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71.
Pradhan Rabindranath Bhattacharyya Ramgopal Kumar Sanjay Banerjee Dilip 《Transition Metal Chemistry》1999,24(4):431-435
Tetrathiomolybdate reacts with iron (II) in the presence of bidentate ligands to form neutral binuclear complexes [Fe(N–N)2MoS4] [N–N=2-2bipyridine(bipy) and 1,10-phenanthroline(phen)] showing intermediate spin character for FeII. The spin state of the complexes has been examined by variable temperature magnetic moment (VTM) measurements and by variable temperature Mössbauer spectroscopy. The Mössbauer spectra indicate the presence of two iron sites: one of intermediate spin and the other of low spin at room temperature. The low spin site predominates over the intermediate spin as the temperature is lowered. The structural features of the complexes are supported by i.r., Raman, electronic and FAB mass spectra and by X-ray powder diffraction data. Substitution of one bipy/phen ligand in [Fe(N–N)3]2+ by MS4
2– ligands does not impart any major effect towards the size of the redox potentials of the tris-bipy/phen complexes, although the reversible nature of their cyclic voltammetric response is affected. 相似文献
72.
Anand G. Patil Dilip Reddy Russell D'Souza Anagha Damre 《Biomedical chromatography : BMC》2010,24(6):620-625
A simple, sensitive and specific reverse‐phase high‐performance liquid chromatographic (RP‐HPLC) method with fluorescence detection was developed for quantitation of quinidine from HBSS buffer. The method was applicable in the bi‐directional transport assay for evaluation of the inhibitory effect of test compounds on P‐glycoprotein‐mediated quinidine transport; quinidine was used as a probe P‐glycoprotein substrate. The calibration curve was linear (correlation coefficient ≥99) in the range 0.30–100.00 nm. The method was validated and is specific and sensitive with limit of quantitation of 300 pm for quinidine. The method was found to be accurate and precise in the working calibration range. Stability studies were carried out at different storage conditions where the analyte was found to be stable. The applicability and reliability of the analytical method was evaluated by successful demonstration of efflux ratio (PappB → A/PappA → B) in the Caco‐2 cell monolayer efflux assay. The efflux ratio for quinidine (100 nm) alone was 10.8, which reduced to less than 2 in the presence of the classical P‐gp inhibitors verapamil and ketoconazole (100 μm each). Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
73.
A novel vanadium polyoxometalate [(C6H5CH2)(CH3)3N]3[H3V10O28]3H2O works as a useful oxidant for selective and rapid oxidation of benzylic alcohols to the corresponding carbonyl compounds in the presence of PTSA under solvent-free, room temperature in excellent yield. 相似文献
74.
Rahul R. Kolhapurkar Preeti K. Patil Dilip H. Dagade Kesharsingh J. Patil 《Journal of solution chemistry》2006,35(10):1357-1376
Experimental measurements of the speed of sound, density and osmotic vapour pressure are reported for binary 18-Crown-6 (18C6) + CH3OH, KBr + CH3OH and ternary KBr + 18C6 + CH3OH solutions at 298.15 K. The density and compressibility data were processed to obtain the apparent molar volume (ø V ) and apparent molar isentropic compressibility ( $\phi _{K_S } Experimental measurements of the speed of sound, density and osmotic vapour pressure are reported for binary 18-Crown-6 (18C6) + CH3OH, KBr + CH3OH and ternary KBr + 18C6 + CH3OH solutions at 298.15 K. The density and compressibility data were processed to obtain the apparent molar volume (?
V
) and apparent molar isentropic compressibility () of the solutes in methanol. Expansivity data were obtained for the 18C6 + CH3OH system from density data at different temperatures and were used for calculation of the isothermal compressibility values at 298.15 K. The isothermal compressibility and expansivity data are further used to obtain the apparent molar isothermal compressibility () and apparent molar expansivity (?
E
) of 18C6 in methanolic solutions and as well as the energy-volume coefficient parameter (∂ U/∂ V)
T
in methanol solutions. The volume and compressibility changes due to complexation of KBr with 18C6 are obtained at infinite dilution for ?
V
and ?
K
. The results are compared with the similar data obtained by us previously for aqueous and CCl4 solutions. The osmotic coefficient data were used to calculate activities and activity coefficients of each component at 298.15 K as a function of the concentration of binary and ternary methanolic solutions containing KBr and 18C6. The activity and activity coefficient data are used to evaluate the pair and triplet interaction parameters by making appropriate use of the McMillan-Meyer theory of solutions. The calculation of the thermodynamic equilibrium constant (K) is made using the pair interaction parameter, g
NE
(non-electrolyte – electrolyte pair interaction), for the complexation equilibria. The nature of interactions present in the CH3OH solutions is discussed. 相似文献
75.
76.
77.
The intramolecular aminomercuration reaction of sugar-derived beta-hydroxy-gamma-alkenylamines 8a-c undergoes 5-endo-trig cyclization in high yield. The sugar-substituted pyrrolidines thus obtained were elaborated to the synthesis of polyhydroxylated indolizidine alkaloids, namely, castanospermine 1a, 1-epi-castanospermine 1b, and 8a-epi-castanospermine 1c, having promising glycosidase inhibitory activities. 相似文献
78.
Ramgir NS Late DJ Bhise AB More MA Mulla IS Joag DS Vijayamohanan K 《The journal of physical chemistry. B》2006,110(37):18236-18242
A simple method of vapor deposition for the shape selective synthesis of ZnO structures, namely, multipods, submicron wires, and spheres, has been successfully demonstrated. A plausible growth mechanism based on the studies of scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) is proposed. Our studies suggest that the growth of a multipod structure is governed by the screw dislocation propagation while the vapor-liquid-solid (VLS) mechanism is responsible for the formation of submicron wires and spheres. Moreover, the flow rate of the carrier gas plays a crucial role in governing the morphology. Further, these structures exhibit an enhanced field emission behavior. The nonlinearity in the Fowler-Nordheim (F-N) plot, a characteristic feature of electron emission from semiconductors, is explained by considering the contributions from both the conduction and the valence bands of ZnO. 相似文献
79.
Stereoselective synthesis of 2'-C-methyl-cyclopropyl-fused carbanucleosides was accomplished via stereoselective cyclopropanation, regioselective cleavage of the isopropylidene group, stereoselective Grignard reaction, and cyclic sulfate chemistry. [reaction: see text] 相似文献
80.
A significant rate enhancement was observed in the preparation of allyl and allenyl-C-glycosides from glycosyl acetate or methyl O-glycoside precursors when ultrasound irradiation was employed as an energy source. The C-glycosides were obtained in 77-96% yields in <20 min using TMSOTf as promoter. These results show that sonication provides rapid and efficient access to useful C-glycoside-based building blocks. 相似文献