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101.
Sambasivarao Kotha Kalyaneswar Mandal Ashoke Chandra Deb Shaibal Banerjee 《Tetrahedron letters》2004,45(52):9603-9605
A fast, efficient and environmentally benign solvent-free procedure has been developed for microwave-assisted Claisen rearrangement on a silica gel support. Various bis-allyl ketones were prepared using this protocol. 相似文献
102.
Sengupta Arijit Deb Ashish Kumar Singha Gupta Nishesh Kumar Kumar Parveen Dasgupta Kinshuk Ali Sk. Musharaf 《Journal of Radioanalytical and Nuclear Chemistry》2018,315(2):331-340
Journal of Radioanalytical and Nuclear Chemistry - Herein, sorption of pentavalent neptunium from aqueous acidic solution was carried out onto 1st and 2nd generation of poly(amidoamine) dendrimer... 相似文献
103.
Achiral four-ring unsymmetrically substituted toluene-derived liquid crystals have been designed and synthesised by known and straightforward methods. All these compounds exhibit nematic phase over wide temperatures. 相似文献
104.
M. K. Deb C. Agarwal K. S. Patel R. K. Mishra 《International journal of environmental analytical chemistry》2013,93(4):417-419
Abstract A simple and rapid method for the spectrophotometric determination of traces of total arsenic present in industrial waste waters is described. It is based on the reaction of As(III) with I? in 5 –6 M HCl, and extraction of the iodo-arsenite complex formed into chloroform with amidines. The molar absorptivity of AsI4 ? with 11 different amidines is in the range (3.9 –7.9) × 103 lmol?1 cm?1 at λmax = 380 –395 nm; the simplest compound, N,N′-diphenylbenzamidine (DPBA) has been chosen for further studies. The limit of detection with DPBA is 0.1 μg As/ml. The method is highly selective with almost no interference from all anions and cations tested. 相似文献
105.
Soluble phenol formaldehyde resin containing hydroxymethyl groups has been used to modify sulfonated poly(ether ether ketone) (SPEEK). Modification has been carried out with films containing both the polymers and using dimethyl formamide (DMF) as casting solvent at various temperatures under reduced pressure. Associated solvent and the hydrogen‐bonded by‐product dimethyl amine (DMA) were removed through mild alkali–acid–water treatment. Cured and treated films show good and consistent mechanical properties, water uptake (22–25%), ion‐exchange capacity (1.1–1.5 meq/g) and proton conductivity (125–150 mS/cm) at 30°C and hold promise for application in fuel cells, as indicated by a polarization study in a fuel cell test station. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
106.
Vanadyl acetylacetonate,VO(acac)2,has been found to be very effective catalyst for synthesis of a variety of benzimidazoles under solvent-free condition.The methodology involves the exposure of a mixture of o-phenylenediamine and a selected aromatic carboxylic acid/aldehyde to microwave radiation without the use of any solvent or supporting agents.The benzimidazoles were obtained in quick time with high yields. 相似文献
107.
Complexes of Calf thymus DNA with Cu2+ ions have been studied using ultraviolet (UV) absorption spectroscopy to probe the binding and melting behavior of DNA in the complex at 25°C, causing a melting of DNA as effectively as heating to 100°C. This strengthens the concept of Cu2+ binding to the DNA bases as recently demonstrated by Richard et al.1 相似文献
108.
Harshita Sharma Anushree Saha Arun Kumar Mishra Manish Kumar Rai Manas Kanti Deb 《印度化学会志》2022,99(7):100483
A new sensitive spectrophotometric method for the determination of glyphosate herbicide in environmental and agricultural samples is developed. The reaction is based on diazotization followed by coupling of glyphosate with p-dimethyl amino benzaldehyde. The resulted complex absorption spectra was observed at λmax = 420 nm. The effects of other metal ions and pesticides were also tested for selective determination of glyphosate. The analytical parameters were optimized and have been successfully applied for determination of glyphosate in various environmental samples such as soil, water and vegetables. This method has a lower limit detection of 6 μg of glyphosate. Beer's law is obeyed over the concentration range of 6.0 μg–24.0 μg glyphosate in 25 mL of the final solution at 420 nm. The standard deviation and relative standard deviation calculated are 0.0055 and 1.023, respectively. The molar absorptivity of the colored system is 1.91 × 1010 L mol?1cm?1 and Sandell's sensitivity is found 0.408 × 10?5 μg cm?2. The proposed method is simple, sensitive, highly reproducible and time saving as compare to those complicated time consuming methods. 相似文献
109.
Dr. Domenik Schleier Marius Gerlach Dr. Deb Pratim Mukhopadhyay Emil Karaev Dorothee Schaffner Dr. Patrick Hemberger Prof. Ingo Fischer 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(42):e202201378
We have investigated the photoionization of ammonia borane (AB) and determined adiabatic ionization energy to be 9.26±0.03 eV for the X+ 2E←X 1A1 transition. Although the threshold photoelectron spectrum appears at first glance to be similar to the one of the isosteric ethane, the electronic situation differs markedly, due to different orbital energies. In addition, an appearance energy AE0K(NH3BH3, NH3BH2+)= 10.00±0.03 eV has been determined, corresponding to the loss of a hydrogen atom at the BH3-site. From the data, a 0 K bond dissociation energy for the B−H bond in the cation of 71.5±3 kJ mol−1 was derived, whereas the one in the neutral compound has been estimated to be 419±10 kJ mol−1. 相似文献
110.
We consider a system of Brownian particles confined in a two-dimensional bilobal enclosure. Varying cross-section of the confinement results in an effective entropic potential in reduced dimension. We show that the system may undergo an entropic noise-induced transition when the shape of the stationary probability density changes qualitatively from bimodal to trimodal type under the influence of a multiplicative noise. 相似文献