Room-temperature phosphorimetry studies of some addictive drugs following dansyl chloride labelling

A room-temperature phosphorimetric (RTP) method for the analysis of barbital, codeine, morphine and practolol after labelling with dansyl chloride (DNS-Cl) is described. The drug-DNS derivatives were obtained by refluxing with drug-ethyl acetate solutions and solid DNS-Cl in the presence of anhydrous potassium carbonate. The reaction conditions were investigated in detail. The fluorescence emission of drug-DNS derivatives shifted to longer wavelengths compared with that of DNS-Cl. The RTP phenomena observed for these derivatives by using a micellar stabilized room-temperature phosphorescence technique were examined and optimum conditions for their RTP emission were studied using an orthogonal array design. Derivative RTP spectra were obtained and successfully used to determine practolol by the established method without further separation.     

Carbon Dots with Dual-Emissive,Robust, and Aggregation-Induced Room-Temperature Phosphorescence Characteristics

Carbon dots (CDs) with dual-emissive, robust, and aggregation-induced RTP characteristics are reported for the first time. The TA-CDs are prepared via hydrothermal treatment of trimellitic acid and exhibit unique white prompt and yellow RTP emissions in solid state under UV excitation (365 nm) on and off, respectively. The yellow RTP emission of TA-CDs powder should be resulted from the formation of a new excited triplet state due to their aggregation, and the white prompt emission is due to their blue fluorescence and yellow RTP dual-emissive nature. The RTP emission of TA-CDs powder was highly stable under grinding, which is very rare amongst traditional pure organic RTP materials. To employ the unique characteristics of TA-CDs, advanced anti-counterfeiting and information encryption methodologies (water-stimuli-response producing RTP) were preliminarily investigated.     

Carbon Dots with Dual‐Emissive,Robust, and Aggregation‐Induced Room‐Temperature Phosphorescence Characteristics

Carbon dots (CDs) with dual‐emissive, robust, and aggregation‐induced RTP characteristics are reported for the first time. The TA‐CDs are prepared via hydrothermal treatment of trimellitic acid and exhibit unique white prompt and yellow RTP emissions in solid state under UV excitation (365 nm) on and off, respectively. The yellow RTP emission of TA‐CDs powder should be resulted from the formation of a new excited triplet state due to their aggregation, and the white prompt emission is due to their blue fluorescence and yellow RTP dual‐emissive nature. The RTP emission of TA‐CDs powder was highly stable under grinding, which is very rare amongst traditional pure organic RTP materials. To employ the unique characteristics of TA‐CDs, advanced anti‐counterfeiting and information encryption methodologies (water‐stimuli‐response producing RTP) were preliminarily investigated.     

香豆素衍生物在数种薄层基质上的室温磷光发射特性

考查了二十多种香豆素衍生物在国产ＭＮ－Ｐ型和ＭＮ－Ｃ型微晶纤维素膜，ＤＥＡＥ离子交换膜上的室温磷光发射特性，并与用滤纸作基质时的结果作了比较。在这些基质上，多数衍生物都能发射不同强度的ＲＴＰ信号，且在其ＲＴＰ特性间呈现，某些取代基效应。从发光稳定性和信背比考虑，ＭＮ－Ｃ型比ＭＮ－Ｐ型膜更适合于这些衍生物的ＲＴＰ发射。     

Molecular Engineering for Metal-Free Amorphous Materials with Room-Temperature Phosphorescence

Materials displaying room-temperature phosphorescence (RTP) have been attracting wide attention in recent years due to their distinctive characteristics including long emissive lifetime and large Stokes shift, and their various applications. Most synthesized RTP materials are metal complexes that display enhanced intersystem crossing and crystallization is a common way to restrict nonradiative transition. Amorphous metal-free RTP materials, which do not rely on expensive and toxic metals and can be prepared in a straightforward fashion, have become an important branch of the field. This Minireview summarizes recent progress in amorphous RTP materials according to the approaches used to immobilize phosphors: host–guest interactions, molecule doping, copolymers, and small-molecule self-assembly. Some existing challenges and insightful perspectives are given at the end of the Minireview, which should benefit the future design and development of amorphous metal-free RTP materials.     

Self‐Stabilized Amorphous Organic Materials with Room‐Temperature Phosphorescence

The stability of pure organic room‐temperature phosphorescent (RTP) materials in air has been a research hotspot in recent years. Without crystallization or encapsulation, a new strategy was proposed to obtain self‐stabilized organic RTP materials, based on a complete ionization of a photo‐induced charge separation system. The ionization of aromatic phenol 4‐carbazolyl salicylaldehyde (CSA) formed a stable H‐bonding anion–cation radical structure and led to the completely amorphous CSA‐I film. Phosphorescent lifetimes as long as 0.14 s at room temperature and with direct exposure to air were observed. The emission intensity was also increased by 21.5‐fold. Such an amorphous RTP material reconciled the contradiction between phosphorescence stability and vapor permeability and has been successfully utilized for peroxide vapor detection.     

Mononuclear aggregation-induced emission (AIE)-active gold(Ⅰ)-isocyanide phosphors: Contrasting phosphorescent mechanochromisms and effect of halogen substitutions on room-temperature phosphorescence nature

Developing phosphors with long-lifetime(millisecond scale or even longer) solid state room temperature phosphorescence(RTP) feature has attracted considerable attention. However, to date, stimuli-responsive phosphors with RTP nature are still rare due to the absence of effective guidelines for the exploitation of luminophors synchronously possessing stimuli-responsive and RTP characteristics. In this work,a series of mononuclear gold(Ⅰ) complexes are reported. All these complexes exhibit various...     

Luminescence characteristics of dibenzofuran and several polychlorinated dibenzofurans and dibenzo-p-dioxins

The room-temperature fluorescence (RTP), low-temperature phosphorescence (LTP) and room-temperature phosphorescence (RTP) characteristics of dibenzofuran and several polychlorinated dibenzofurans and dibenzo-p-dioxins are presented and are shown to be suitable for the determination of these compounds. The limits of detection are as low as 0.02, 0.2 and 0.7 for RTF, LTP and RTP, respectively. The relative standard deviations are between 1 and 4% for RTP.     

Enhanced Room-Temperature Phosphorescence through Intermolecular Halogen/Hydrogen Bonding

Room-temperature phosphorescence (RTP) materials with high efficiency have attracted much attention because they have unique characteristics that cannot be realized in conventional fluorescent materials. Unfortunately, efficient RTP in metal-free organic materials is very rare and it has traditionally been considered as the feature to divide purely organic compounds from organometallic and inorganic compounds. There has been increasing research interest in the design and preparation of metal-free organic RTP materials in recent years. It has been reported that intermolecular interactions make a big difference to the photophysical behavior of organic molecules. In this regard, herein, the parameters that affect RTP efficiency are discussed, and a brief review of recent intermolecular halogen-/hydrogen-bonding strategies for efficient RTP in metal-free organic materials are provided. The opportunities and challenges are finally elaborated in the hope of guiding promising directions for the design and application of RTP materials.     

Molecular Engineering for Metal‐Free Amorphous Materials with Room‐Temperature Phosphorescence

Materials displaying room‐temperature phosphorescence (RTP) have been attracting wide attention in recent years due to their distinctive characteristics including long emissive lifetime and large Stokes shift, and their various applications. Most synthesized RTP materials are metal complexes that display enhanced intersystem crossing and crystallization is a common way to restrict nonradiative transition. Amorphous metal‐free RTP materials, which do not rely on expensive and toxic metals and can be prepared in a straightforward fashion, have become an important branch of the field. This Minireview summarizes recent progress in amorphous RTP materials according to the approaches used to immobilize phosphors: host–guest interactions, molecule doping, copolymers, and small‐molecule self‐assembly. Some existing challenges and insightful perspectives are given at the end of the Minireview, which should benefit the future design and development of amorphous metal‐free RTP materials.     

胆酸盐簇集体刚性化微环境的灵敏指示——室温燐光探针法

胆酸盐是一类生物表面活性剂 ,一般含有羟基取代的类固醇骨架 ,并有一带负电的尾链 ,较为常见的胆酸盐有胆酸钠、脱氧胆酸钠、牛磺胆酸钠及牛磺脱氧胆酸钠等 .其分子结构见表 1及图 1所示 .Fig.1　Molecular structure of cholate surfactant胆酸盐是两亲分子 ,具有疏水性凸面和亲水性的凹面 ,在溶液中胆酸盐单体背靠背通过疏水 -亲脂作用力形成一个疏水内芯 ,亲水面朝向溶剂的簇集体 ,并增溶疏水性的小分子于簇集体内芯 ,使之处于一个疏水而高度保护的微环境中 .另外 ,胆酸盐单体之间通过疏水 -亲脂相互作用 ,可形成螺旋形簇集体 .由于具…     

离子交换树脂增稳的室温磷光特性及分析应用研究

本文研究了7-碘-8-羟基喹啉-5-磺酸及8-羟基喹啉-5- 磺酸同金属离子形成的配合物在水溶液中被阴离子交换树脂吸附后所表现出来的室温磷光特性. 制作了测定Al^3^+,Ga^3^+,In^3^+,Zr^4^+和Hf^4^+等金属离子的室温磷光传感器.实验结果表明:离子交换树脂增稳的室温磷光对湿气不敏感,选择性高, 可用于发展一类新型的金属离子传感器     

Spectroscopy behavior of 6-Mercaptopurine, Azathiopurine, and 8-Azaguanine

A comparative study, luminescence behavior of 6-Mercaptopurine (6-MP), Azathiopurine (BAN), and 8-Azaguanine (8-Azan) have been investigated including the low temperature phosphorescence, the low temperature fluorescence, the room temperature phosphorescence (RTP) and the room temperature fluorescence (RTF). The effect of pH on the luminescence intensity is discussed. Analytical characteristics of RTF and RTP of 6-MP, BAN, and 8-Azan have been studied. The lifetime of phosphorescence and the polarity of RTF and RTP have been examined.     

Sorption of methylxanthines by different sorbents

Sorption of caffeine, theophylline, theobromine, diprophylline, and pentoxyphylline on different sorbents (supercross-linked polystyrene, surface-modified copolymer of styrene and divinylbenzene Strata-X, and carbon nanomaterials Taunit and Diasorb-100-C₁₆T) was studied in a static mode in an effort to find new sorbents suitable for sorption isolation and concentration of methylxanthines. The peculiarities of sorption of methylxanthines were explained in relation to the solution acidity, the nature of the sorbates and their concentration, the nature of the solvent, and the structural characteristics of the sorbents.     

两种水溶性钯卟啉磷光探针的在位合成及其发光光谱特性研究

本文探索了合成水溶性钯卟啉(Pd—TAPP和Pd—TSPP)的最佳实验条件,通过紫外可见光谱、荧光光谱和室温磷光光谱研究了合成情况,并考察了其在不同有序介质中的室温磷光特性。     

Enantioselective detection of chiral phosphorescent analytes in cyclodextrin complexes

Inclusion complexes between camphorquinone (CQ) and cyclodextrins (CDs) in deoxygenated aqueous solutions are shown to exhibit relatively strong room temperature phosphorescence (RTP). Among the various CDs tested, α-CD showed the strongest RTP signals. Interestingly, these signals differed significantly for the two enantiomers of CQ; the phosphorescence lifetime of (+)-CQ was about four times longer than that of (−)-CQ, being 352 ± 16 and 89 ± 6 μs, respectively. This enantiomeric selectivity is attributed to a difference in dissociation rates (competing with the radiative emission process) for the diastereoisomeric inclusion complexes dealt with, which have a 2:1 stoichiometry (α-CD:CQ:α-CD). Time-resolved RTP detection using different delay times enables the determination of the two enantiomers in a mixture without involving a separation technique. The minimum detectable fraction of (+)-CQ in a 2 mM sample was 13%.     

Room temperature phosphorescence in the liquid state as a tool in analytical chemistry

A wide-ranging overview of room temperature phosphorescence in the liquid state (RTPL¹) is presented, with a focus on recent developments. RTPL techniques like micelle-stabilized (MS)-RTP, cyclodextrin-induced (CD)-RTP, and heavy atom-induced (HAI)-RTP are discussed. These techniques are mainly applied in the stand-alone format, but coupling with some separation techniques appears to be feasible. Applications of direct, sensitized and quenched phosphorescence are also discussed. As regards sensitized and quenched RTP, emphasis is on the coupling with liquid chromatography (LC) and capillary electrophoresis (CE), but stand-alone applications are also reported. Further, the application of RTPL in immunoassays and in RTP optosensing—the optical sensing of analytes based on RTP—is reviewed. Next to the application of RTPL in quantitative analysis, its use for the structural probing of protein conformations and for time-resolved microscopy of labelled biomolecules is discussed. Finally, an overview is presented of the various analytical techniques which are based on the closely related phenomenon of long-lived lanthanide luminescence. The paper closes with a short evaluation of the state-of-the-art in RTP and a discussion on future perspectives.     

Modified micellar electrokinetic chromatography in the analysis of catechins and xanthines in chocolate

Modified micellar electrokinetic chromatography (MEKC) analysis of monomeric flavanols (catechin and epicatechin) and methylxanthines (caffeine and theobromine) in chocolate and cocoa was performed by using sodium dodecyl sulfate (SDS) as a principal component of the running buffer. Because of the reported poor stability of catechins in alkaline solutions, acidic conditions (pH 2.5) were chosen and consequently the electroosmotic flow (EOF) was significantly suppressed; this resulted in a fast anodic migration of the analytes partitioned into the SDS micelles. Under these conditions, variations of either pH value in acidic range or SDS concentration, showed to be not suitable to modulate the selectivity. To overcome this limit, use of additives to the SDS-based running buffer was successfully applied and three different systems were optimized for the separation of (+)-catechin, (-)-epicatechin, caffeine, and theobromine in chocolate and cocoa powder samples. In particular, two mixed micelle systems were applied; the first consisted of a mixture of SDS and 3-[(3-cholamidopropyl)dimethylammonio]-1-propansulfonate (CHAPS) with a composition of 90 mM and 10 mM, respectively; the second was SDS and taurodeoxycholic acid sodium salt (TDC) with a composition of 70 mM and 30 mM, respectively. A further MEKC approach was developed by addition of 10 mM hydroxypropyl-beta-cyclodextrin (HP-beta-CD) to the SDS solution (90 mM); it provided a useful cyclodextrin(CD)-modified MEKC. By applying the optimized conditions, different separation profiles of the flavanols and methylxanthines were obtained showing interesting potential of these combined systems; their integrated application showed to be useful for the identification of the low level of (+)-catechin in certain real samples. The CD-MEKC approach was validated and applied to the determination of catechins and methylxanthines in aqueous extracts from four different commercial chocolate types (black and milk) and two cocoa powders.     

Room temperature phosphorescence decay of metal chelates in micellar media

The characteristics of the decay of the triplet state of metal chelates have been investigated in micellar media using room temperature phosphorescence (RTP) measurements of the Al-ferron (7-iodo-8-hydroxyquinoline-5-sulfonic acid) complex in cetyltrimethylammonium bromide (CTAB) micelles. Applications of such decay measurements include discrimination between metal complex species and evaluation of the stoichiometry of phosphorescent metal chelates. A thorough study of the effect of foreign ions (interferences) on the photochemical characteristics of RTP of the aluminum complex leads to a tentative classification of foreign cations. Results are compared with those for the Nb(V)-ferron phosphorescent complex in CTAB micelles and possible reaction mechanisms in the presence of micellar media are outlined in an effort to contribute to basic knowledge of micelle stabilized RTP of such inorganic ions.     

Persistent organic room temperature phosphorescence: what is the role of molecular dimers?

Molecular dimers have been frequently found to play an important role in room temperature phosphorescence (RTP), but its inherent working mechanism has remained unclear. Herein a series of unique characteristics, including singlet excimer emission and thermally activated delayed fluorescence, were successfully integrated into a new RTP luminogen of CS-2COOCH₃ to clearly reveal the excited-state process of RTP and the special role of molecular dimers in persistent RTP emission.

The first purely organic room temperature phosphorescence (RTP) luminogen, with singlet excimer emission and thermally activated delayed fluorescence (TADF) effect, was successfully developed.