviors are highly related to the molecular conformation and packing modes.The successful adjustment of molecular conformation provides some guidance in the design of other MC and/or RTP luminogens,broadens the molecule family with the tunable molecular conformation and opens up a new avenue for exploring possible adjustment of molecular packing in aggregates.

Biocompatible metal-free organic phosphorescent nanoparticles for efficiently multidrug-resistant bacteria eradication

Organic phosphorescence materials with longlived triplet excitons that can highly generate active singlet oxygen(1O2) through the energy transfer with the molecular oxygen under photoexcitation, serve as highly efficient antibacterial agent. Herein, we report bright red-emissive organic phosphorescent nanoparticles(PNPs) based on a metal-free organic phosphor encapsulated with biocompatible block copolymers. The obtained PNPs with an ultra-small particle size of around 5 nm and a long emission lifetime of up to 167 μs showed effective 1O2 generation ability under visible light(410 nm) excitation in aqueous media, which can efficiently eradicate multi-drug resistant bacteria both in vitro and in vivo. This is the first demonstration of metal-free organic PNPs for photodynamic antimicrobial therapy, expanding the application scope of metal-free organic room temperature phosphorescent materials.