Deep eutectic solvents (DESs), called a new generation of green solvents, have broad applied in synthesis of nanomaterials due to their remarkable physicochemical properties. In this work, we used a unique strategy (adding moderate water (10%) to DES) to effectively prepare nanomaterials. Flower-like AuPt alloy nanoparticles were successfully synthesized using one-step electrochemical reduction method at a low potential of −0.30 V (vs. Pt) and a low temperature of 30 °C. In this process, the DES acted as solvent and shape-directing agent. More importantly, we used the electrode modified with the as-prepared nanomaterials as the anode to the electrochemical oxidation synthesis. The glassy carbon electrode modified with the AuPt nanoflowers was directly employed to the electro-oxidation of xanthene (XT) to xanthone (XO) under a constant low potential of 0.80 V (vs. Ag/AgCl) and room temperature, with a high yield of XO. Moreover, the synthesis process was milder and more environment-friendly than conventional organic syntheses. This new strategy would have a promising application in electroorganic synthesis fields.

Research Pregress on Synthesis of Xanthene Dyes

Synthesis of Xanthene Derivatives Catalyzed by Modified Active Carbon Supported Ferric Chloride

The surface interactions between xanthene (XN) dyes, including rhodamine B, rhodamine 3B, rhodamine 19, rhodamine 6G, rhodamine 110, and rhodamine 123, and tungsten(VI) oxide (WO3) colloid particles were investigated. These XN dyes were strongly adsorbed as a monolayer onto the WO3 surface via the electrostatic interaction between their peripheral cationic amino substituents and negatively surface-charged WO3 colloid particles, and most of the ones adsorbed eventually formed stable π-stacked dimers. The geometry of dimers formed on the WO3 colloid surface is discussed on the basis of the molecular exciton theory framework. Cationic XN dyes formed the approximately ideal face-to-face H-dimers on the WO3 colloid surface, whereas zwitterionic ones had a higher tendency to form the oblique J-dimers. Additionally, we have experimentally demonstrated the possibility of pH-induced switching between H- and J-aggregation modes of the XN dye’s dimers formed on the WO3 colloid surface. The findings lead to a better understanding of organic dye’s adsorption/aggregation behaviors on the metal oxide surface.

芴酮与2-萘酚在硫酸和3-巯基丙酸的作用下反应得到化合物螺[二苯并[ a，j ]氧杂蒽-14，9’-芴]. 采用核磁共振、质谱、红外光谱和元素分析等对该化合物进行了表征，并通过X射线衍射法测得了其晶体结构，确定该化合物是通过二苯并[ a，j ]氧杂蒽中的含氧六元杂环和芴中的五元环共用一个碳原子形成一个螺环. 利用荧光光谱和热分析等手段对该化合物的性质进行了研究，结果表明其最大荧光发射峰为366 nm，熔点为297 ℃，热分解温度为329 ℃，具有较高的热稳定性.

Abstract

Synthesis and Application of a Novel Fluorescent Probe Based on Rhodamine B Thiohydrazide Derivatives for Determination of Hg(Ⅱ)

Chlorination of xanthenone by thionyl chloride gave an intermediate 9,9-dichloroxanthene.The obtained chlorinated product is free of further isolation and purification and can react with o-cresol or 2,6-dimethylphenol for the preparation of two xthanenebiphenols including 9,9-bis(4-hydroxy-3-methylphenyl) xanthene and 9,9-bis(4-hydroxy-3,5-dimethylphenyl) xanthene with corresponding yields of 81% and 80.5%.Their structures were characterized by elemental analysis,FTIR,1H NMR and 13C NMR spectra.The present method has advantages such as mild reaction conditions,convenient manipulation and good yield.

Quantum chemical investigation and statistical analysis of the relationship between corrosion inhibition efficiency and molecular structure of xanthene and its derivatives on mild steel in sulphuric acid

Adsorption behavior and corrosion inhibitive potential of xanthene on mild steel/sulphuric acid interface

Synthesis of C9-Functionalized Xanthenes and Acridines

Foram preparados novos exemplos de liquidos ionicos hidrofilicos e hidrofobicos, estaveis frente ao ar e a umidade, derivados de amonio bi-quaternario. Esses liquidos ionicos foram propostos para atuar como pigmentos biologicamente ativos, com caracteristicas fisico-quimicas unicas, como uma alternativa a alguns pigmentos convencionais anionicos derivados de xanteno, como eosina Y, fluoresceina e eritrosina. New examples of air- and moisture-stable, hydrophobic and hydrophilic bis-quaternary ammonium derived ionic liquids have been prepared. These ionic liquids have been proposed to act as biological active dyes with characteristic unique physicochemical properties, providing alternatives to some conventional anionic xanthene dyes such as eosine Y, fluorescein and erythrosine.

Experimental study of xanthene dyes as carcinogenic agents.

Objecflve To evaluate the performance of two rapid and low-cost metheds(MTT test,and rosazurin mierotitre assay)for the detection of resistance to first-line drugs in Mycobacterium tuberculosis.Methods sixty-four Myeobaeterium tuberculosis clinical isohtes were tested by the MTT test and the rosazuxin microtitre assay(REMA)respectively,and the results were compared with those obtained with the absolute concentration method on L(o)wenstein Jensen medium.Results The MTT test and the resazurin microtitre assay showed a good agreement compared with the absolute concentration method for all first-line drugs tested.The sensitibity,specificity and accuracy of the MTT test were 94.8%,96.0%,95.3%,for RFP;93.8%,93.8%,93.8% for INH;92.9%,96.O%,95.3% for EMB,90.6%,87.5%,89.1% for SM,respectively.The sensitivity,specificity and accuracy of the resazurin microtitre assay were 92.3%,96.0%,93.8%,for RFP;90.6%,90.6%,90.6% for INH;92.9%,94.0%,93.8% for EMB,87.5%,87.5%,87.5% for SM,respectively.The Kappa value of the MTT test and the absolute concentration method for the detection of resistance to RFP,INH,EMB,SM were 0.857,0.831,0.714,0.792.respeedvely;The Kappa value of the regazurin mierotitre assay and the absolute concentration method for the detection of resistance to RFP,INH,EMB,SM were 0.871,0.826,0.826,0.750,respectively.The Kappa value of the MTT test and the resazurin microtitre assay for the detection of resistance to RFP,INH,EMB,SM wefe 0.889,0.875.0.787,0.844,respectively.Conclusions Both MTT test and the resazurin microtitre assays are simple,rapid,low-cost and sensitive for rapid detection of resistance to first-line drugs.They could be promising methods for susceptibility assay of the first-line antituberculosis drugs in low-resource countries. Key words: Mycobacterium tuberculosis; Antitubercular agents; Microbial susceptibility tests; Tetrazolium salts; Oxazines; Xanthenes

Synthesis of 14-Substituted-14<i>H</i>-dibenzo[<i>a</i>,<i>j</i>]xanthenes Promoted by Amberlyst-15

A novel xanthene from Indigofera longeracemosa stem

The reaction of the morpholinal or anil of 5-nitrosalicylaldehyde with β-naphthol yielded (2-hydroxy-5-nitrophenyl)di[1-(2-hydroxynaphthyl)]methane. Condensation of the latter compound in boiling nitromethane gave 12-[1-(2-hydroxynaphthyl)]-10-nitro-12H-benzo[α]xanthene.

Abstract The uncatalyzed transfer hydrogenation of substituted α‐methylstyrenes with 9,10‐dihydroanthracene (DHA), xanthene (XAN), or 9,10‐dihydroacridine (DHAC) was studied mechanistically. The three hydrogen donors react at very similar rates and with similar activation parameters and with little discrimination between the various substituted styrenes. The kinetic isotope effects are also similar and the solvent effect is small. A hydrogen atom transfer mechanism (retrodisproportionation) is, therefore, preferred to a hydride transfer mechanism. This is supported by the very similar reactivity of the hydrogen transfer reaction of DHA and XAN with 9‐methylenefluorene. The product yields in all reactions investigated in this project were &gt;90%.

A number of electron donors, acceptors and diads containing xanthene dyes were sythesized. When the dyes were excited, the rate constants and the efficiencies of the intermolecular and intramolecular photo-induced electron transfer reactions were determined and calculated. It is found that the photo-induced electron transfer reactions occurred between xanthene dyes and many, including very weak donors or acceptors. The rate constants of intermolecular reactions were controlled by diffusion, and influenced by the reactant concentrations. The laser flash experiments showed that for low reactant concentrations, this kind of reactions took place mainly via the triplet excited state of the dyes. If different electric charges exist with dyes and donors/acceptors, there will be static quenching of the dyes' fluorescence. The intramolecular electron transfer reactions are independent of the solution concentrations, and they may directly proceed via the singlet excited state of the dyes effectively.

MNDO-calculated heats of formation and ionization potentials of 248 structures involving substituted toluenes, diphenylmethanes (DPMH), xanthenes (XAN), 9H,10H-acridines (ACR), 9H-10-N-methylacridines (N-MACR), benzenes, and the corresponding carbocations are reported