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.

Recent Advances in Pure-Organic Host-Guest Room-Temperature Phosphorescence Systems Toward Bioimaging

Organic room-temperature phosphorescence(RTP)materials have garnered considerable attention in the fields of biosensing,optoelectronic devices,and anticounterfeiting because of their substantial Stokes shifts,tunable emission wavelengths,and prolonged lifetimes.These materials offer remarkable advantages for biological imaging applications by effectively reducing environmental autofluorescence and enhancing imaging resolution.Recently,host-guest systems have been employed as efficient approaches to fabricate pure-organic RTP materials for bioimaging,providing benefits such as controllable preparation and flexible modulation.Consequently,an increasing number of corresponding studies are being reported;however,a comprehensive systematic review is still lacking.Therefore,we summarize recent advances in the development of pureorganic RTP materials using host-guest systems with regard to bioimaging,including rigid matrices and sensitization.The challenge and potential of RTP for biological imaging are also proposed to promote the biomedical applications of organic RTP materials with excellent optical properties.

Study on Room-Temperature Phosphorescence of 1-Bromonaphthalene in Media of Surfactant and β-Cyclodextrin

Sdrictants(S) induced room-ternperature phorphorescence(RTP) frorn l-bromonaplithalene(l-BrN) in aerated aqueous solutions of o-cyclodextha(β-CD) hasbeco mvestigated m detail. lt has been fotmd that the partial incIu5ion and coil ofhydIocarbon chain of edctans at the mouth of the 6-CD ca\4ty' is reSPoedle foTbright RTP

Room-Temperature Phosphorescence and Lifetime of Fossil Resins (Amber) from Dominican Republic, Mexico, Baltic Sea, Myanmar, and Fushun, China

Amber can emit room temperature phosphorescence(RTP)under the well-known 365 nm fluorescence ultraviolet light.This paper is devoted to the phosphorescence study of 20 pieces of amber materials from the Dominican Republic,Mexico,Baltic sea,Myanmar,and Fushun,China.The results show that amber from the same geographic origin has similar shape in phosphorescence spectra.However,the shape of the amber phosphorescence spectra varies depending on their different localities.Burmite(amber from Myanmar)and Fushun amber have a bright yellow phosphorescence with a long lifetime,while the Dominican and Mexican ones are weaker and last shorter.The irradiation of Baltic amber becomes faint or even inert.Phosphorescence spectral Gaussian fitting results suggest an emission maximum near 550 nm in most amber samples.Their phosphorescence lifetime,analyzed through the exponential function fitting,is up to 1 second in Burmite and Fushun samples,shorter in the Dominican and Mexican ones,about 0.230 s,and the shortest in Baltic amber,close to 0.151 s.These variations of phosphorescence lifetime and intensity are related to the relative geological ages of these amber.It indicated that the phosphorescence agent was probably formed during the long geological time.While the anomaly occurred in Baltic amber,the only one found in a sea secondary deposit form,it demonstrated that the terrestrial geological environment these amber preserved has prevented the phosphorescence agent to be deactivated.

A new insight into aggregation structure of organic solids and its relationship to room-temperature phosphorescence effect

In order to improve the performance of organic luminescent materials,lots of studies have been carried out at the molecular level.However,these materials are mostly applied as solids or aggregates in practical applications,in which the relationship between aggregation structure and luminescent property should be paid more attention.Here,we obtained five phenothiazine 5,5-dioxide(O-PTZ)derivatives with distinct molecular conformations by rational design of chemical structures,and systematically studied their room-temperature phosphorescence(RTP)effect in solid state.It was found that O-PTZ dimers with quasi-equatorial(eq)conformation tended to show strongerπ-πinteraction than quasi-axial(ax)conformers in crystal state,which was more conducive to the generation of RTP.Based on this result,a multi-level structural model of organic solids was proposed to draw the relationship between aggregation structure and RTP effect,just like the research for the structureproperty relationship of proteins.Using this structural model as the guide,boosted RTP efficiency from 1%to 20%was successfully achieved in the corresponding host-guest doping system,showing its wide applicability.

Solid-state room-temperature phosphorescence activated by the end-capping strategy of cyano groups

Avoiding the tedious process of crystal cultivation and directly obtaining organic crystals with desirable phosphorescent performance is of great significance for studying their structure and properties.Herein,a set of benzophenone-cored phos-phors with bright green afterglow are obtained on a large scale through in-situ generation via an end-capping strategy to suppress non-radiative triplet excitons and reinforce the intermolecular interactions.The ordered arrangement of phosphors with alkyl-cyano groups as regulators is crucial for the enhancement of room-temperature phosphorescence(RTP)emission,which has been further verified by the attenuated lifetimes in isolated states through the formation of inclusion complexes upon binding with pillar[5]arenes.Moreover,the hierarchical interactions of phos-phors,including hydrogen bonding,π-πstacking interactions,and van der Waals forces,are quantified by crystal structures and theoretical calculation to deeply inter-pret the origins of RTP emission.With this study,we provide a potential strategy for the direct acquisition of crystalline organic phosphors and modulation of RTP.

Responsive organic room-temperature phosphorescence materials for spatial-time-resolved anti-counterfeiting

Stimulus-responsive room-temperature phosphorescence(RTP)materials have gained significant attention for their important optoelectronic application prospects.However,the fabrication strategy and underlying mechanism of stimulus-responsive RTP materials remain less explored.Herein,we present a reliable strategy for achieving pH-responsive RTP materials by integrating poly(vinyl alcohol)(PVA)with carboxylic acid or amino group functionalized terpyridine(Tpy)derivatives.The resulting Tpy derivativesbased RTP materials displayed reversible changes in emission color,intensity,and lifetime of both prompt and delayed emission.Notably,the RTP emission undergoes a significant diminish upon exposure to acid due to the protonation of Tpy units.Taking advantage of the decent RTP emission and pH-responsiveness of these RTP films,a spatial-time-resolved anti-counterfeiting application is demonstrated as a proof-ofconcept for largely enhancing the security level.This study not only provides new prospects for developing smart RTP materials but also promotes the advancement of optical anti-counterfeiting applications.

Photoactivated Circularly Polarized Room-Temperature Phosphorescence from Phenoselenazine Derivative and Its Application in Information Security

Room-temperature phosphorescence(RTP)materials have experienced rapid development due to their potential in organic light-emitting diode,information security,bioimaging,etc.However,the design of chiral organic phosphors with circularly polarized RTP(CPP)property remains a formidable challenge.Here,we introduce a chiral perturbation approach using a combination of chiral binaphthol and phenoselenazine derivative to achieve CPP.The photoactivated CPP in polystyrene(PS)film demonstrates a luminescence dissymmetry factor(glum),emission efficiency,and RTP lifetime up to 9.32×10^(–3),27.0%,and 40.0 ms,respectively.The remarkable sensitivity of PS film to oxygen and temperature enables the adjustable emission colors,ranging from green to offwhite and blue under varying conditions.The doping systems,utilizing hosts of triphenylphosphine and 9-phenylcarbazole,demonstrate an extended CPP lifetime of 85.9 ms and exhibit a persistent mechanoluminescence property with low pressure response threshold as low as 0.15 N.The information security provided by this CPP material was attained via the using of diverse emission colors and afterglow generated by distinct UV irradiation times and host materials.Alternately,it can also be achieved by observing different emission patterns using R-and L-polarizer.The research has presented a reliable approach for producing CPP materials with high emission efficiency and glum.

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.

Hydrogen-Bonded Supramolecular Network Triggers High-Efficiency Blue Room-Temperature Phosphorescence

Hydrogen bonding has been employed to suppressnonradiative decay in organic compounds that showroom-temperature phosphorescence (RTP);however, the small number of structurally diverse examplesmakes it unclear how general this strategy is to turnon RTP. In this study, we report highly efficient blueRTP from 4,4′,4′′-nitrilotribenzoic acid (TPA-CO_(2)H)in five structurally and chemically distinct hydrogenbonded supramolecular networks. In doped films inpoly(vinyl alcohol) (PVA), the phosphorescencequantum yield and lifetime (ΦPh and τPh) reach 52%and 275 ms. Boric acid can also be used to turn onRTP, and the performance changes significantlywhen the sample is heated beyond the dehydrationtemperature of this host where there is a 14-foldenhancement in the ΦPh after heat treatment. BlueRTP similar to that observed in PVA was also observed using granulated sugar, gelatine, and paper ashost matrices. This work elucidates for the first timethe role and the generality of hydrogen bonding inactivating efficient blue RTP and examines how thechoice of hydrogen bonding host influences RTPperformance. We further demonstrate how the emission color can be tuned by codoping the films withRhodamine 6G.

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.

The Current Progress and Challenges of Carbonized Polymer Dot-Based Room-Temperature Phosphorescent Materials

Carbonized polymer dots(CPDs)as one type of carbon dots have attracted widespread attention in recent years.The proposal of the“shell–core”structure of CPDs leads to further thinking about the association between their special structures and luminescent properties.In recent years,great progress has been made in the field of CPD-based room-temperature phosphorescent materials.This review pays particular attention to how the special“core–shell”structure of CPDs influences the activation of roomtemperature phosphorescence(RTP).The strategies and vital factors to activate RTP for CPD-based materials in both solid state and water were reviewed in detail to elaborate on the effect of the special structure on RTP generation.Furthermore,some perspectives on the current challenges were also provided to guide the further development of CPD-based room-temperature phosphorescent materials.

Multi-modal anti-counterfeiting and encryption enabled through silicon-based materials featuring pH-responsive fluorescence and room-temperature phosphorescence

Nano Research volume 13,pages1614–1619(2020)Cite this article 236 Accesses Metrics details Abstract Optical silicon(Si)-based materials are highly attractive due to their widespread applications ranging from electronics to biomedicine.It is worth noting that while extensive efforts have been devoted to developing fluorescent Si-based structures,there currently exist no examples of Si-based materials featuring phosphorescence emission,severely limiting Si-based wide-ranging optical applications.To address this critical issue,we herein introduce a kind of Si-based material,in which metal-organic frameworks(MOFs)are in-situ growing on the surface of Si nanoparticles(SiNPs)assisted by microwave irradiation.Of particular significance,the resultant materials,i.e.,MOFs-encapsulated SiNPs(MOFs@SiNPs)could exhibit pH-responsive fluorescence,whose maximum emission wavelength is red-shifted from 442 to 592 nm when the pH increases from 2 to 13.More importantly,distinct room-temperature phosphorescence(maximum emission wavelength:505 nm)could be observed in this system,with long lifetime of 215 ms.Taking advantages of above-mentioned unique optical properties,the MOFs@SiNPs are further employed as high-quality anti-counterfeiting inks for advanced encryption.In comparison to conventional fluorescence anti-counterfeiting techniques(static fluorescence outputs are generally used,thus being easily duplicated and leading to counterfeiting risk),pH-responsive fluorescence and room-temperature phosphorescence of the resultant MOFs@SiNPs-based ink could offer advanced multi-modal security,which is therefore capable of realizing higher-level information security against counterfeiting.

A facile and green strategy to obtain organic room-temperature phosphorescence from natural lignin

Seeking pure organic functional luminescent materials that are processed from green, low-cost, and sustainable resources remains a challenging but beneficial task. As an abundant natural polymer composed of crosslinked phenol ether units, lignin is a potential source of organic luminescent material because of the presence of extensive aromatic fragments. In the present work, a remarkable afterglow involving room-temperature phosphorescence(RTP) was achieved via simply embedding alkalized lignin into polyvinyl alcohol(PVA) matrix, and an ultralong luminescence lifetime of more than 160 ms was observed. More importantly, our study revealed that small fragments of hydrolyzed lignin(named LA-H) bearing extensive phenolic oxygen anions were the effective luminescent species. When embedded into a PVA matrix, LA-H showed remarkably high luminescence quantum yield and long lifetime of RTP emission compared with those of unprocessed lignin. Additionally, the various phenol oxygen anion moieties endowed LA-H with an excitation-dependent characteristic: the color-tunable RTP could be simply tuned from a maximum emission wavelength of 434–532 nm via altering the excitation wavelength. Thus, the color-tunable afterglow of emissive LA-H could be facilely obtained with a yield up to 38.4% using simple acid hydrolysis of lignin without other complex synthesis procedures. This work opens new avenues in the large-scale preparation of low-cost and sustainable pure organic RTP materials.

Photo-controllable room-temperature phosphorescence of organic photochromic polymers based on hexaarylbiimidazole

Pure organic room-temperature phosphorescent(RTP)materials have been attracting widespread attention due to the unique properties and broad applications.However,RTP materials with the adjustable photochromic property are still a challenge.Based on this,two polymers containing hexaarylbiimidazole are strategically designed with dual emission of both fluorescence and phosphorescence.Furthermore,both polymers show sensitive photochromic responses from faint yellow to brown upon exposure to ultraviolet light.This study can enrich pure organic luminescent systems and provide new ideas for functional RTP materials.

Tunable room-temperature phosphorescence and circularly polarized luminescence encoding helical supramolecular polymer

Supramolecular polymers with different functionalities have been continuously developed in the past decade because of their indispensable role in soft materials.However,pure organic supramolecular polymers with stable room temperature phosphorescence(RTP)emission were very rarely reported for the difficulties of synthesis and achieving RTP in solution.Herein,soluble helical supramolecular polymers with circularly polarized room-temperature phosphorescence were developed via a facile hostguest strategy.Through assembly,a transition from pure fluorescence to almost pure RTP emission was achieved.Adjusting the asymmetry of guest could easily control the chiroptical property of supramolecular polymers.This work provides new opportunities for the design and development of intelligent soft functional soft materials.

Long-Lived Room-Temperature Phosphorescence Based on Hydrogen Bonding Self-Assembling Supramolecular Film

Comprehensive Summary Organic room-temperature phosphorescence(ORTP)materials have attracted widespread attention in the fields of OLED,optical imaging and sensors.Herein,we successfully prepared a long afterglow IPA-MA crystalline films using/so-phthalic acid(IPA)and melamine(MA)by a simple drop-casting layer-by-layer(LBL)method,which achieved an ultra-long emission lifetime of up to 1.15 s.

Organic Host-Guest Materials with Bright Red Room-Temperature Phosphorescence for Persistent Bioimaging

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.

Room-temperature phosphorescence from purely organic materials

Room-temperature phosphorescence（RTP） materials have attracted great attention due to their involvement of excited triplet states and comparatively long decay lifetimes.In this short review,recent progress on enhancement of RTP from purely organic materials is summarized.According to the mechanism of phosphorescence emission,two principles are discussed to construct efficient RTP materials：one is promoting intersystem crossing（ISC） efficiency by using aromatic carbonyl,heavyatom,or/and heterocycle/heteroatom containing compounds;the other is suppressing intramolecular motion and intermolecular collision which can quench excited triplet states,including embedding phosphors into polymers and packing them tightly in crystals.With aforementioned strategies,RTP from purely organic materials was achieved both in fluid and rigid media.

Influence of the alkyl side chain length on the room-temperature phosphorescence of organic copolymers

Pure organic room-temperature phosphorescence(RTP)materials have attracted wide attention owing to their excellent luminescent properties and great potential in various applications.In this work,iminostilbene and its analogues are applied to realize RTP emission by copolymerizing with acrylamide.It can be concluded that the growth of alkane chain in monomers can enhance the lifetime and photoluminescence quantum yield of RTP emission,and polymers with the larger conjugated structure of the monomer show a longer RTP emission wavelength.This work provides a series of new pure organic RTP materials and might provide new thoughts for designing more advanced and superior RTP materials.