Determination of trace arsenic(V) by catalytic solid substrate-room temperature phosphorescence quenching method

In the H2SO4 medium and in the presence of dodecylbenzene sulfonic acid sodiumsalt (DBS), dimethyl yellow (R) could emit strong and stable solid substrate room temperature phosphorescence (RTP) on filter paper. And NaIO4 could oxidize R to cause the RTP quenching. Arsenic(V) could catalyze the reaction of NaIO4 oxidizing R, which caused the RTP sharply quenching. The reducing value of phosphorescence intensity (ΔIp) for the system with DBS is 3.3 times higher than that without DBS. Moreover, the ΔIp is proportional to the concentration of As(V). Based on the facts above, a new RTP quenching method for the determination of trace As(V) has been established.

Metal nanoparticle-enhanced room temperature phosphorescence of diiodofluorescein on the filter paper substrate

Metal-enhanced room temperature phosphorescence of diiodofluorescein was first observed on filter paper surface.The phosphorescence intensity is 2.5-fold brighter from diiodofluorescein on silver nanoparticles-deposited filter paper as compared with an identical control sample without silver nanoparticles.Furthermore,enhanced absorption was also observed for the same system.Our findings suggest that both singlet and triplet states can couple to surface plasmons and enhance phosphorescence quantum yields at ...

Room Temperature Phosphorescence pH Switch Based on Photo-induced Electron Transfer

In this paper, photoinduced electron transfer(PET) phosphoroionophore, N-(1-bromo- 2-naphthylmethyl)-diethanolamine (BND) was synthesized and its phosphorescent characteristics were studied. The experimental results showed that strong phosphorescence could be observed in b-cyclodextrin aqueous solution only at low pH value. This system combined AND and NOT function to produce a three-input inhibit (INH) logic gate.

Comparison of Four Deoxygenation Techniques for Cyclodextrin Induced Room Temperature Phosphorescence

The traditional deoxygenation techniques for cyclodextrin induced room temperature phosphorescence (CD-RTP) include N-2(g)purging([1]) and Na2SO3 chemical deoxygenation. In this paper, with 1-bromocyclohexane (1-BrCH) as an external heavy atom perturber, 7,8-benzoquinoline (7,8-BQ) was used as a model compound, hydrogen and carbon dioxide are used for deoxygenation in CD-RTP and compared with two traditional deoxygenation techniques. The results show that the new deoxygenation techniques have obvious advantages such as simpler facilities, faster speed of deoxygenation and wider acidity range etc.

Matrix-Mediated Color-Tunable Ultralong Organic Room Temperature Phosphorescence of 7H-Benzo[c]carbazole Derivatives

Building on the recent systematic research on 1Hbenzo[f]indole(Bd),an important advancement in constructing ultralong organic room temperature(UORTP)materials with a universal strategy via a readily obtained unit(7H-Benzo[c]carbazole,BCz)is proposed in this work.Pure powders of BCz and its derivatives merely exhibit blue fluorescence at ambient condition.However,when BCz and its derivatives are dispersed into polymer or powder matrixes,strong photo-activated green UORTP can be observed from their doped systems at room temperature.Moreover,the UORTP color can be tuned between green and yellow depending on the matrix.The ultralong phosphorescence originates from the generation of charge-separated states via radicals.The matrixes play a key role in both stabilizing charge-separated states and controlling UORTP color.More interestingly,when using polymethyl methacrylate as matrix,the doped films achieve stronger photo-activated ultralong phosphorescence underwater than in air at room temperature.Comparedwith Bd,BCz achieves better performance not only in ultralong phosphorescence properties but also in practical applications.This work gains a deeper insight into the mechanism of UORTP and paves a new approach to applying organic phosphorescent materials to underwater coating and imaging.

鞣花酸余辉气凝胶制备及光物理性质研究

以鞣花酸(EA)为发色团,将其掺杂在海藻酸钠(SA)中,经过与Zn2+、Ca2+等二价金属离子交联凝胶化,凝胶经过冷冻干燥得到绿色余辉气凝胶(EA@SA)。对EA@SA气凝胶进行光物理性能分析,结果显示,使用不同的二价金属阳离子交联的气凝胶均有良好的磷光发射,EA@SA-Zn、EA@SA-Ca、EA@SA-Sr、EA@SA-Ba气凝胶磷光寿命分别为275.71,157.59,123.92和144.56 ms,其中EA@SA-Zn气凝胶的磷光寿命最长。测试的荧光光谱及荧光寿命表明,EA@SA-Zn气凝胶的荧光发射以430 nm为发射中心,荧光寿命达到5.87 ns。SEM测试结果表明,制备的EA@SA-Zn气凝胶内部呈现网状多孔结构并且结构较为疏松,丰富的孔隙结构为EA分子提供良好的基质环境。同时,EA@SA-Zn气凝胶的元素映射图显示其表面均匀分布C、O、Zn、Cl 4种元素,这说明Zn2+与海藻酸钠交联充分,从而成功制备EA@SA-Zn气凝胶。将制备的EA@SA-Zn气凝胶放置在不同湿度环境下,随着相对湿度的增加,磷光寿命有所降低,干燥之后磷光寿命得到恢复;并且EA@SA-Zn气凝胶在乙腈(ACN)、乙醇(EtOH)、四氢呋喃(THF)、二氯甲烷(DCM)有机溶剂中均表现出良好的磷光发射,磷光寿命分别为254.76,260.14,266.64和268.67 ms。制备的EA@SA-Zn气凝胶在30 d后仍能观察到绿色余辉发射,具有磷光稳定性。最后,制备负载EA@SA-Zn气凝胶的余辉线,将其应用在刺绣和防伪领域,拓展了天然多酚制备余辉材料的策略及应用领域。

基于酰胺基取代的苯基咔唑衍生物磷光性质

用各种取代基取代咔唑已成为设计室温磷光(RTP)材料常用的分子设计策略,然而有效的取代基团仍然十分有限。本研究中,使用酰胺基团作为取代基对苯基咔唑上苯基的对位、间位和邻位进行取代,研究同分异构体间磷光性质的差异。这3种异构体晶体都表现出明亮和超长的RTP发射,在紫外光激发下分别具有长达1.02,0.76和0.89 s的超长磷光寿命,使酰胺基团成为一种新的有效的RTP促进策略。

一锅法合成可印刷室温磷光二氟化硼衍生物

纯有机室温磷光(RTP)材料因其潜在的应用价值而备受关注.迄今,多数已报道的有机RTP材料在晶态下发射出较强的RTP,但在溶液加工过程中易生成无定形态,从而失去RTP性能.本文通过一锅法两步反应,合成了含有多个甲氧基的二氟化硼衍生物(BF2-tPMO).晶体结构分析表明,多个甲氧基的存在构建了有效的分子间非共价相互作用.这些非共价键作用可抑制分子运动,保持较高的发光效率.此外,这些非共价键作用能够使其在溶剂处理后依然保持晶态性质,进而保持RTP性能.实验结果表明,BF2-tPMO可溶解在不同溶剂中且在溶剂蒸发后仍能保持相同的RTP特性,为易加工型RTP材料的设计提供了有效的策略.

Achieving purely organic room temperature phosphorescence in aqueous solution

Purely organic room temperature phosphorescence(RTP)materials have aroused increasing interests in recent years and have been widely applied in anticounterfeiting,biological imaging,sensing,etc.Currently,these materials can be efficiently developed in crystalline states and amorphous polymer-doped systems.However,achieving organic RTP in solution,especially in water solution,is still a formidable challenge.Recently,reports on aqueous phase RTP have been increasing and some feasible design strategies have been proposed;however,related investigations are still limited and there is a lack of systematic reviews.Therefore,we summarized the recent cases of aqueous phase organic RTP emission with primarily focusing on the RTP properties and efficient design strategies(e.g.,forming nanoparticles from phosphorescent molecules and macrocyclic supramolecular assembly).Moreover,promising applications of the aqueous phase organic RTP emission in bio-imaging and sensing were discussed.Some detailed perspectives concerning materials design and application were provided with the hope to provide inspiration for the future development of aqueous phase organic RTP.

How temperature and hydrostatic pressure impact organic room temperature phosphorescence from H-aggregation of planar triarylboranes and the application in bioimaging

Highly efficient persistent organic room temperature phosphorescence(RTP) has attracted increasing attention because of promising applications in fields of chemical sensors, optoelectronic devices, information security, and bioimaging, etc. Wherein,the crystal engineering of H-aggregation offers stabilization for long-lived triplet exciton for RTP, but the related research is rare because of the scarcity of ideal phosphorescent H-aggregate. Herein, we designed planar tricoordinate organoboron derivatives with molecular arrangement in ideal H-aggregation. The integration of Br atom can largely enhance RTP efficiency through increasing SOC effect, while the antiparallel molecular arrangement causes annihilation of triplet exciton. Thanks to good selfassembly property, their RTP can even be observed in PMMA matrix with doping ratio of merely 1 wt%. We further found that the cryogenic temperature contributes to stabilizing triplet exciton in H-aggregation, leading to red-shifted phosphorescence. By applying high hydrostatic pressure, the phosphorescence was largely enhanced and redshifted, demonstrating the crucial role of H-aggregation on RTP property. In phosphorescent tissue imaging of live mouse, nanoparticles of BrBA exhibited high contrast image via eliminating the interference of autofluorescence.

Colorful ultralong room-temperature phosphorescence in dual-ligand metal-organic framework

Long afterglow organic-inorganic hybrid materials have attracted much attention in recent years and are widely used in information security, biological imaging and many other fields. Since up-conversion long-persistence materials are promising for bio-optical imaging due to their high penetration depth and elimination of autofluorescence background, it is highly desirable to combine down-conversion and up-conversion pathways to obtain smart materials with excitation-dependent tunable room-temperature phosphorescence properties. In this work, a metal-organic framework(Zn-DCPS-BIMB), consisting of divalent zinc ions, o-bis(imidazol-1-ylmethyl)benzene and 4,4-dicarboxydiphenylsulfone, is designed to stabilize triplet excitons, coordinate the emission of different ligands, and endow materials with tunable emission color and up-conversion properties via heavy atoms effects promoting single-triplet orbital coupling and intersystem crossing.

A universal strategy for achieving dual cross-linked networks to obtain ultralong polymeric room temperature phosphorescence

Efficient polymeric room-temperature phosphorescence(PRTP)with excellent processability and flexibility is highly desirable but still faces formidable challenge.Herein,a general strategy is developed for efficient PRTP through photo-polymerization of phosphor monomers and N-isopropylacrylamide(NIPAM)spontaneously without a crosslinker.Remarkably ultralong lifetime of 3.54 s with afterglow duration time of 25 s and decent phosphorescent quantum efficiency of 13%are achieved.This efficient PRTP has been demonstrated to be derived from the synergistic effect of the covalent and hydrogen bonds networks formed through photo-polymerization of NIPAM.The electron paramagnetic resonance(EPR)spectra confirmed that methyl radicals are generated under the irradiation of ultraviolet light and promote the formation of covalent cross-linking networks.This strategy has also been proved to be generalizable to several other phosphor monomers.Interestingly,the polymer films display ultrahigh temperature resistance with long afterglows even at 140℃ and unexampled ultralong lifetime of 2.45 s in aqueous solutions.This work provides a simple and feasible avenue to obtain efficient PRTP.

Intrinsic persistent room temperature phosphorescence derived from 1H-benzo[f]indole itself as a guest

The influence of 1H-benzo[f]indole(Bd) and its derivatives on room temperature phosphorescence(RTP)has raised great concern since they were found to significantly affect RTP of the extensively studied carbazole(Cz) derivatives. However, the role of Bd itself existing in Cz-based or other doping systems was still unclear. In order to clarify its intrinsic phosphorescent property, Bd was introduced as a guest into different organic matrixes including substituted Cz derivatives and polymers. The phosphorescence located in 560–620 nm was confirmed to be derived from Bd itself, which can be detected whatever Bd was doped in the crystal or amorphous state of Cz derivatives. The suitable energy gap between Cz derivatives and Bd is the key to achieve ultralong RTP of Bd. Additionally, when doped in polymers with plenty of hydrogen bonds, RTP of Bd with lifetime over 280 ms was easily obtained. Among them, Bd@PHEMA(poly(hydroxyethyl methacrylate) exhibited superior phosphorescence, with yellow afterglow lasting for over 2.5 s. Therefore, this work demonstrated that a new organic RTP phosphor, Bd, is discovered, and ultralong RTP of Bd can be achieved not only doped in Cz derivatives but also in polymers as the hosts.

Multifunctional AIE Molecules Possessing Long-lasting Room Temperature Phosphorescence, Thermally Activated Delayed Fluorescence and Dual-mode Mechanochromism

Two simple donor-acceptor multifunctional pure organic light-emitting molecules[(9H-carbazol-9-yl)(4-hydroxyphenyl)-methanone(CzMP)and(4-hydroxyphenyl)(10H-phenothiazin-10-yl)methanone(PTZMP)]with distinct aggregation-induced emission(AIE)properties were synthesized.Surprisingly,CzMP showed a long room temperature phosphorescence lifetime(>900 ms),and PTZMP exhibited triple emission of prompt fluorescence(PF),room temperature phosphorescence(RTP)and thermally activated delayed fluorescence(TADF).Furthermore,CzMP effectively responded to mechanical external forces and solvent fumigation,exhibiting dual-mode mechanochromic luminescence(MCL)including multiple fluorescence color shifts and phosphorescence switching.Time-dependent density functional theory(TDDFT)calculations were investigated to explain different luminescence properties of the two molecules,and the single crystal of CzMP was obtained and analyzed to demonstrate the unique molecular stacking pattern and strong intermolecular interactions in close association with phosphorescence emission.The multifunctional luminescent properties of the emitters explored in this work could be more effectively applied to a wide range of applications,such as information encryption and anti-counterfeiting.

Room-temperature phosphorescence materials from crystalline to amorphous state

Room temperature phosphorescence(RTP)in metal-free organic materials has attracted considerable attention due to its rich excited state properties,high quantum efficiency,long luminescence lifetimes,etc.,showing great potential in organic optoelectronic devices,bioimaging,information anti-counterfeiting,and so forth.The crystals have excellent rigidity and clear molecular packing patterns,which can effectively avoid non-radiative transitions of excitons for phosphorescence enhancement.In the early stages,researchers paid great attention to the regulation of RTP performance in crystalline states.However,due to the complex preparation and poor processability of crystals,amorphous materials with RTP features have become a new research topic recently.This perspective aims to summarize the recent advances of RTP materials from crystalline to amorphous states,and analyze their molecular design strategies and luminescence mechanisms in detail.Finally,we prospect the future research directions of amorphous RTP materials.This perspective will provide a guideline for the future study of advanced RTP materials.

Ratiometric hypoxia detection by bright organic room temperature phosphorescence of uniformed silica nanoparticles in water

Organic room temperature phosphorescence(RTP)in water has attracted much attention recently for its potential biological applications.However,it remains a formidable challenge to achieve efficient RTP from pure organic compounds in aqueous phase due to the dramatic deactivation of triplet excited states in water and the poor water dispersibility of large organic particles/crystals.Represented herein is covalent incorporation of a pure organic monochromophore in silica nanoparticles(SiNPs)featuring fluorescence and bright phosphorescence in aqueous solution.The covalent bonding of organic phosphors in polysiloxane framework was found to show excellent water dispersibility,at the same time suppress the nonradiative deactivation of triplet excited states especially from water,thus leading to high phosphorescence quantum yields(up to 22%)and long lifetimes(up to 3.5 ms)in aqueous phase.More strikingly,oxygen-insensitive fluorescence as internal reference and oxygen-dependent phosphorescence as oxygen indicator from the organic chromophore in the porous SiNPs realized ratiometric hypoxia detection with ultrasensitivity(K_(SV)=449.3 bar^(-1)).

若干香豆素衍生物在滤纸基质上的RTP和RTF特性

详细考察了各种基质、重原子微扰剂和实验条件的影响之后,成功地实现了多种香豆素衍生物的室温磷光(RTP)发射。在滤纸基质上,以1mol/L的Pb(Ac)_2作重原子微扰剂时,近20种香豆素衍生物大都能产生较强的RTP发射。而且某些衍生物的RTP强度和λ_(ex)/λ_(em)等特性间呈现出明显的取代基效应。本文还对这些衍生物在滤纸基质上的室温荧光(RTF)和其混和光谱(在重原子微扰剂存在下以荧光方式测得的光谱)等特性作了对比测定,发现其间亦呈现类似的取代基效应。有关香豆素衍生物的RTP特性,迄今尚未报道。这类衍生物RTP发射的实现,预示着它们用作RTP标记物的可能性。

有机掺杂长余辉发光材料的研究进展

有机长余辉发光材料具有制备方法简单、成本低廉、可柔性化、环境友好等优点,已广泛应用于防伪、信息保密、生物成像等领域。其中,基于掺杂体系的有机长余辉发光材料,可通过调控主客体之间的配位关系,实现长余辉时间和颜色的可调性,并可在室温下制备出性能优异的长余辉发光材料,是目前有机长余辉发光材料研究的热点。该文从小分子基质体系、大分子基质体系、聚合物基质体系等方面综述了该领域的研究进展,介绍了相关材料在信息加密与防伪、生物成像、柔性纤维薄膜等领域的应用。最后,指出了目前有机掺杂长余辉发光材料在磷光寿命、余辉波长和激发波长等方面的不足,通过对有机材料长余辉发光机理的进一步完善,有望开发出性能更优,应用范围更广泛的纯有机长余辉发光材料。

Utilizing morpholine for purely organic room temperature phosphors

In this article,morpholine,a non-conjugated heterocycle,is embedded intoπsystem to construct single-component organic room temperature phosphorescence(RTP)luminogens.The effect of morpholine on intermolecular interaction,crystal packing modes,and RTP performance is investigated systematically.The experimental and theoretical calculation results illustrate the versatility of morpholine in promoting the n-π*transition and intensifying the intermolecular interactions,which not only enhances the generation of triplet excitons,but also suppresses the nonradiative decay of triplet excitons.Impressively,TMPh containing three morpholine units shows an ultralong lifetime of 1.03 s and a visible afterglow up to 10 s.The unique dual delayed emission and long afterglow property allow potential application of morpholine derivatives in data encryption,and the time-dependent color change of afterglow emission is realized after removing the excitation source,providing a high-level data security.This article provides a new perspective for the design of purely organic RTP system without utilization of metal,or even any heavy atoms.

纯有机室温磷光材料的应用

室温磷光材料由于其独特的三线态发光机理而具有Stokes位移大、激发态寿命长等特点。然而传统的室温磷光材料多含重金属原子,随之产生的生物毒性问题和环境污染问题限制了其应用。相比之下,纯有机室温磷光材料生产成本低、毒性小,可通过分子工程对有机结构进行灵活的设计和修饰,使其具有更丰富的发光特性,在防伪加密、有机电致发光、生物成像、传感检测等方面具有良好的应用前景。总结了近年来纯有机室温磷光材料在防伪与信息加密及储存、有机电致发光、生物成像、传感检测及其他应用方面的研究进展,并对纯有机室温磷光材料应用尚待解决的问题与未来可能的发展方向进行了简要总结和展望。