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81.
Vikas?D.?GhuleEmail author Dharavath?Srinivas S.?Radhakrishnan Pandurang?M.?Jadhav Surya?P.?Tewari 《Structural chemistry》2012,23(3):749-754
Density functional theory has been used to investigate geometries, heats of formation (HOFs), C-NO2 bond dissociation energies (BDEs), and relative energetic properties of nitro derivatives of azole substituted furan. HOFs for a series of molecules were calculated by using density functional theory (DFT) and Møller–Plesset (MP2) methods. The density is predicted using crystal packing calculations; all the designed compounds show density above 1.71 g/cm3. The calculated detonation velocities and detonation pressures indicate that the nitro group is very helpful for enhancing the detonation performance for the designed compounds. Thermal stabilities have been evaluated from the bond dissociation energies. Charge on the nitro group was used to assess the impact sensitivity in this study. According to the results of the calculations, tri- and tetra-nitro substituted derivatives reveal high performance with better thermal stability. 相似文献
82.
B. S. Mohite B. E. Mahadik A. S. Jadhav 《Journal of Radioanalytical and Nuclear Chemistry》2000,245(2):343-346
A simple column chromatographic method has been developed for the separation of thorium(IV) from associated elements using poly-(dibenzo-18-crown-6). The separations are carried out from picric acid medium. The adsorption of thorium(IV) was quantitative from 0.0005–0.05M picric acid. Amongst the various eluents tested, 2.0–8.0M HCl, HBr, 1.0–6.0M HClO4 and 5.0M acetic acid were found to be particularly efficient for the quantitative elution of thorium(IV). The capacity of poly-(dibenzo-18-crown-6) for thorium(IV) was found to be 1.29±0.01 mmol/g of crown polymer. Thorium(IV) was separated from a number of cations in binary mixtures in which most of the cations showed a very high tolerance limit. It was possible to separate thorium(IV) from a number of cations such as lanthanum(III), yttrium(III), uranium(VI), beryllium(II) and barium(II) in multicomponent mixtures. The method was extended to the determination of thorium in monazite sand. It is possible to separate and determine 5 ppm of thorium(IV) by this method. The method is very simple, rapid, selective and has good reproducibility (approximately ±2%). 相似文献
83.
An electrochromic system based on a self‐assembled dipeptide‐appended redox‐active quinquethiophene π‐gel is reported. The designed peptide‐quinquethiophene consists of a symmetric bolaamphiphile that has two segments: a redox‐active π‐conjugated quinquethiophene core for electrochromism, and peptide motif for the involvement of molecular self‐assembly. Investigations reveal that self‐assembly and electrochromic properties of the π‐gel are strongly dependent on the relative orientation of peptidic and quinquethiophene scaffolds in the self‐assembly system. The colors of the π‐gel film are very stable with fast and controlled switching speed at room temperature. 相似文献
84.
The cross-coupling reaction of triarylbismuths with acid chlorides using a catalytic amount of PdCl2/PPh3 afforded the corresponding ketones in high yields. The reactions of aromatic and aliphatic acid chlorides occurred with atom efficiency, as 3 equiv of acid chlorides coupled effectively with 1 equiv of triarylbismuths to yield 3 equiv of the corresponding diaryl and alkyl aryl ketones. 相似文献
85.
Isocratic reversed phase high performance liquid chromatographic (HPLC) method using RP C18 column was developed for simultaneous
determination of the curcuminoids. Mobile phase consisted of acetonitrile:0.1% trifluro-acetic acid (50:50) and flow rate
was 1.5 mL min−1 and elution was monitored at 420 nm. Validation in selected conditions showed that the chosen method is sensitive, selective,
precise and reproducible with linear response of detector for the simultaneous determination of curcumin (C), demethoxycurcumin
(DMC) and bis-demethoxycurcumin (BDMC). The limits of detection were 27.99, 31.91 and 21.81 ng mL−1 for C, DMC and BDMC, respectively. Limits of quantitation for C, DMC and BDMC, were 84.84, 96.72 and 66.10 ng mL−1, respectively. Linear range was form 100 to 600 ng mL−1. The mean ± SD percent recoveries of curcuminoids were 99.87 ± 0.34, 100.09 ± 0.48 and 100.10 ± 0.60% of C, DMC and BDMC,
respectively. Further, the method was used for quantitation of curcuminoids from turmeric rhizome. 相似文献
86.
L. U. Joshi U. C. Mishra K. G. Vohra S. G. Jadhav 《Journal of Radioanalytical and Nuclear Chemistry》1980,59(2):367-372
High activities of radium were observed in the spring waters of Tuwa in Panchamahal district of Gujarat state. These determinations
have led to further studies on geochemical behaviour of uranium in the surface sediments of this region. Labile uranium from
the surface of the sediment particles is leached with saturated solution of ammonium carbonate. Uranium is chemically separated
from the leachates by cellulose column chromatography. Unusually high activity ratios of234U/238U in the range of 2.3 to 2.77 were observed on the surface of the particles. The core of the particles exhibited a ratio of
1.00 indicating soluble234U fraction has migrated. 相似文献
87.
Benzeneacetaldehyde-4-hydroxy-α-oxo-aldoxime is proposed as a new sensitive and selective reagent for the spectrophotometric determination of cobalt. The reagent reacts with cobalt in the pH range 8.6–9.4 to form a yellow colored 1:3 chelate which is very well extracted in chloroform. Beer's law is obeyed in the concentration range 0.05–1.3 μg ml−1 cobalt. The molar absorptivity of the extracted species is 2.746×104 l mol−1 cm−1 at 390 nm. The proposed method is highly sensitive, selective, simple, rapid, accurate and has been satisfactorily applied for the determination of cobalt in synthetic mixtures, pharmaceutical samples, biological samples and alloys. 相似文献
88.
Pierce ME Harris GD Islam Q Radesca LA Storace L Waltermire RE Wat E Jadhav PK Emmett GC 《The Journal of organic chemistry》1996,61(2):444-450
DMP 323, a potent HIV-1 protease inhibitor, has been synthesized by an efficient stereoselective process, amenable to large scale preparations. The core C(2) symmetric diol was synthesized by a stereoselective pinacol coupling of CBZ protected D-phenylalanine. Judicious selection of protecting groups allowed cyclic urea formation under mild conditions, enhanced the ease of bis-alkylation, and led to intermediates which were easily purified without chromatography. Additionally, a one-pot, high yield process was developed to prepare the alkylating agent, 4-[(triphenylmethoxy)methyl]benzyl chloride from 1,4-benzenedimethanol. 相似文献
89.
N. D. Ghatge J. Y. Jadhav 《Journal of polymer science. Part A, Polymer chemistry》1983,21(7):1941-1950
Novel poly(ether urethanes) were synthesized by homo- and random copolymerization of the m- and p-hydroxyethoxy benzoyl azides. Polymerization proceeded by decomposition and rearrangement of the acid azide group to the isocyanate group, which immediately reacted intermolecularly with the hydroxyl group to produce polyurethanes. These polymers were characterized by infrared spectroscopy (IR), nuclear magnetic resonance spectroscopy (NMR), x-ray diffraction, scanning electron microscopy (SEM), viscosity, and solubility. The thermal stability of these polymers was also studied by TG and DTG (derivative TG). 相似文献
90.
A simple separation method has been developed for thorium(IV) using poly-(dibenzo-18-crown-6) and column chromatography. The separation was carried out from ascorbic acid medium. The adsorption of thorium(IV) was quantitative from 0.001-0.01M ascorbic acid. The elution of thorium(IV) was quantitative with 4.0-8.0M HCl, 3.0-6.0M HClO4, 4.0-8.0M H2SO4 and 1.0-8.0M HBr. The capacity of poly-(dibenzo-18-crown-6) for thorium(IV) was found to be 1.379±0.01 m.mol/g of crown polymer. Thorium(IV) was separated from a number of cations in binary as well as in multicomponent mixtures. The method was extended to the determination of thorium in monazite sand. It is possible to separate and determine 5 ppm of thorium(IV) by this method. The method is very simple, rapid, selective and has good reproducibility (approximately ±2%). 相似文献