A new efficient chemosensor 1 was prepared, for the detection of Fe3+ in solutions as a colorimetric and fluorescent sensor. The visual and fluorescent behaviors of the receptor toward various metal ions were also explored. The receptor shows exclusive response toward Fe3+ ions and also distinguishes Fe3+ from other cations by color change and fluorescence enhancement in hydroalcoholic solution (MeOH/H2O = 9/1, v/v). Thus, the receptor can be used as a colorometric and fluorescent sensor for the determination of Fe3+ ion. The fluorescence microscopy experiments showed that the chemosensor is efficient for detection of Fe3+ in vitro, developing a good image of the biological organelles.
Research on Chemical Intermediates - A dry rind of Aegle marmelos (bael) fruit ash as a synergetic alternative material to an expensive, toxic and corrosive catalysts for the synthesis of... 相似文献
Diversely functionalized nitrogen-containing heteroaromatic building blocks, fine chemicals and active pharmaceutical or agrochemical ingredients are conveniently prepared via CN bond formation as the key step. Since beginning of the last decade, there has been a flurry of intense research in forging CN bonds using iron catalysts due to their low cost, high natural abundance and non-toxic nature. The present review offers an overview of CN bond forming reactions involving aryl, allyl, propargyl and unactivated alkyl electrophilic substrates with nitrogen nucleophiles via the regular cross coupling reactions catalyzed by iron. In the miscellaneous section, a set of novel transformations facilitated by iron are included as well. 相似文献
An asymmetric domino Michael-hydroalkoxylation reaction of trans-α-alkynyl-nitroolefins with N-arylpyrazolinones has been accomplished using a chiral bifunctional squaramide catalyst. Under the organocatalytic method, a broad range of tetrahydropyrano[2,3-c]pyrazoles with an exocyclic alkene at the C-6 position were prepared in high yields and excellent stereoselectivities. The presence of an exocyclic double bond and nitro group in the pyranopyrazoles provide a wide scope for further structural transformations. 相似文献
A simple, miniaturized microplate chemiluminescence assay for determination of methyl parathion (MP) was developed in 384-microwell
plates. Zirconia (ZrO2) was added in microwell for adsorption of acetylcholinesterase (AChE). The developed assay is based on inhibition of AChE
by MP. A good dynamic range 0.008–1,000 ng/mL was obtained for MP with limit of detection 0.008 ng/mL. Intrabatch and interbatch
reproducibility for miniaturized assay was obtained with % RSD up to 3.07 and 5.66, respectively. In 384 well plate formats,
70 samples were simultaneously analyzed within 20 min with assay volume of 41.5 μL. The application of developed assay was
extended for MP remediation. Column containing ZrO2 was utilized for remediation where MP was selectively adsorbed. Under optimized condition, adsorption of MP on ZrO2 was found to be 98–99% with 2-h contact time in real water samples. Adsorption of MP on ZrO2 column followed by quantification using developed bioassay provides a novel approach to monitor remediation. The applicability
of assay was successfully extended for determination of MP in water samples after removal through ZrO2. 相似文献
Among known pesticide groups, organophosphates (OPs) have grasped attention due to their hazardous nature and their applications as pesticides and chemical weapons. This work presents the development of cost-effective column based biosensor for detoxification of OPs in water and milk. Enzyme phosphotriesterase (PTE) was immobilized on an activated Sepharose 4B via covalent coupling using an Omnifit glass column. Three different OPs, ethyl paraoxon (EPOx), malaoxon (MAO) and chlorpyriphos-oxon (CPO) were spiked in water and milk to test the detoxification of OPs. Mixtures of these pesticides were also tested to check the cumulative detoxification in the real samples. The efficiency of detoxification was evaluated using a highly sensitive acetylcholinesterase (AChE) B394 biosensor based flow system. The column conditions were optimized for the detoxification studied. The method was shown to be promising when we tested real milk samples spiked with OPs. Detoxification obtained in milk was up to 86% whereas in water, 100% detoxification was obtained. 相似文献
The formal synthesis of (?)-stemoamide was achieved starting from l-pyroglutamic acid. The key steps used are the allylation using BF3·OEt2, ring closing metathesis, allylic oxidation and a novel epimerization at C8. 相似文献
40PbO–(10 ? x)PbF2–50 SiO2:xWO3 (where x = 1 to 7 mol%) glasses are prepared in the glass forming region. Spectroscopic studies (UV–Vis absorption, ESR, IR) are carried out for these glasses. Interesting changes are observed in the spectroscopic parameters of these glasses when the concentration of WO3 is changing in the glass matrix. Two absorption bands are observed around at 830 and 620 nm. ESR signal are measured at room temperature for these glasses, the strength of the signal is increased and hyperfine splitting is resolved with increasing the concentration of WO3 in the glass matrix. IR transmission gives valuable information about the nature of bonds in the glass matrix. The physical parameters along with spectroscopic parameters are measured. 相似文献
Trifluoromethanesulfonic acid or triflate acid, chemical formula CF3SO3H, is regarded as one of the strongest acids and resembles Nafion® in structure. Erbium triflate, a lanthanum salt of triflate, is thermally stable. This paper reports data on the formation of membranes by the fixation of erbium triflate salts (ErTfO) into the Nafion structure. Five different loadings of ErTfO were used to fabricate ErTfO/Nafion composite membranes and these were characterized, extensively for possible use in direct alcohol fuel cells. The membranes were characterized using XRD, TGA, FTIR, and for mechanical strength, water uptake, ion exchange capacity, alcohol uptake, swelling, proton conductivity, alcohol permeability and oxygen stability. The ErTfO/Nafion composite membranes reduced alcohol permeability by 77–80%. The proton conductivity of 3% ErTfO/Nafion composite membranes was 38% higher than that of a pure cast Nafion membrane. The oxygen stability of the ErTfO/Nafion composite membranes was higher than pure cast Nafion. However, the mechanical strength of 7% and 9% ErTfO/Nafion was lower than that of pure cast Nafion. The composite membrane was chemically stable and has potential for use in direct alcohol fuel cells. 相似文献