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N. K. Sanyal A. N. Pandey H. S. Singh B. P. Singh 《Journal of Quantitative Spectroscopy & Radiative Transfer》1970,10(12):1343-1345
The generalized mean-square amplitudes of vibration and mean amplitudes of vibration have been computed for CrO3-4, Mn18O-4, MoSe2-4 and WSe2-4 ions at three temperatures, T = 0°K, T = 298°K, T = 500°K, employing Cyvin's method. The results have been discussed in the light of atomic weight and electronegativity of the atom in the ionic system. 相似文献
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Considering quarks as dyons, we analyze different possibilities for free fractional electric charges and monopoles to coexist. For nonvanishing vacuum angle, electric charges of dyons are not exactly fractional, but carry extra charges proportional to. The average extra charge vanishes for mesons, but not for baryons. 相似文献
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Isocratic reversed-phase liquid chromatography (LC) method was developed using acetonitrile and water for the determination of diospyrin, a pharmacologically important bisnaphthoquinonoid plant-product. The method was validated for precision, accuracy and reproducibility, and was found to be linear over the concentration range of 1-1000 microg/ml; the limits of detection and quantitation were 8 and 20 ng, respectively. The technique was used to determine the amount of diospyrin in plant extracts from four climatic regions in India. It was also applied for differentiation and separation of 27 naphthyl compounds. While a composition of 50:50 was preferable for dimeric compounds, the composition 40:60 was a better choice for the monomers. Also, the isomeric alpha- and beta-naphthols and their dimers could be distinguished by conversion into the respective methyl ethers. 相似文献
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Summary 2-Aminopyridine reacts with acetylacetone in the presence of VOII, MnII, FeII, CoII, NiII, and CuII metal salts to give complexes of the type [VO(Ap2ac)2X]X and [M(Ap2ac)2X2] where (Ap2ac) is the ligand formedin situ. The complexes are characterised as distorted octahedral by analyses, conductance, molecular weight, magnetic, electronic and i.r. spectral studies. The i.r. studies reveal that two molecules of aminopyridine are joined by a molecule of acetylacetone through a three carbon atom bridge and that the ligand coordinates through the azomethine and imino nitrogen atoms, whereas pyridine does not take part in coordination. The electronic spectra have been interpreted and tentative assignments are made. In the far i.r. spectra, various metal ligand vibrations are observed and discussed. Attempts to carry out electrophilic substitutions in the complexes failed. 相似文献
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Rhenium and uranium hexafluorides oxidise iodine in iodine pentafluoride at ambient temperature to give the I2+ cation. With UF6 additional reaction occurs to give β-uranium pentafluoride as one product (J.A. Berry, A. Prescott, D.W.A. Sharp, and J.M. Winfield, ., 1977, , 247). Further work on the latter reaction together with an electronic spectroscopic study of the oxidation of I2 by phosphorus pentafluoride in IF5, suggests that the fate of the I2+ cation depends on the nature and quantity of the oxidising agent. Oxidation of I2 by PF5 can be conveniently followed by monitoring its visible spectrum. The reaction occurs over several hours and eventually an apparent equilibrium between I2 and I2+ results. Formation of I2+UF6?is rapid and, with the mole ratio UF6:I2 > 10:1, UF5 is precipitated rapidly from solution, I2+ being oxidised further, apparently to IF5. With a smaller UF6:I2 mole ratio UF5 is contaminated by I2, the latter is presumed to result from the disproportion-ation of an II or IIII fluoride.β-UF5 is very soluble in acetonitrile and reacts with thallium(I) fluoride in this solvent to give TlIUF6. It reacts with trimethyl(methoxo)silane to give (CH3)3SiF, U(OCH3)5, and an insoluble solid, believed to be a mixture of UV methoxide, fluorides. Both reactions are conveniently followed by near i.r. spectroscopy. 相似文献