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71.
Kovala-Demertzi Dimitra Demertzis Mavroudis Yadav Paras Nath Castiñeiras Alfonso West 《Transition Metal Chemistry》1999,24(6):642-647
The synthesis, as well as spectral and structural characterization, of (2-benzoylpyridine-N(4)-methyl-N(4)-phenylthiosemicarbazonato)chloropalladium(II), [Pd(Bz4MePh)Cl], is described. The unit cell contains two crystallographically independent molecules [Pd(1)(Bz4MePh)Cl], (1), and [Pd(2)(Bz4MePh)Cl], (2), stabilized by intra- and intermolecular hydrogen bonding. The distance between the Pd(1) and Pd(2) centres is 3.5038(11) Å. The spectroscopic techniques used in this study are the following: u.v.-visible, i.r. and 1H n.m.r. The protonation constants, determined spectrophotometrically, of the uncoordinated HBz4MePh are pKa1 = 10.82 ± 0.03 and pKa2 = 4.09 ± 0.02. 相似文献
72.
73.
Manoj Kumar Anant Deshpande Chintan Gupta A. K. Biswas A. K. Nath 《Journal of Chemical Sciences》2002,114(6):659-673
Selective multi-photon dissociation (MPD) of Freon-22 (CF2HC1) molecules has been carried out using a TEA CO2 laser at various CO2 laser lines (9P(20)-9P(26)) in order to maximize the yield of C-13 isotope in the product (C2F4) at an enrichment factor of 100. The effects of laser pulse tail due to the presence of N2 in the laser mixture on the enrichment factor and yield of C-13 are investigated. It is found that the addition of a small
amount of N2 is possible in the laser mixture without a significant drop in the yield at desired enrichment factor. Addition of a small
amount of N2 improves the laser efficiency considerably. At a given pulse energy, a slight change in the near field intensity distribution
of a laser severely affects the selectivity of C-13 isotope. The computed far-field intensity distributions of the measured
near-field intensities show marked spatial variation in the focal spots that leads to a drop in selectivity. For macroscopic
production of C-13 isotope a simple and novel multi-pass cavity has been designed and tested to focus the energy repeatedly
keeping the optimum fluence constant at each focal spot. 相似文献
74.
Mala Nath 《应用有机金属化学》2008,22(10):598-612
A comprehensive review on toxicity of organotin compounds including sources of their intake and mode of action, and cardiovascular activity of organotin compounds is presented. Further research to develop novel useful organotin compounds having hypertensive activity needs to be carried out. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
75.
The interaction of Me2Sn(IV)2+ and Me3Sn(IV)+ with a prodrug, sodium 2-mercaptoethane sulfonate (HSCH2CH2SO3Na, MESNA) abbreviated as (HL), has been studied potentiometrically in aqueous solution (I = 0.1 mol·L?1 KNO3, 298 K). The concentration distribution of various species formed in the solution was studied with changes in pH (~3–11). A strong coordination of MESNA with metal through the S atom of thiol group has been found. In the Me2Sn(IV)–HL system, the species [Me2Sn(L)]+ (53.1–75.6%) is predominant at acidic pH (3.73 ± 0.02) and the species [Me2Sn(L)2OH]? (29.4–38.5%) is predominant at basic pH (10.32 ± 0.08). In contrast, for the Me3Sn(IV)+ system, [Me3SnL] (37.0–57.4%) is the major species at pH 7.65 ± 0.03 and [Me3Sn(OH)] (49.9–67.2%) and [Me3Sn(L)(OH)]? (30.2–46.5%) are the major species at pH 11.05 ± 0.01. However, at physiological pH (7.01 ± 0.32), in both (1:1) and (1:2) Me2Sn(IV)–HL systems, the species [Me2Sn(L)(OH)] (67.2–89.9%) is predominant, whereas for Me3Sn(IV)–HL (1:1) and (1:2) systems, [Me3Sn(OH)] (53.5%) and [Me3SnL] (56.8%) are the respective predominant species. In order to characterize the possible geometry of the proposed complex species, multinuclear (1H, 13C and 119Sn) NMR studies were carried out at different pHs. No polymeric species were detected in the experimental pH range. 相似文献
76.
Similarity solutions for the flow of a non-ideal gas behind a strong exponential shock driven out by a piston (cylindrical
or spherical) moving with time according to an exponential law are obtained. Similarity solutions exist only when the surrounding
medium is of constant density. Solutions are obtained, in both the cases, when the flow between the shock and the piston is
isothermal or adiabatic. It is found that the assumption of zero temperature gradient brings a profound change in the density
distribution as compare to that of the adiabatic case. Effects of the non-idealness of the gas on the flow-field between the
shock and the piston are investigated. The variations of density-ratio across the shock and the location of the piston with
the parameter of non-idealness of the gas are also obtained. 相似文献
77.
Y. Nath 《International Journal of Non》1982,17(4):285-296
The von Kármán type partial differential equations governing non-linear dynamic behaviour of circular plates resting on Winkler and Pasternak elastic foundations have been analysed analytically. The space and time-wise integrations have been carried out employing the Chebyshev polynomials and implicit Houbolt techniques, respectively. The influence of foundation parameters K and G on the large amplitude response of circular plates subjected to step function loads has been studied for both the clamped immovable as well as simply supported immovable edge conditions. Foundation parameters K and G have been determined for the minimax central response. For all values of K,values of G should be between 30 and 40 for the clamped circular plates and the value of G should be a maximum for the simply supported circular plates. 相似文献
78.
Sanjay K. Bharti Saurabh K. Patel Gopal Nath Ragini Tilak Sushil K. Singh 《Transition Metal Chemistry》2010,35(8):917-925
Six Cu(II) complexes of Schiff base ligands of arylidene-2-(4-(4-bromo/methoxy-phenyl)thiazol-2-yl) hydrazines have been synthesized,
characterized and screened for DNA cleavage and antimicrobial activities. The chemical structures of the complexes were deduced
by physicochemical and spectroscopic methods. Elemental analyses indicated that the stoichiometry of the complexes is CuL2 (L = Schiff base ligand). The DNA cleavage activities of the complexes were evaluated by agarose gel electrophoresis in the
presence and absence of oxidant (H2O2) and free radical scavenger (DMSO). All the six complexes showed significant nuclease activity in the presence of H2O2, and two of the complexes showed moderate nuclease activity even in the absence of oxidant. The complexes did not show nuclease
activity in the presence of free radical scavenger. The compounds were tested for activity against selected bacteria and fungi. 相似文献
79.
Kinsuk Das Tarak Nath Mandal Somnath Roy Samik Gupta Anil Kumar Barik Partha Mitra Arnold L. Rheingold Susanta Kumar Kar 《Polyhedron》2010
The varying coordination modes of the title ligand, L [5-methyl-1-(pyridin-2-yl)-N′-[pyridin-2-ylmethylidene]pyrazole-3-carbohydrazide] towards the different metal centers is reported by preparation and characterization of Cu(II), Zn(II) and Cd(II) complexes, [Cu(L)NO3.H2O](NO3) (1) [Zn(L)2](ClO4)2·2DMF (2) and [Cd(L)(I)2] (3) respectively. In 1, the neutral ligand serves as tetradentate 4 N donor where both pyridine and pyrazole nitrogen atoms of pyridyl–pyrazole part are coordinatively active, leaving the carbonyl oxygen of the carbohydrazide part inactive. The same pyridine and pyrazole N atoms remain abstained from the coordination process towards the Zn(II) and Cd(II) metal centers. For 2 and 3 the ligand behaves as a tridentate NNO donor where the two nitrogen atoms come from azomethine, pyridine of pyridine-2-carbaldehyde parts and O from carbonyl oxygen atoms (carbohydrazide part). The complex 1 and 2 are distorted octahedral while complex 3 adopts distorted square pyramidal geometry. All the complexes are X-ray crystallographically characterized. 相似文献
80.