摘要:

Summary - A rapid, accurate, precise and reproducible1H-NMR assay and a direct UV one of ornidazole-bulk drug and tablet dosage forms are presented. The recoveries (Mean and S. D.%) by the1H-NMR method were within 1% of those by the UV-method. The1H-NMR method is based on the integration of the 2-methyl protons of ornidazole relative to that of the methyl protons of acetanilide (internal standard). The UV-method is based on the conjugated chromophoric nitroimidazole nucleus of ornidazole molecule. Moreover, very satisfactory mean recoveries for the bulk drug, added to its formulations, have been established.

ISSN:0038-7010    

DOI:10.1080/00387018908053865

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The proton NMR spectra of the antileukemic agent glyoxal bis(amidinohydrazone) and of nine alkyl- and dialkylglyoxal analogs thereof, many of which are novel compounds, are reported. Measurements were carried out using both the free bases (in D2O and dimethyl sulfoxide-d6) and their divalent salts (in D2O). Dioxan was a suitable internal standard, while DSS caused extensive precipitation. Most spectra were first-order or nearly so, and the resonances of the various protons could be rigorously

ISSN:0038-7010    

DOI:10.1080/00387018908053866

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The first survey of the carbon-13 NMR spectroscopy of the bis(amidinohydrazones) [‘bis(guanylhydrazones)’] of various glyoxals is reported. The compounds studied included the free base and the dihydrochloride of the investigational antileukemic drug methylglyoxal bis(amidinohydrazone) (MGBG) and the dihydrochloride of the parent compound glyoxal bis(amidinohydrazone), as well as the free bases of seven alkyl- and dialkylglyoxal analogs of these compounds. Spectra were assigned with the aid of off-resonance proton noise decoupled carbon-13 measurements. The results obtained strongly suggest that each of the compounds studied consisted of one of the three or four possible geometrical isomers only, or that (less probably) the isomerization of the compounds is rapid on the NMR time scale. Thus, the results are in line with previous proton NMR and X-ray crystallographic observations, and support the theory that the classical syntheses of the compounds tend to yield

ISSN:0038-7010    

DOI:10.1080/00387018908053867

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Using the force fields due to Nishimura et al.[1] and to Harsanyi et al.[2], dipole moment derivatives (DMD's) and their orientations have been computed byab initiotechniques. The values so computed using the above two force fields are surprisingly close to each other. The DMD's corresponding to the C = O stretching (s) and CN s are found to be among the most significant. The DMD values of C2= O s and C4= O s are found to be comparable in value, both of them thus expected to contribute to C = O s ir band intensities. The DMD's of NH in-plane bending (ipb) modes are found to be surprisingly small, thus explaining the observed absence of splittings due to the corresponding transition dipole- transition dipole coupling (TDC) interactions. The DMD values obtained here are shown to be crucial in deciding which of the observed bands in solid state or condensed phase samples could be due to Fermi resonance and/or overtone and/or combination bands. They could also be used effectively in studying relative ir intensities of samples in condensed phases.

ISSN:0038-7010    

DOI:10.1080/00387018908053868

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The reactivity of the neutral Cp2Ti(AsF6)2(Cp = C5H5) and the ionic Cp2Ti(CH3CN)32+(AsF6−)2toward water (D2O) has been investigated and elucidated by1H and19F NMR spectroscopy. Both compounds dissociate into ionic pairs. Due to the pH value (pH < 3.5, saturated solution) the titanocene group (Cp2Ti) remains intact (1H NMR). Also t h e AsF−6anion seems to be stable at the low pH value (19F NMR), aftera small amount (14–20%, relating t o F) has hydrolysed yielding DF, which was identified by 19F NMR spectroscopy. These results are important because titanocene and especially the hydrophilic cationic titanocene derivatives are of high interest in terms of their strong antiproliferative activity.

ISSN:0038-7010    

DOI:10.1080/00387018908053869

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

By the aid of 2D NMR spectra and T1(C-13) values of cellobiose in DMSO it is possible to obtain valuable information on spectral assignments, on the over-all structure of cellobiose and indirectly on the H-bonding with the DMSO solvent molecules.

ISSN:0038-7010    

DOI:10.1080/00387018908053870

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Buildup factors BNfor the number of gamma-rays in C, H2O, Al, Cu and Pb absorbers have been measured and the variation of BNwith the atomic number Z and the thickness of the absorber were investigated. Linear absorption coefficient and the buildup factor of a soil sample were measured and the effective-Z (Zeff) of the sample was estimated from BNversus Z curve. The soil sample was also analyzed for its constituents to evaluate its absorption coefficient and the Zeffwas re-determined. The results obtained using these two methods were compared and they were found to be in good agreement.

ISSN:0038-7010    

DOI:10.1080/00387018908053871

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The semiempirical MINDO/3 CI method was employed for studies of the electronical spectra of the diatomic hydrides. It was shown that this approach was very satisfactory for study of the electronical structure and for qualitative estimation of the features in the spectra. The intensity of the spin-forbidden transition in diatomic species were calculated on the basis of the MINDO/3 CI method and spin-orbit coupling (SOC) has been taken into account as a perturbation. Fine structure constant (SOC constant A for3states, spin-rotation and zero-field splitting for3σ−state) were obtained and verified by experiment where possible.

ISSN:0038-7010    

DOI:10.1080/00387018908053872

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

ISSN:0038-7010    

DOI:10.1080/00387018908053873

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

This is a scanned image of the original Editorial Board page(s) for this issue.

ISSN:0038-7010    

DOI:10.1080/00387018908053864

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor