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21.
The conventional condensation and refluxing process was employed to synthesize Ni(II) and Cu(II) complexes of Methylcarbamatethiosemicarbazone ligand. Reactions were carried out at the pH of 7. The molar ratio of the ligand and metal salt was 2:1. The structures of the synthesized metal complexes were suggested by different analytical techniques such as magnetic susceptibility, molar conductance, IR, EPR and UV spectroscopy. Experimental studies confirmed the octahedral geometry for all the complexes. The geometry of the ligand and complexes were also confirmed by theoretical studies. The complexes were investigated for biological action against pathogenic fungi (C. krusei, C. albican) and bacteria (S. aureus, E. coli). The antimicrobial results confirmed superior inhibition potential of the metal complexes as compared with the parent ligand. The enhanced antimicrobial activities might be due to the chelation. Molecular-docking assays confirmed the strong interaction of ligand with target antimicrobial protein DNA gyrase-B. 相似文献
22.
Here, we have reported a novel approach towards dual-nano assisted synthesis of disulfides from coupling of alkyl/aryl halides and sulfur nanoparticles. The indium oxide nanoparticles as catalyst expedite the conversion and sulfur nanoparticle notably enhances the miscibility, providing a faster, high yielding and cost-effective process in ethanol-water system. The method has synthetic advantages in terms of mild reaction framework, catalyst regeneration, and absence of any sulfide or polysulfide linkage as by-product leading to a column free synthesis. A variety of alkyl, aryl and heteroaryl symmetrical disulfides are obtained in good to excellent yields up to exceeding 98%. 相似文献
23.
Aggarwal Namita Rana Bharti Agrawal R. K. 《Multidimensional Systems and Signal Processing》2019,30(4):1839-1858
Multidimensional Systems and Signal Processing - The clinical diagnosis of Alzheimer’s disease (AD) is based on the tedious questionnaire and prolonged tests, which require involvement of the... 相似文献
24.
Ruso JM Deo N Somasundaran P 《Langmuir : the ACS journal of surfaces and colloids》2004,20(21):8988-8991
Interactions between sodium dodecyl sulfate and zein protein, a model system for the understanding of the effect of surfactants on skin, were investigated using a range of techniques involving UV-vis spectroscopy, TOC (total organic carbon analysis), electrophoresis, and static and dynamic light scattering. Zein protein was solubilized by SDS. The adsorption of SDS onto insoluble protein fraction caused the zeta potential of the complex to become more negative. From these values, we calculated the Gibbs energy of absorption, which decreases when the SDS concentration is raised. Finally the structure of the complex, based on the analysis by static and dynamic light scattering, is proposed to be rod like. 相似文献
25.
Deo P Deo N Somasundaran P Moscatelli A Jockusch S Turro NJ Ananthapadmanabhan KP Ottaviani MF 《Langmuir : the ACS journal of surfaces and colloids》2007,23(11):5906-5913
The interaction of a hydrophobically modified anionic polymer (PMAOVE) with a cationic surfactant (DTAB) was studied using a multi-technique approach: turbidity, surface tension, and viscosity measurements, as well as EPR (5-doxyl stearic acid) and fluorescence (pyrene) probe techniques were used. In the investigated pH range (4-10), the cationic surfactant headgroups interact with the anionic carboxylic groups of the polymer backbone. In addition, nonpolar interactions of the surfactant chains with the n-octyl chains of PMAOVE stabilize the PMAOVE-DTAB complexes. Charge neutralization of the anionic polymer by the cationic surfactant leads to precipitation of the PMAOVE-DTAB complex at a certain DTAB concentration range. Further addition of DTAB causes a charge reversal of the complex and, subsequently, resolubilization of the precipitate. At an acidic pH (pH = 4), a second precipitation was observed, which is probably caused by conformational changes in the PMAOVE-DTAB complex. This second precipitate can be resolubilized by further addition of surfactant. At a neutral and basic pH, this second precipitation is absent. EPR analysis indicates that the surfactants form an ordered structure at the extended polymer chain at a neutral and basic pH, whereas at an acidic pH, a less ordered surfactant layer is formed on the coiled polymer with more hydrophobic microdomains. 相似文献
26.
Bibhuti Parida Jitendra Sahoo Namita Shadangi P. Nayak 《Indian Journal of Physics》2010,84(10):1333-1339
Here we have considered the electron-phonon interaction in the Periodic Anderson Model (PAM) to describe the temperature dependence
of resistivity in some heavy fermion (HF) systems. Since the resistivity is related to the imaginary part of the electron
self energy, the expression of the same is evaluated from electron Green function by the double time temperature dependant
Green function technique of the Zubarev type. In order to understand the effect of electron-phonon interaction in these systems,
we couple the phonons to both the f-electrons as well as to the electrons of the hybridization band of both conduction and f-electrons. The influence of various model parameters, namely, the position of 4f level E
0, the electron-phonon coupling strengths f
1(q) and f
2(q), the effecting coupling strength g = N(0)γ
02/ω
0 have been studied on the temperature dependence of resistivity in HF systems. The numerical analysis is performed for q = 0 and for finite temperature in the static limit. The analysis of the results gives satisfactorily in comparison to the
experimental observations. 相似文献
27.
Satish P. Jain Namita D. Desai Sejal P. Shah P. S. Pirthipal Singh Purnima D. Amin 《Chromatographia》2009,69(11-12):1489-1491
The present research work discusses the development of a stability indicating reversed phase LC method for determination of ciprofloxacin hydrochloride as a bulk drug and from formulations. The mobile phase selected was water-acetonitrile-triethylamine 75:25:0.1 (v/v/v) adjusted to pH 4.0 with o-phosphoric acid. The calibration curve of the drug was linear in the range 0.25–15 μg mL?1. The method was accurate and precise with limits of detection and quantitation of 8.01 and 26.7 ng, respectively. Mean percent recovery was 100.71%. The method was used for analysis of ciprofloxacin hydrochloride from pharmaceutical formulations in the presence of its degradation products and commonly used excipients. 相似文献
28.
Namita Roy Choudhury 《Journal of Sol-Gel Science and Technology》2004,31(1-3):37-45
Novel dendrimer-titania hybrids were prepared in this work from hydroxy and amine terminated polyamidoamine dendrimer (PAMAM generation 4) and titanium alkoxide by an in-situ sol-gel process in presence of a ligand. Dendritic polymers are chosen because of their unique architectural features. Such dendrimer nanocomposite (DNC) can then be used for optical, catalytic, biomedical applications. The hybrid material formed in situ is found to be transparent, brittle and yellow in colour. The hybrids show higher thermal stability than their organic precursors. This is due to enhanced interaction of the inorganic material with the dendrimer through hydrogen bonding as evidenced by PA-FTIR. XPS studies show predominantly the existence of tetravalent titanium due to titania formation. 相似文献
29.
Archana Chaudhary Namita Sharma Veena Dhayal Arpita Saxena Meena Nagar Rakesh Bohra 《应用有机金属化学》2011,25(3):198-206
Some bis(cyclopentadienyl)titanium(IV) complexes of the type [Cp2TiCl2?n{L}n] {where, n = 1 or 2; L = ONC(R)Ar; R = H or CH3 and Ar = C5H4N‐2, C4H3O‐2 or C4H3S‐2} have been synthesized by the metathetical reactions of Cp2TiCl2 with the sodium salt of internally functionalized oximes in 1:1 and 1:2 stoichiometry in anhydrous THF. All these red to brown colored solid derivatives have been characterized by elemental analyses, FT‐IR and NMR (1H and 13C{1H}) spectral studies. The FAB mass spectra of some representative derivatives indicate their monomeric nature. Oximato ligands in all the complexes appear to bind the titanium via N and O in a dihapto ( ‐N, O) manner in the solid state. Thermogravimetric curves of [Cp2TiCl{ONC(CH3)C5H4N‐2}] and [Cp2Ti{ONC(CH3)C5H4N‐2}2] suggest the formation of hybrid materials CpTiO(Cl) and Cp2TiO, respectively, as the final products at 900 °C under nitrogen atmosphere. Sol–gel transformations of Cp2TiCl2, [Cp2TiCl{ONC(CH3)C5H4N‐2}] and [Cp2Ti{ONC(CH3)C5H4N‐2}2] yielded titania a–c, respectively, at low sintering temperature (600 °C). The powder XRD patterns, IR as well as Raman spectra of all these oxides indicate the formation of nano‐sized anatase phase. The SEM images of titania a–c indicate agglomers like surface morphologies. The absorption spectra of a–c exhibit an energy band gap in the range of 3.47–3.71 eV. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
30.
Probes based on anthra[1,2-d]imidazole-6,11-dione were designed and synthesized for selective ion sensing. Each probe acted as strong colorimetric sensors for fluoride and cyanide ions and exhibited intramolecular charge transfer (ICT) band, which showed significant red-shifts after addition of either the F(-) or CN(-) ion. One of the probes (2) showed selective colorimetric sensing for both cyanide and fluoride ions. In organic medium, 2 showed selective color change with fluoride and cyanide, whereas in aqueous organic medium it showed a ratiometric response selectively for cyanide ion. 相似文献