摘要:

The rare earth metal (including: La, Nd, Eu, Er, Yb and Y)-hematoporphyrin complexes have been prepared successfully using the imidazole method. Their UV-VIS, fluorescent emission and FT-IR spectra have been measured for the first time. According to the spectra of the six complexes, the correctness of their structures has been conformed, their Iø, ø4and 24−3Avhave been calculated, and their vibration peaks have been classified experientially. It has been found that ø4of the rare earth metallohematoporphyrin was greater than analogous rare earth metallohematoporphyrin, metallohematoporphyrin and hematoporphyrin. It was proved also that the rare earth metallohematoporphyrins have wide potential applications in the diagnosis and treatment of cancer. This work should provide a useful experimental foundation for further work.

ISSN:0038-7010    

DOI:10.1080/00387019108020648

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

A1H NMR spectroscopic determination of mixture of citrates and tartrates in pharmaceutical formulations was performed. The methylene AB quartet of citrate and the methine singlet of tartrate were chosen for integration, using sodium acetate as internal standard. This method does not require any operative manipulation of the material to be analysed.

ISSN:0038-7010    

DOI:10.1080/00387019108020649

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

The parameters characterizing the absorption, fluorescence and phosphorescence of 10-dodecylisoalloxazine (DIA), 10-octadecylisoalloxazine (OIA) 3-methyl-10-dodecylisoalloxazine (MDIA) embedded into polymeric matrices (polystyrene – PS, polymethacrylate methyl – PMM and poly(vinyl alcohol) – PVA) were studied. It was found that both the polarity of microenvironment and its structure influenced the changes of the spectral properties of the examined amphiflavins.

ISSN:0038-7010    

DOI:10.1080/00387019108020650

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

13C NMR chemical shift assignments were obtained for dibucaine in CDCl3and dibucaine hydrochloride in D2O solution using one-bond and long-range two-dimensional heteronuclear correlation techniques. The13C chemical shift assignments, together with the fully coupled13C spectrum, allowed the measurement of one-bond, and long-range13C1H coupling constants.

ISSN:0038-7010    

DOI:10.1080/00387019108020651

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

The third order nonlinear optical susceptibility is calculated taking into account the permanent dipole moments of the molecule and the population changes of the energy levels. It is shown that the expression of the susceptibility contains terms proportional to the difference or to the squared difference of permanent dipole moments, corresponding to different electronic states.

ISSN:0038-7010    

DOI:10.1080/00387019108020652

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

For five β-ketols of varying substitutions, analysis of the associatedvOH band, and examination of the X-ray data of analogous fragments evidence two different intramolecular association processes of weak and high energy, respectively attributed to eclipsed or bisected chelates. MM2 or semi empirical calculations do not give results quite consistent with experiment, suggesting some caution as to their use for interpreting hydrogen bonding effects in such systems.

ISSN:0038-7010    

DOI:10.1080/00387019108020653

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Aspectrophotometric study of the Palladium (II) complex of a new reagent phenyl-2-picolylketone-2-pyridylhydrazone, PPKPyH, is presented. Palladium reacts with PPKPyH in the presence of cetyltrimethylammonium bromide (CTAB) to form a red complex. The palladium complex has a maximal absorbance at pH 5.9 (containing 30% ethanol) and at 420 nm. Beer's law is obeyed up to 40 μg pd(11). The molar absorptivity is 1.9×104liters mol−1cm−1at 420 nm. The method offer advantages of simplicity, requires no extraction and selective, where 3.00 mg Pt(IV) and 0.1 mg Au(III) ions do not interfere.

ISSN:0038-7010    

DOI:10.1080/00387019108020654

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

A calculating method is presented in this paper which may be used to correct for the curvature of the calibration curve in atomic absorption spectrometry due to the non-absorbed light within the monochromator bandpass when a continuum source of radiation is used. Thus a linear absorbance to concentration relationship is obtained. Cu, Cr and Ca have been determined using this method with a D2lamp as continuum source. The results agree with those obtained by the traditional method using hollow cathode lamps. The relative differences are below 6.2%. Earlier investigations concerning the use of continuum sources in atomic absorption spectrometry (aas) have shown that in some cases there are good results1–4. However, there are two problems which are difficult to overcome in continuum source aas. First, a narrow slit must be used in order to obtain a bandpass of a width equivalent to the absorption line. However, in this case the light intensity transmitted to the monochromator and arriving to the detector is so small that the detection limits will be very poor. Of course the transmitted intensity may be increased if a wider slit is used. But in this case, the non-absorptive part on the two sides of the absorption line will also enter the monochromator and fall on the detector. As a result the sensitivity will be degraded and the calibration curve will bend towards the concentration axis. Problems such as those discussed above prevented the current use of continuum source aas. The whole field has been recently reviewd extensively4a.

ISSN:0038-7010    

DOI:10.1080/00387019108020655

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Spectroscopic studies on the reaction of iodine as π-acceptor and chloronil as π-acceptor with oxime intermediates prepared from certain pharmaceutical carbonyl compounds are reported. These compounds include Δ1,4-3-corticosteroids (prednisone, prednisolone, dexamethasone), Δ4-3-ketosteroids (progesterone, testosterone propinate, nandrolone phenpropionate), griseofulvin, carvone, and menthone. The spectroscopic techniques applied are IR, far IR spectroscopy, H1, C13NMR, mass spectra (MS), fast atom bombardment mass spectra (FABMS), electron spin resonance (ESR) and microanalysis of the reaction products. The structure elucidation studies of these complexes confirmed the charge transfer complex (CTC) formation.

ISSN:0038-7010    

DOI:10.1080/00387019108020656

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Monosaccharide osazones are utilized in the spectrophotometric determination of their parent compounds through charge transfer complexes (CTC) formation with three-electron acceptor reagents. These acceptors indlude iodine (as -π-acceptor) and chloranil (tetrachloro P-benzoquinone) & TCNE (tetracyano ethylene) as π-acceptors. The presence of two phenylhydrazone moieties in the osazone molecule imparts electron-donating properties toward electron-accepting reagents, yielding spectrophotometrically measurable complexes. However, the reaction of osazone intermediates with TCNE reagent gave tricyanovinyl derivative rather than CTC formation. The above complexes together with their corresponding intermediates were subjected to structure elucidation studies to confirm the results and conclusions obtained. These studies include IR, Raman spectra, H1, C13-NMR, MS, ESR (electron spin resonance spectra) and microanalysis.

ISSN:0038-7010    

DOI:10.1080/00387019108020657

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor