摘要:

Starting from the Perov-Bakhshiev's frequency shift formula and using an analogy from electronics a new frequency shift formula was deduced which gives the possibility of describing the spectral shift effects in the electronic spectra observed at a great variety of the spectral-active compounds dissolved in various non-polar and polar solvents with universal or specific solvation effects.

ISSN:0038-7010    

DOI:10.1080/00387018608069302

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

The infrared and Raman spectra of polycrystalline samples of K2HPCr2O10, Na3PCr3O13.3H20, K3PCr4O16and (NH4)3PCr4O16were recorded and discussed. A general vibrational assignment for the internal vibrations of these species is proposed.

ISSN:0038-7010    

DOI:10.1080/00387018608069303

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

A spectroelectrochemical technique based on the Fourier Transform Infrared Reflection Absorption Spectroscopic (FTIR-RAS) method is described, whereby high resolutionin situvibrational spectra of electrogenerated reaction intermediates (including radicals) and species adsorbed on electrode surfaces are obtained. Theoretical and experimental aspects of the method in a single reflection mode are discussed. Details of the cell design and the optimization of the operational parameters for running the FT-IR spectrometer in the RAS mode are also described. Apart from the potential of this technique to identify adsorbed species through their vibrational spectra, it can also be used to determine the orientation of the adsorbed species on the electrode surface by making use of surface selection rules. Using this technique, it has been possible to record the spectra of molecules adsorbed from aqueous and non aqueous media on metal and carbon electrodes. It has been possible to distinguish the vibrational spectra of adsorbed molecules from those in the bulk. Various systems covering a wide range of molecules have been studied and the potential of the technique as a method for the characterization of the electrode-electrolyte interface has been demonstrated.

ISSN:0038-7010    

DOI:10.1080/00387018608069304

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Infrared and Raman spectra were obtained for 4,4-dimethylheptane and were interpreted with the aid of normal coordinate calculations. It was shown that this compound exists in three conformations. Force constant values transferred from dimethylpentanes resulted in an overall average difference between observed and calculated wavenumbers of 4.5 cm−1for the three conformers.

ISSN:0038-7010    

DOI:10.1080/00387018608069305

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

The uv spectra of several nitroimidazoles are reported. These experimental results are interpreted using CNDO/S method (Complete Neglect of Differential Overlap for Spectroscopy). Calculations show that observed transitions are π→π* type transitions.

ISSN:0038-7010    

DOI:10.1080/00387018608069306

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

The two sets of diastereomeric hydrogen atomscisandtransto the carboxylate of 1-aminocyclopropane-1-carboxylic acid (ACC) were differentiated by a1H-nmr study. The measurement of the1H-nmr spectrum of ACC at pH 3.8 during the successive addition of non-chiral lanthanide reagents such as Eu(NO3)3, Pr(NO3)3or Gd(NO3)3demonstrated that the hydrogen atomscisto the carboxylate function of ACC resonate at δ=1.42 and that the hydrogen atomstransto the carboxylate function of ACC resonate at δ=1.20. The mono-substituted cyclopropanes, cyclo-propanecarboxylic acid (CPC) and cyclopropyl-amine (CPA) were used in complementary lanthanide-reagent shift titrations along with the back titration of an ACC-Eu+++complex with DCl to further substantiate the assignment. This assignment allows for the non-destructive, nonisotopic diluting analysis of various biosynthetically derived deuterated ACC's formed from the corresponding deuteratedS-adenosyl-L-methionine.

ISSN:0038-7010    

DOI:10.1080/00387018608069307

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

ISSN:0038-7010    

DOI:10.1080/00387018608069308

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Spectra excited in a hollow cathode discharge operating at high frequency and direct currents have been studied. Samples (La2O3and Y2O3) were placed in the copper hollow cathodes and argon was a carrier gas. The excitation temperatures of Ar I, Ar II, Cu I, Y I, Y II and La II in high frequency and direct current hollow cathode discharges have been determined and compared.

ISSN:0038-7010    

DOI:10.1080/00387018608069309

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

4,6JHH-long range couplings in an estrone-type molecule are observed and demonstrated to be helpful for the complete proton chemical shift assignment.

ISSN:0038-7010    

DOI:10.1080/00387018608069310

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

We have shown in preceding papers(1–3), in a study of some specific anilinium ions such as NH+3-n(CH3)n,2NH+2and3NH+, that varying the ammonium groups, or the medium, can lead to great changes in the intensity of the secondary transition of the chromophore(1–4)because of a δ, π coupling involving the substituent(1–10)and . In the present work we should like to extend our experiments to more complex ions - since apart our own works the UV spectroscopy of the aniliniums is almost unknown - to study the sensitivity of the chromophore to long range interactions with X through space or through the bonds of the substituents(11–16).

ISSN:0038-7010    

DOI:10.1080/00387018608069311

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor