Raman and resonance-Raman spectra of CsI/I−3

Raman and resonance-Raman spectra of the I^?₃ ion isolated within CsI crystals have been studied using 647 nm and 488 nm exciting radiation. Sample temperatures between 300 and 20 K have been used. Eleven overtones of the symmetric stretching mode (nν₁) have been observed in the resonance-Raman spectrum excited by the 488 nm Ar⁺ laser line. Bands centred at 153, 170, 264 and 304 cm^?1 have been assigned as ν₃, 2ν₂, ν₁+ν₃ and 2ν₃(Σ⁺) respectively. The remaining structure between the nν₁ lines has been assigned as due to combinations of these lines with the lattice vibrations of the CsI crystal.     

RESEARCH ON 2-(2'-SUBSTITUTED VINYL)-5-BIPHENYLYL OXAZOLES

Fifteen of the 2-(2'-substituted vinyl)-5-biphenylyl oxazoles were synthesized respectively by the condensation of corresponding 2-methyl-5-biphenylyl oxazole with benzaldehyde,substituted benzaldehydes or furfural in the presence of alkali or acid.Their m.p.,infrared spectra,λmax of UV spectra and fluorescence spectra,fluorescence quantum yields as well as laser conversion efficiency of the compounds are listed in tables.     

Mossbauer Study of the Effect of Intraligand Substituents on the Spin Crossover in Solid (Dithiocyanato)BIS(N-Substituted-Phenyl-2-Pyridinaldimine) Iron (II)

The spin transition of high-spin (^sT₂?)low-spin (¹A₁) of (dithiocyanato) (N-phenyl-2-pyridinaldimine) iron (II) complexes can be altered by substituents on the phenyl ring. Mössbauer spectra at 78K for the 4-substituted derivatives (with the exception of the 4-OH-substituted derivative) indicate that the fraction of low-spin states increases with decreasing substituent electron-withdrawing ability, as measured by the Hammet σ constant (4-OCH₃<4-CH₃CONH 4-C₆H₅<4-CH₃<4-H<4-Cl<4-NO₂). In addition, the effect of methyl-substitution at the ortho-, meta- or paraposition of the phenyl ring on the spin transition was examined. Mössbauer spectra of these methyl-substituted complexes reveal quite different spin equilibria.     

示波极谱滴定法测定盐酸氯喘等药物

盐酸氯喘,盐酸阿米替林和维生系B_6都是常用药物,中国药典和上海市药品标准用非水滴定法测定它们的含量,比较麻烦。梁云爱等用示波滴定法测定维生素B_6的含量,采用NaoH中和滴定测定盐酸吡多醇中的盐酸部分。我们在一定pH值的醋酸—     

The Permanganate Oxidation of Triethylamine; Evidence for the Formation of Manganate Ion in Potassium Permanganate/Triethylamine Reagent

The active oxidant of KMnO_4/Et₃N reagent has been verified as potassium manganate by ultraviolet spectrometry, and the final oxidation product as manganese(IV) oxide by iodometric titration.     

Synthesis and Spectra of Bichromophore Compounds Containing Oxazole or Oxadiazole Ring

Fifteen of the bichromophore compounds containing oxazole or oxidation ring have been synthesized. Their structures have been identified by IR, 1H NMR spectra and elemental analysis. The UV spectra, fluorescence spectra and the laser conversion efficiencies have been determined . The results of determination show that the absorption and emission spectra Pf the bichromophore compounds are different from those of the corresponding single chromophore compounds.     

Guided modes below the bulk plasma frequency

We present the results of calculations for a waveguide in which the dielectric constant ? decreases exponentially from a positive value at the surface to a negative value in the bulk, the guided waves propagating perpendicular to ▽?. Both TM and TE modes are found, each having some unusual properties as compared with modes in the same guides above the plasma frequency. These modes could be realized at 10.6 μm in suitably doped GaAs.     

Plasmon dispersion in metallic lithium–ammonia solutions

Inelastic X-ray scattering spectra of lithium (Li)–ammonia solutions with concentrations of 9, 13, and 17 mol.% metal have been measured with 0.05- and 0.38-eV resolution for momentum transfer between 0.18 and 0.56 Å⁻¹. The peak growing with Li-concentration was found around 2 eV, and was assigned to the plasmon of delocalized Li-2s electrons. The plasmon shows a positive dispersion, indicating that exchange–correlation effects in actual nearly free electrons are considerably smaller than expected.