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101.
Vinod K. Sharma Om P. Pandey Soumitra K. Sengupta Dost M. Halepoto 《Transition Metal Chemistry》1989,14(4):263-266
Summary The reactions of MCl3·3H2O (M=Ru, Rh or Ir) with hydrazones have been studied by three different methods and complexes of the types [M(LH2)(H2O)2]Cl3, [M(L)Cl(H2O)] and [M(LH2)Cl2]Cl·H2O have been isolated. Tentative structural conclusions are drawn for these products based upon elemental analysis, electrical conductance, magnetic moment, and i.r. and1H n.m.r. data. The thermal stability and mode of decomposition for the complexes have been studied by t.g.a., d.t.g. and d.s.c. techniques. 相似文献
102.
Surface modified ormosil nanoparticles 总被引:1,自引:0,他引:1
Organically modified silanes (ORMOSIL) such as vinyl triethoxysilane readily aggregate in the aqueous cores of reverse micelles where the triethoxysilane moieties are hydrolyzed to form a hydrated silica network and the vinyl groups protruded out from the surface of the nanoparticles toward the hydrophobic side of the micellar interface. These particles are spherical and the size distribution of the particles is relatively narrow, with an average diameter of 87 nm. Surface vinyl silica nanoparticles so formed have been oxidized to surface carboxylic silica nanoparticles, followed by chemical conjugation with polyethyleneglycol amine (PEG amine) through the ethyl-3-(3-dimethylaminopropyl) (EDCI) carbodiimide reaction. The characteristic surface groups have been identified by Fourier transform infrared spectroscopy, while the size and the morphology of the particles have been studied by dynamic light scattering and transmission electron microscopy. It has been found that about 80-85% of the carboxylic groups are PEGylated during the EDCI reaction. 相似文献
103.
Renu Sharma Santosh K. Agarwal Shikha Rawat Meena Nagar 《Transition Metal Chemistry》2006,31(2):201-206
The synthesis and characterization of some transition metal cis-3,7-dimethyl-2,6-octadiensemicarbazone (CDOSC) complexes are reported. The ligand CDOSC yields: [ML2 Cl2] and [ML2 Cl2] Cl type complexes, where M = CrIII, MnII, FeIII, CoII, NiII, CuII, ZnII, CdII and HgII, L = CDOSC. Structures of the complexes were determined using elemental analysis, molar conductivity, magnetic measurements,
i.r. and electronic, as well as n.m.r spectra. CDOSC acts as a bidentate ligand in all the complexes. All the newly synthesized
metal complexes, as well as the ligand, were screened for their antibacterial activity. All the complexes exhibit strong inhibitory
action against Gram (+) bacteria Staphylococcus aureus and Gram (−) bacteria Escherichia coli. The antibacterial activities of the complexes are stronger than those of the ligand CDOSC itself. 相似文献
104.
K. C. Mishra B. N. Dev S. M. Mohapatra W. M. Gibson T. P. Das 《Hyperfine Interactions》1983,16(1-4):997-1000
The electronic energy levels and wave functions of fluorine and chlorine atoms adsorbed at the <111> surface of silicon are obtained by the Hartree-Fock procedure applied to clusters simulating the surface structure. Minimising the total energy with respect to the positions of the halogen atoms, the Si-Cl distance in the adsorbed system was found to be in good agreement with that from a recent SEXAFS measurement, there being no corresponding data presently available for fluorine on silicon surface. The calculated19 f * nuclear quadrupole coupling constants using the electronic wave functions for SiH3F and the larger cluster Si4H9F, simulating the surface, differed substantially in contrast to the situation for the Si-F distance, indicating that the quadrupole coupling is a more sensitive indicator of the adequacy of the cluster chosen to represent the surface system. Experimental results for the coupling constants are awaited for comparison with theory. 相似文献
105.
A new and more efficient route for the conversion of the readily available (+)-Δ3-carene into (+)-trans-chrysanthemic acid is described. 相似文献
106.
(E)-4-(2',4',5'-trimethoxyphenyl)but-1,3-diene (4) and (E)-4-(2',4',5'-trimethoxyphenyl)but-1-ene (6), bioactive phenylbutanoids of Zingiber cassumunar, were synthesized exclusively with trans geometry. Treatment of methylmagnesium iodide with (E)-2',4',5'-trimethoxycinnamaldehyde (2), an oxidized product of abundantly available toxic (Z)-phenylpropanoid (1) of Acorus calamus, gave (E)-4-(2',4',5'-trimethoxyphenyl)but-3-en-2-ol (3) which upon dehydration with copper sulphate/silica gel under microwave irradiation for 3 min afforded 4 in 58% yield. Further, catalytic hydrogenation of 4 with 10% Pd/C afforded 4-(2',4',5'-trimethoxyphenyl)butane (5) which upon dehydrogenation with DDQ/SiO2 afforded hypolipidemic 6 in 54% yield. 相似文献
107.
A two-fluorophore system consisting of pyrene as donor and perylene as energy acceptor undergoes efficient energy transfer when pyrene is electronically excited. The excitation wavelength was that of pyrene and fluorescence was monitored at the emission wavelength of perylene. The fluorescence of pyrene is strongly quenched by oxygen, but that of perylene is not. The two-fluorophore system, in contrast, is very strongly quenched, with a 4-fold increase in the Stern-Volmer quenching constant as compared to the quenching of pyrene, as a result of the effect of oxygen on the formation of the donor-acceptor exciplex, and quenching by oxygen. The results are used to design a fluorescence-based optical oxygen sensor which offers a sensitivity greatly exceeding that of existing oxygen probes. 相似文献
108.
Organoboron derivatives of biologically potent β‐enamino esters of the type [Where R = CH3(1a), C2H5 (1b), C3H7(1c) and C (CH3)3 (1d)] have been prepared by the reactions of β‐enamino esters and Phenyl boronic acid [PhB (OH)2] in 1:2 molar ratio in refluxing tetrahydrofuran (THF). All these derivatives have been characterized by physico‐chemical properties, elemental analyses and molecular weight measurements. The structures of these compounds have been proposed on the basis of IR, 1H, 13C, 11B NMR spectral data and GC‐mass spectrometry. Phenyl boronic acid, β‐enamino esters and their respective phenylboronates derivatives have been screened for the antibmicrobial activities against pathogenic bacteria (B. subtilis and E. coli) and fungi (A. niger and P. peniculosum) to access their growth inhibiting potential. In addition to this, antiandrogenic effect of Ligand, LaH2 and its boron derivative (1a) has also been tested in male albino rats. 相似文献
109.
Sulphide, sulphite and thiosulphate can be determined separately or in admixture, with thallic perchlorate or sulphate in acid medium. A sample solution is rendered approximately 0.5 M in acid, 5 ml of 0.05 M KI are added and the solution is titrated to a starch end-point with thallium(III) solution. In another method an acid sample solution is titrated with thallium(III) or iodine solution in the presence of indigo carmine indicator. The end-point is improved in the presence of Co(II). 相似文献
110.
Raman spectra of NaNO2 have been studied as a function of hydrostatic pressure to 40 kbar at 295 and 348 K. Slight changes in slope of mode frequency versus pressure plots support the view that a structural anomaly exists at 9 ± 1 kbar. The absence of qualitative changes in the Raman spectra allow the space group of NaNO2 IV to be specified as one of P1, P2, B2, Pm or Bm. The Raman spectrum of NaNO3 has been studied to 87 kbar. The changes observed are fully consistent with a second-order transition to a phase with symmetry C63v, as indicated by previous X-ray work, although the transition is sluggish. 相似文献