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排序方式: 共有127条查询结果,搜索用时 15 毫秒
11.
Mohammad Shakir Shahul Hameed Farha Firdaus Saji P. Varkey 《Transition Metal Chemistry》1995,20(2):142-143
Summary Adducts of dichlorosulphato bis(1,3-propylenediamine)-metal(II) complexes with dialkyltin dichlorides, [R2Sn(MeCN) 2]2[M(NH(CH2)3NH)2(SO3Cl)2] (M = Cr, Fe, Co, Ni or Cu; R = Me or n-Bu) have been prepared. The positive shift in the symmetric SO3 stretch and splitting of the doubly degenerate (E) modes in their i.r. spectra suggest a covalent linkage for the SO3Cl– group. The adducts are non-electrolytes; magnetic moments and ligand field data suggest that each SO3Cl– group is monodentate, generating an octahedral geometry around the metal ions, except for NiII where tetragonal distortion is observed.Author to whom all correspondence should be directed. 相似文献
12.
Mohammad Shakir Prashant Kumar Sharma Summaiya Hanif Musheer Ahmad 《Journal of Coordination Chemistry》2017,70(15):2625-2643
Dinuclear tin(IV) dicarboxylate complexes of the types [(n-Bu)2Sn(oda)(4-pic)]2·2H2O (1) and [(n-Bu)2Sn(pda)(H2O)]2 (2) [H2oda = oxydiacetic acid; H2pda = pyridine 2,6-dicarboxylic acid) were synthesized and characterized via physicochemical and spectroscopic studies. The spectroscopic results indicated that Sn is seven-coordinate having pentagonal bipyramidal (pbp) geometry in both complexes. The X-ray study of complex 2 further specified pentagonal bipyramidal geometry with dinuclear structural arrangement due to the involvement of carboxylate bridges formed by pda2? moiety. The crystal structure is further stabilized by different weak interactions viz., C–C?H, C–C?O, C–H?O, C–C?O, and C–H?H. These interactions are further supported by Hirshfeld surface analysis along with 2-D fingerprint plots of complex 2. In vitro DNA-binding studies of both complexes were evaluated using spectroscopic techniques (absorbance and fluorescence) which ascertained optimum binding affinity of both complexes. However, cleavage activity of the complexes was assessed using supercoiled DNA (pBR322) via gel electrophoresis technique which demonstrated significant cleavage pattern of both complexes at different concentrations. Furthermore, chemotherapeutic potential of complexes 1 and 2 against MCF-7 and Hep carcinoma cell lines also suggested significant antiproliferative effect of complexes. These results revealed momentous exploration of drug–DNA interactions which may engender new insinuation for the advancement of metallo-pharmaceuticals. 相似文献
13.
V. Ganesh Ch. Snehalatha ReddyMohd. Shakir M.A. WahabG. Bhagavannarayana K. Kishan Rao 《Physica B: Condensed Matter》2011,406(2):259-264
〈1 1 1〉 oriented bis thiourea cadmium acetate (BTCA) crystal of diameter 15 mm and length 45 mm was grown for the first time by the unidirectional Sankaranarayanan-Ramasamy (SR) method. The conventional and SR method grown BTCA crystals were characterized by using high-resolution X-ray diffraction (HRXRD), chemical etching, Vickers microhardness, UV-vis, dielectric studies and differential scanning calorimetry. The HRXRD analysis indicates that the crystalline perfection of SR method grown crystal is good without having any low angle internal structural grain boundaries. The transmittance of SR method grown BTCA is 14% higher than that of conventional grown crystal. The dielectric constant was higher and the dielectric loss was less in SR method grown crystal. The crystals grown by SR method possess less dislocation density and higher microhardness. 相似文献
14.
Shuaib Urooj Hussain Tousif Ahmad Riaz Imranullah M. Amjad Muhammad Yasin Amna Shakir Imran Kang Dae Joon 《Journal of Solid State Electrochemistry》2023,27(3):715-725
Journal of Solid State Electrochemistry - Nowadays, metal hexacyanoferrate/metal oxide composites have attracted intense interest as an electrode material for supercapacitor applications due to... 相似文献
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16.
Khan Tahir Ali Hasan Syed Sirajul Varkey Saji P. Rather Manzoor Ahmad Jahan Nafees Shakir Mohammad 《Transition Metal Chemistry》1997,22(1):4-8
A new class of tetraiminetetraamide macrocyclic (Ph4[20]tetraene, N8O4, and Ph6[20]tetraene, N8O4) complexes have been prepared through the metal ion controlled reaction of 1,2-diphenylethane-1,2-dione dihydrazone (DPEDDH) with succinic acid [ML1X2] or phthalic acid [ML2X2] [M=Mn, Co, Ni, Cu or Zn; X=Cl or NO3]. The structures of the complexes have been elucidated on the basis of i.r, 1H-n.m.r, e.p.r. and electronic spectral data and conductance, as well as magnetic, properties. An octahedral geometry is assigned for all the complexes, involving coordination of the all-imine nitrogens. 相似文献
17.
Sami A. Shakir 《Physics letters. A》1983,93(9):510-512
We describe two methods for employing materials with giant Kerr nonlinearities for modulating waveguides. A beam, of relatively intense light, is used to vary the propagation constant of a waveguide with the guiding layer, or the substrate, made from a nonlinear material. 相似文献
18.
Mohd. Shakir S.K. KushwahaK.K. Maurya Manju AroraG. Bhagavannarayana 《Journal of Crystal Growth》2009,311(15):3871-3875
Remarkable second-harmonic generation (SHG) efficiency has been observed in the glycine picrate (GP) though it crystallizes in centrosymmetric structure. Bulk single crystals of GP with a good size of ~20×10×3 mm3 have been successfully grown by the slow cooling method in aqueous medium. Powder X-ray diffraction (PXRD), Fourier transform infrared (FT-IR) and FT-Raman studies have confirmed, respectively, the crystal structure and functional groups of the grown crystal. Crystalline perfection of single crystals has been evaluated by high-resolution X-ray diffractometry (HRXRD) using a multicrystal X-ray diffractometer and found that the grown crystals are nearly perfect. Nonlinear optical (NLO) behavior of glycine picrate crystals has been studied for the first time by Kurtz powder technique and its second-harmonic generation efficiency is found to be 2.34 times higher than that of KDP. Transparency of crystals in UV–vis–NIR region has also been studied. Dielectric measurements have been carried out using an impedance analyzer over a wide range of frequency (100 Hz–3 MHz) at room temperature. The slight decrease in dielectric constant has been observed as the frequency is increased and the dielectric loss is very low for the entire frequency range. The ac conductivity is almost constant up to 1 MHz and sudden increase has been observed above this frequency. 相似文献
19.
Ion, precipitate and adsorbing colloid flotation of cobalt(II) have been investigated at different pH values, using N-dodecylpyridinium chloride (DPCl), A strong cationic surfactant, and sodium lauryl sulfate (NaLS), a strong anionic surfactant, as collectors. In case of adsorbing colloid flotation, hydrous manganese dioxide was used as an adsorbent. The precipitate flotation curves experimentally obtained with the two tested collectors were compared with the corresponding theoretical one calculated from the data published for Co(II) hydrolysis. The effects of the collector concentration, ageing of the water-MnO2–Co(II) system, bubbling time period, cobalt(II) concentration and foreign salts on the percent removal of Co(II) by adsorbing colloid flotation using DPCl as collector were determined. Removals approaching 100% could be achieved under the optimum conditions. 相似文献
20.
The liquid-liquid extraction, ion and precipitate flotation of Co(II) from chloride media of 1·10–4M initial Co(II) concentration and =0.1 have been investigated using decanoic acid and the results are compared. Organic solvents used were chloroform in the case of liquid-liquid extraction and ethanol (used as a solvent for the collector and a frother) in the case of flotation. From the results it appears that liquid-liquid extraction takes place through the formation of the complex: (CoR2)2(HR)2 but flotation occurs through the formation of a surface active product which has the empirical formula CoR2. The effects of pH and of decanoic acid concentration on the three separation processes were also investigated and the results discussed. Good agreement was observed between the experimental precipitate flotation curves and the theoretical curve calculated from the data published for Co(II) hydrolysis. 相似文献