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71.
Summary The purple violet ruthenium(III)-diphenylcarbazone complex which is formed at p
h
5–7, and has an absorption maximum at 530 nm with molar absorption coefficient 16.2·104l.cm–1.mole–1 is suggested for the estimation of 20–125g ruthenium(III) spectrophotometrically in 30–60% ethanol. The complex is stable over p
h
range 3.2–8.4. The limits of interference due to foreign ions have been studied.
Zusammenfassung Der bei p h 5 bis7 entstehende Ruthenium(III)-Diphenylcarbazon-Komplex hat ein Absorptionsmaximum bei 530 nm und einen Absorptionskoeffizienten von 16,2·104 l.cm–1.Mol–1. Die spektrophotometrische Bestimmung von 20 bis 125g Ruthenium(III) in 30 bis 60%igem Äthanol mit Hilfe dieses zwischen p h 3,2 und 8,4 beständigen Komplexes wurde vorgeschlagen. Die Störung durch Fremdionen wurde geprüft.相似文献
72.
Smt.S.R. Bharadwaj M.S. Chandrasekharaiah M.S. Gill S.C. Jain 《Thermochimica Acta》1983,71(3):247-255
As cesium hexanitratouranium(IV), Cs2U(NO3)6, has the same Cs:U stoichiometry as that of Cs2UO4, thermal decomposition of this nitrato complex in air and nitrogen was studied in detail as a possible alternate method of preparing pure Cs2UO4. The volatility of cesium nitrate, which is one of the intermediate products, changed this Cs:U ratio during thermal decomposition. Hence, only Cs2U2O7 was obtained on heating the sample to 775 K or higher. A scheme for the thermal decomposition of Cs2U(NO3)6 is given by combining the observed TG, XRD and IR data. 相似文献
73.
The technique of three-phase partitioning (TPP) was used to purify the green fluorescent protein (GFP) in a single step. TPP uses a combination of ammonium sulphate and tert-butanol to precipitate proteins from their crude extracts. In the first round of TPP with 20% ammonium sulphate saturation at the ratio of crude to tert-butanol 1:1 (v/v), most of the GFP remains in the lower aqueous phase. When subjected to a second round of TPP with 60% ammonium sulphate saturation at the ratio of crude to tert-butanol 1:2 (v/v) gives 78% recovery of GFP with a 20-fold purification. The sodium dodecyl sulphate-polyacrylamide gel electrophoretic (SDS-PAGE) analysis of purified preparation shows single band. The fluorescence excitation and emission spectra agreed with values reported in literature. 相似文献
74.
The article reviews in brief, thede novo group additivity approach and, at length, the different topological approaches to obtain predictive and internally consistent
correlations between various properties and structural features of molecules. The stress has mainly been on the molecular
connectivity method. A new rational scheme for nomenclature of connectivity indices of different orders and types is introduced.
The concept of the perturbation connectivity parameter developed by us recently has been applied to obtain correlations for
molar refraction, boiling point, molar volume, heat of atomisation, heat of combustion, heat of vaporisation, magnetic susceptibility
and critical constants of alkanes, alcohols and alkylbenzenes. A comparative study of various approaches reveals that the
present perturbation topological approach has an edge over other similar methods. 相似文献
75.
[structure: see text] Receptors based on a tetraphenylporphyrin scaffold bearing different charged and hydrophobic groups have been synthesized. The interactions of these with horse heart cytochrome c were studied by fluorescence spectroscopy. Receptor 4 was identified to be the strongest synthetic receptor (K(d) = 20 nM) for cytochrome c. The differences in affinity among the receptors reflected a dependence on the number of anionic and hydrophobic groups. 相似文献
76.
Sengupta Soumitra K. Pandey Om P. Srivastava Bimal K. Sharma Vinod K. 《Transition Metal Chemistry》1998,23(4):349-353
The reactions of bis(cyclopentadienyl)titanium(IV)/zirconium(IV) dichloride with a new class of organometallic thiosemicarbazones (LH), derived by condensing acetylferrocene with substituted thiosemicarbazides, have been studied and two types of bimetallic products, viz. [Cp2M(L)Cl] (M = Ti or Zr) and [CpZr(L)3], have been isolated. On the basis of various physicochemical and spectral studies, five- and seven-coordinate structures have been assigned to these derivatives, respectively. Attempts have been made to establish a correlation between biological activity and the structures of the products. 相似文献
77.
Summary Fifteen palladium(II) square-planar complexes containing monodentate and/or bidentate anti- and syn-furan-2-aldoxime (FDH) have been isolated and characterized by elemental analysis, molecular weight determination, conductance studies, magnetic moments and i.r. spectral studies. The monodentate ligand coordinates through the nitrogen atom while the bidentate ligand coordinates through the furan oxygen atom and the nitrogen atom. The C-O-C stretching frequency of the furan ring may be taken as the criterion for the denticity of this ligand and is observed at 1240 and 1270 cm– in anti- and syn-furan-2-aldoxime respectively. A shift to lower frequency occurs (in the complex) if the ligand is bidentate, however this frequency is unaffected if the ligand is monodentate. 相似文献
78.
B. K. Jha B. D. Kulkarni M. P. Vinod K. Vijayamohanan 《Chemical physics letters》1995,240(5-6):442-448
The electrochemical behavior of ferrocene in an aqueous microemulsion (pentan-1-ol/sodium dodecyl sulfate (SDS)/aq. H2SO4) has been studied using an ultramicroelectrode. Contrary to the generally expected reversible peak, the experiments show the presence of a second oxidation peak during the reverse scan at low scan rates where the peak corresponding to ferricinium ion reduction is nearly absent along with the unanticipated appearance of a current dip. These observations are rationalized using a novel type of coupling between heterogeneous (electrochemical) and homogeneous (chemical) electron transfer processes. The composition of the medium, especially the acid concentration, affects the electron transfer of the solubilized probe and there exists a threshold acid concentration for achieving maximum anodic peak current. 相似文献
79.
A.C. JainS.M. Jain 《Tetrahedron》1972,28(4):981-986
2,4-Dihydroxyphenyl benzyl ketone (I) condenses with 2-methyl but-3-en-2-ol in the presence of boron trifluoride etherate to afford a mixture of 3-C-, 5-C- and 3,5-di C C-prenyl derivatives separable by chromatography. The above mixture without the 5-C-prenyl but with the 4-O-prenyl derivative results when ketone I is treated with prenyl bromide in the presence of methanolic potash. 3-C-(III a) and 5-C-(IV) prenyl derivatives undergo ready oxidative cyclization with DDQ to yield the corresponding pyrano derivatives VIII and XII respectively which form good starting materials for various isoflavone condensations. Thus both linear and angular 6″,6″-dimethyl pyrano-isoflavones and their 2-methyl and 2-phenyl analogues have been synthesized. 相似文献
80.
Summary The stability of emulsion of Toluene in water stabilized by partially flocculated ferric hydroxide sol has been studied. The
size of the emulsion droplets as determined by size frequency analysis is found to be of 1.1 μ radius. The flocculation studies were carried out haemocytometrically at different amount of electrolytes and at different
pH values. The electrokinetic potential ‘ζ’ was determined micro-electrophoretically at different amounts of electrolytes and
also at different pH's. In the case of tri and tetra valent anions the charge reversal was observed. In the light of the D.V.O. theory the interaction
energy profiles were drawn and 2–6 kT deep secondary minima obtained showing thereby the occurrence of reversible flocculation. Degree of aggregation has been
calculated theoretically at different values of ‘A’ and the value of A was found to be 1.0×10−12 erg to fit the value of degree of aggregation obtained haemocytometrically. The charge densities and binding parameters have
also been calculated. 相似文献