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81.
Rajesh G. Kalkhambkar G. Aridoss Geeta M. Kulkarni R. M. Bapset T. Y. Mudaraddi N. Premkumar Yeon Tae Jeong 《Monatshefte für Chemie / Chemical Monthly》2011,14(5):305-315
Abstract
A series of new ethers of quinolinone linked with different substituted coumarins and benzofurans were synthesized from 4-(bromomethyl)quinolinones. All newly synthesized compounds were screened for their in vitro antibacterial and antifungal activities. Most of the compounds with chloro substitution at the C-6 or C-7 position in quinolinone showed potent antibacterial and antifungal activities. In pharmacological evaluations, some of these chloroquinolinones also showed 70–77% inhibition of inflammation after 8 h, whereas the other compounds showed 51–55% inhibition. Most of the compounds showed potent analgesic activity compared to the standard and control. The structures of all newly synthesized compounds were characterized by elemental analysis, IR, 1H NMR, 13C NMR, and EI-MS. 相似文献82.
Geeta Kheter Paul S. S. Indi S. Ramakrishnan 《Journal of polymer science. Part A, Polymer chemistry》2004,42(20):5271-5283
Two novel two‐tail surfactants, dicetyldimethylammonium 4‐vinyl benzoate (DDVB) and dicetyldimethylammonium 3,5‐divinyl benzoate (DDDB), were synthesized by neutralizing the corresponding quaternary ammonium hydroxide with the appropriate benzoic acid. As expected, these surfactants formed both homo and mixed‐vesicles, which were readily polymerized with a suitable radical photo‐initiator. The polymerization process was followed by UV–vis spectroscopy and also reconfirmed by NMR and IR spectroscopy. Polymerization of vesicles prepared from DDVB, unlike the more commonly polymerized vesicles, in which the polymerizable group forms an integral part of the surfactant, leads to the formation of a linear polyelectrolyte chain that is only electrostatically bound to the lipid bilayer. On the other hand, polymerization of DDDB vesicles leads to the formation of a crosslinked shell (or net) that encases the vesicle bilayer. Such counterion crosslinked vesicles were shown to be resistant to destabilization both by lysis as well as in the presence of a fairly high volume fraction of an organic solvent, such as ethanol. However, although the simple polymerized (linearly) vesicles, formed from DDVB, exhibit enhanced stability toward lysis when compared to their unpolymerized counterparts, they are readily destabilized in the presence of ethanol, leading to precipitation. This sharp contrast in the behavior of linearly polymerized and crosslinked systems suggests that crosslinking is essential to arrest conformational reorganization of the polyelectrolyte chains induced by a change in the solvent medium, which in turn leads to precipitation. Such counterion crosslinked vesicular systems also have an added advantage; they may retain the fluidityof the lipid bilayer while at the same time possess enhanced stability. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 5271–5283, 2004 相似文献
83.
84.
The effect of substitution pattern on conjugation and packing has been investigated by synthesizing a series of tetrathiophenes with systematically varied alkyl thiophene substituents. 相似文献
85.
研究了在应力自由和刚性固定边界条件下,无能量耗散的均匀、各向同性微极热弹性无限板的轴对称自由振动波的传播,导出了相应的对称和斜对称模态波传播的闭合式特征方程和不同区域的特征方程.对短波的情况,应力自由热绝缘和等温板中对称和斜对称模态波传播的特征方程退化为Rayleigh表面波频率方程.根据导出的特征方程得到了热弹性、微极弹性和弹性板的结果.在对称和斜对称运动中计算了板的位移分量幅值、微转动幅值和温度分布,给出了对称和斜对称模式的频散曲线,并示出了位移分量和微转动幅值和温度分布的曲线.能够发现理论分析和数值结论是非常一致的. 相似文献
86.
Geeta Patkare Muhammed Shafeeq Dr. Arijit Sengupta Dr. Meera Keskar Dr. Rohan Phatak Prof. Shanmugaperumal Kannan 《欧洲无机化学杂志》2023,26(17):e202300140
Thermo physical properties of potassium, rubidium and cesium thorium phosphate compounds were investigated. All compounds were synthesized by conventional solid state method. Formation of orthorhombic AMThP3O10, tetragonal AM2Th(PO4)2 and monoclinic AMTh2(PO4)3; [AM=K, Rb and Cs] was confirmed using Powder X-ray diffraction (XRD) technique. Structural study of CsThP3O10 was carried out for the first time from Rietveld refinement of XRD data. Thermal stability of all compounds was established using Thermogravimetric analysis (TGA) technique. When heated at 1673 K for 30 h in air, all the compounds decompose to ThO2. High temperature X-ray diffraction (HT-XRD) data of the compounds, synthesized during present study, were collected in an inert atmosphere from ambient to 973 K and their thermal expansion coefficients were calculated. These compounds show positive thermal expansion up to 973 K. Molar heat capacities for all phosphates were measured between 300–863 K using Differential Scanning Calorimeter. Alkali metal thorium phosphates, AMThP3O10 and AMTh2(PO4)3, showed efficient uptake of uranyl ion from aqueous acidic medium predominantly following Langmuir isotherm and Webber Morris intra particle diffusion kinetics. 相似文献
87.
Rajesh G. Kalkhambkar G. Aridoss Geeta M. Kulkarni R. M. Bapset J. C. Kadakol N. Premkumar Yeon Tae Jeong 《Monatshefte für Chemie / Chemical Monthly》2012,21(9):1075-1086
Abstract
A series of new acrylic acid ethyl esters of quinolinones were synthesized from 4-(bromomethyl)quinolinones and screened for in vitro antimicrobial and in vivo analgesic and anti-inflammatory activities. Most of the compounds with chloro substitution at the C-6 or C-7 position in the quinolinone moiety and a methoxy group in the aryloxy moiety showed potent antibacterial and antifungal activities when compared with non-halogenated quinolinones and the quinolinones bearing a CH3 at the C-8 position. In a pharmacological evaluation, the halogen substitution at the C-6 or C-7 position in quinolinones was found to enhance both analgesic and anti-inflammatory activities of the molecule when compared with a simple unsubstituted (non-halogenated) quinolinone. The structures of all newly synthesized compounds were characterized by elemental analysis, IR, 1H NMR, 13C NMR, and FAB-MS. 相似文献88.
Prof. Dr. Tarlok S. Lobana Parminderjit Kaur Geeta Hundal Ray J. Butcher Chen W. Liu 《无机化学与普通化学杂志》2012,638(14):2340-2346
Reaction of 1, 9‐dihydro‐purine‐6‐thione (puSH2) in presence of aqueous sodium hydroxide with PdCl2(PPh3)2 suspended in ethanol formed [Pd(κ2‐N7,S‐puS)(PPh3)2] ( 1 ). Similarly, complexes [Pd(κ2‐N7,S‐puS)(κ2‐P, P‐L‐L)] ( 2 – 4 ) {L‐L = dppm (m = 1) ( 2 ), dppp (m = 3) ( 3 ), dppb (m = 4) ( 4 )} were prepared using precursors the [PdCl2(L‐L)] {L‐L = Ph2P–(CH2)m–PPh2}. Reaction of puSH2 suspended in benzene with platinic acid, H2PtCl6, in ethanol in the presence of triethylamine followed by the addition of PPh3 yielded the complex [Pt(κ2‐N7,S‐puS)(PPh3)2] ( 5 ). Complexes [Pt(κ2‐N7,S‐puS)(κ2‐P, P‐L‐L)] ( 6 – 8 ) {L‐L = dppm ( 6 ), dppp ( 7 ), dppb ( 8 )} were prepared similarly. The 1, 9‐dihydro‐purine‐6‐thione acts as N7,S‐chelating dianion in compounds 1 – 8 . The reaction of copper(I) chloride [or copper(I) bromide] in acetonitrile with puSH2 and the addition of PPh3 in methanol yielded the same product, [Cu(κ2‐N7,S‐puSH)(PPh3)2] ( 9 ), in which the halogen atoms are removed by uninegative N, S‐chelating puSH– anion. However, copper(I) iodide did not lose iodide and formed the tetrahedral complex, [CuI(κ1‐S‐puSH2)(PPh3)2] ( 10 ), in which the thio ligand is neutral. These complexes were characterized with the help of elemental analysis, NMR spectroscopy (1H, 31P), and single‐crystal X‐ray crystallography ( 3 , 7 , 8 , 9 , and 10 ). 相似文献
89.
Geeta A. Zalmi Vilas K. Gawade Dinesh N. Nadimetla Prof. Sheshanath V. Bhosale 《ChemistryOpen》2021,10(7):681-696
The major findings in the growing field of aggregation induced emissive (AIE) active materials for the detection of environmental toxic pollutants have been summarized and discussed in this Review article. Owing to the underlying photophysical phenomenon, fluorescent AIE active molecules show more impact on sensing applications. The major focus in current research efforts is on the development of AIE active materials such as TPE based organic fluorescent molecules, metal organic framework, and polymers that can be employed for the detection of toxic pollutants such as CN−, NO2−, Hg2+, Cd2+, As3+, As5+, F−, Pb2+, Sb3+ ions. 相似文献
90.
The photoluminescence (PL) and optical properties of CdS nanoparticles prepared by the solid-state method at low temperature have been discussed. The effects of NaCl and anionic surfactant SDBS (sodium dodecylbenzene sulfonate) on the luminescent properties of CdS nanophosphors prepared using this method, without the inert gas or the H2S environment, were studied separately. The synthesized products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), field emission scanning electron microscope (FESEM), and energy dispersive X-ray spectroscopy (EDAX). UV–VIS absorption and PL spectra were also studied. XRD studies confirmed the single-phase formation of CdS nanoparticles. TEM micrograph revealed the formation of nearly spherical nanoparticles with a diameter of 2.5 nm. The PL emission for the CdS shows the main peak at 560 nm with a shoulder at 624 nm, with an increase in the PL intensity after the addition of SDBS. The effect of Mn doping on PL intensity has also been investigated. The PL spectra show that the emission intensity decreases as the dopant concentration increases. 相似文献