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711.
Sarma TK Chowdhury D Paul A Chattopadhyay A 《Chemical communications (Cambridge, England)》2002,(10):1048-1049
We report a new method of synthesis of an Au nanoparticle-conductive polyaniline composite by using H2O2 both for reduction of HAuCl4 and polymerization of aniline in the same aqueous medium: the electrical conductivity of the composite has been measured to be two orders of magnitude higher than the polymer itself. 相似文献
712.
Kuladip Sarma 《Tetrahedron letters》2007,48(38):6776-6778
The combined advantages of using an enzyme immobilized lipase from Pseudomonas sp [PSLG6], hydrogen peroxide, ethyl acetate and microwave irradiation for the dihydroxylation of olefins are reported. 相似文献
713.
Summary A convenient method for preparing nickel(II) thiocyanate is described. Some new compounds containing nickel thiocyanate and ligands, such as OPPh3, OAsPh3, bipy, Me2NH, Et3N or N2H4 are reported, together with their structures and the nature of the bond between the thiocyanate and the metal, which has been determined by physical and chemical methods. 相似文献
714.
Henry G. Kuivila John L. Considine Ramaswamy H. Sarma Richard J. Mynott 《Journal of organometallic chemistry》1976,111(2):179-196
Carbon-13 NMR parameters for 33 organotin compounds with a variety of structurul features were investigated in order to obtain information about the relationship between their structure and 13C NMR parameters. It was found that the substitution of a proton by a trialkyltin group generally produces an upfield shift for the directly bonded carbon. The γ-nuclei usually resonate at lower fields except where there is appreciable steric strain while the β-carbons undergo relatively constant shifts of approximately 3.5 to 4.5 ppm to lower fields. The magnitude of direct bond coupling Jz-sfnc;1J(119Sn13C)z-sfnc; is influenced by the hybridization of the tin and the directly attached carbon atoms. In rigid organitins, the vicinal coupling constants show a Karplus type variation. In aliphatic organotins, the values of the vicinal119Sn13C coupling indicates a flexible molecular framework with a clear cut preference for certain conformations. 相似文献
715.
Emission properties of manganese-doped ZnS nanocrystals 总被引:1,自引:0,他引:1
Sapra S Prakash A Ghangrekar A Periasamy N Sarma DD 《The journal of physical chemistry. B》2005,109(5):1663-1668
We have performed steady-state and time-resolved fluorescence studies on undoped and Mn-doped ZnS nanocrystals with approximately 16 A diameter. While there is no band-edge emission, the intensity of the steady-state blue fluorescence from ZnS surface states decreases upon Mn incorporation, which gives rise to an orange emission. These results show that Mn incorporation competes very effectively with the donor-acceptor surface states for the energy transfer from the electron-hole pair excited across the band gap. In both undoped and doped samples, the time-resolved fluorescence studies establish the presence of a distribution of decay lifetimes possibly due to a number of emission centers in the nanocrystals. A faster short-time decay of the blue emission in the Mn-doped samples compared to that in the undoped sample suggests an additional decay channel for the surface states via an energy transfer from these states to the dopant levels. 相似文献
716.
Studies of valence bands and core levels of solids by photoelectron spectroscopy are described at length. Satellite phenomena in the core level spectra have been discussed in some detail and it has been pointed out that the intensity of satellites appearing next to metal and ligand core levels critically depends on the metal-ligand overlap. Use of photoelectron spectroscopy in investigating metal-insulator transitions and spin-state transitions in solids is examined. It is shown that relative intensities of metal Auger lines in transition metal oxides and other systems provide valuable information on the valence bands. Occurrence of interatomic Auger transitions in competition with intraatomic transitions is discussed. Applications of electron energy loss spectroscopy and other techniques of electron spectroscopy in the study of gas-solid interactions are briefly presented. 相似文献
717.
In the presence of other rare earths, cerium is best identified with redox indicators. p-Sulfanilic acid is a fairly specific indicator for cerium(IV), giving a red coloration with more than 6 p.p.m. o-Tolidine and diphenylamine sulfonate can identify smaller amounts of cerium(IV), but many oxidants interfere. 相似文献
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