摘要:

The Chemisorption and conformation of milrinone injection on HNO3etched silver foil and chemically reduced silver films have been investigated by Fourier transform Surface Enhanced Raman Scattering spectroscopy (FT-SERS).

ISSN:0038-7010    

DOI:10.1080/00387019808007391

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

The effect of nitric acid/organic aerosols on the emission intensity of metals from the first row transition series, plus Cd and Pb was investigated. The addition of organic solvents to reference solutions diminished the aerosol mean drop size, by reducing the surface tension of the solutions. Correlation between signal intensity and BEC with the main physical characteristics (surface tension and viscosity) of the nitric acid/acetic acid and nitric acid/alcohol solutions was studied. Analytical curves (0–2.0 fig ml−1) were evaluated using a matrix matching procedure, and detection limits indicated an improvement (ca 40%) in analytical performance as well as in linearity, sensitivity and precision.

ISSN:0038-7010    

DOI:10.1080/00387019808007392

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

TheInteraction Vector Model(IVM) is used to study the intensity of the near UV transition of phenolates. Thirteen phenolates have been studied using the phenolate anion as a reference. The modulus of the-O−⇔-CH3ortho interaction vector has been adapted to an unusual strong interaction. The π donating effect of-O−tends to blur the smaller π donating effect of the methyl substituents, and tends to quench the effect on intensity of the methyl in the para position.

ISSN:0038-7010    

DOI:10.1080/00387019808007393

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

The binding of γ-picoline to horse heart ferricytochromec(cytc) by displacing methionine-80 has been studied using two dimensional exchange spectroscopy (EXSY) method. Some hyperfine shifted resonances arising from heme peripheral protons in the γ-picoline complex of cytc(γ-MePy·cytc) have been assigned. The rate and equilibrium constants of γ-picoline binding to cytchave been measured and the thermodynamic values of ΔH°, ΔS° and the activation energy Eafor the forward reaction have been obtained. The patterns of the hyperfine shifts of γ-MePy·cytchave been illustrated and the reason for the low affinity of γ-picoline to cytchas been discussed.

ISSN:0038-7010    

DOI:10.1080/00387019808007394

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

The hydrogen bond complexes between phenols and 2,3-bis(2-pyridyl)-pyrazine BPP) are investigated by infrared spectroscopy in carbon tetrachloride solution. The formation constants for the complexes of 1–1 stoichiometry are higher than those predicted from the pKaof BPP. This is also the case for other N-heteroaromatic bases (pyridazine, 2,2′-bipyrimidine) characterized by two vicinal equivalent nitrogen atoms. The thermodynamic and infrared data of the complexes show that BPP cannot be considered as a proton sponge.

ISSN:0038-7010    

DOI:10.1080/00387019808007395

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

Singlet energy transfer between seven derivatives of perylene diimides and cobalt ions are studied. Energy transfer quenching by cobalt ions is observed for all of the perylene diimides. The rate of bimolecular quenching is found to be about, kq≅ 1010M−1s−1, only the N-naphthyl substitution lowered the rates to the range of, kq≅ 109M−1s−1. The critical transfer distances, Ro(5.8–10.4 A°), calculated from donor emission and acceptor absorption spectra, are attributed to a Forster resonance energy transfer process.

ISSN:0038-7010    

DOI:10.1080/00387019808007396

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

Schiff bases of the type salicylidene 2-aminobenzothiazole and o-nitrobenzylidene 2-aminobenzothiazole were prepared by condensation of 2-aminobenzothiazole with salicylaldehyde and o-nitrobenzaldehyde. The bases react with cobalt(II), nickel(II) and copper(II) chlorides to give 1:1 and 1:2 complexes. Electronic spectra, magnetic susceptibility measurements and infrared data are used to infer the structures. The thermal decomposition of the complexes and evaluation of the thermodynamic parameters are also reported.

ISSN:0038-7010    

DOI:10.1080/00387019808007397

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

We have measured the photoluminescence spectra of nanometric scale X1-Y2SiO5:Eux. The spectra were recorded at 15K and room temperature using site selective excitation by a dye laser in addition to conventional UV excitation. We found that at low temperature there is a pronounced excitation transfer from site 2→1. The transfer rate increases rapidly with increasing concentration and for x=0.7 no fluorescence from site 2 can be observed. Decaycurve measurement revealed this transfer process directly. The lifetimes of the5Do levels of the two sites were also measured as a function of Eu3+concentration. The results show that the lifetimes of the5D0level of site 2 decreases with increasing concentration. The mechanism of the excitation transfer is discussed. Wavelengths of the5D0→7D0–4transitions of the two sites were also tabulated.

ISSN:0038-7010    

DOI:10.1080/00387019808007398

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

The crystal structure of the title compound, C17H13N5O4, has been determined by single crystal x-ray diffraction at room temperature. The molecule is not planar, with dihedral angles of 7.2(1)° between the quinoline ring and N-methylhydrazone group, and 17.45(2)° between the N-methylhydrazone group and the phenyl ring. The crystal parameters of this compound are as follows: monoclinic P 21/n, a=9.525(2)Å, b = 15.192(2) Å, c = 11.302(2) A, β = 94.722(3)°, V = 1629.8(6) Å3, Z = 4, Dx = 1.432 g/cm3, F(000) = 728, λ (MoKα) = 0.71070 Å, μ = 0.106 mm−1, Rint= 0.017. The structure was solved by SHELXS-86 and refined by SHELXL-93. R = 0.07 for 2438 observed reflections with I > 2σ (I).

ISSN:0038-7010    

DOI:10.1080/00387019808007399

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

We report here the preliminary results of the surface enhanced transmission infrared spectra of CH3(CH2)7Azo(CH2)3COOH monolayers on CaF2substrate which was coated by silver island films with different size and distribution. The larger enhancement of absorbance of v(C=O) in COOH residing between silver island gap and small enhancement of absorbance of vibration mode of COO−located on the silver islands are observed. It give us a direct experimental evidence of the collective electron resonance mechanism of surface enhance infrared spectroscopy (SEIRS), i.e. the decrease of the electromagnetic (EM) coupling reduces the enhancement factor of SEIRS.

ISSN:0038-7010    

DOI:10.1080/00387019808007400

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor