摘要:

Solid Cu(2-Benzoylpyridine)2(NO3)2has been studied by UV-Vis, IR, and EPR (X-band, Q-band) techniques. Monoclinic crystal symmetry was determined with two molecules per unit cell. Copper (II) is coordinated by two benzoylpyridine ligands and a single NO3group in the chromophore CuN2O3of distorted trigonal bypiramidal stereochemistry. Exchange coupling values were determined from EPR spectra as |J| = 0.0026(2) cm−1between magnetically nonequivalent copper (II) sites, and |J| < O.3 cm−1between equivalent sites.

ISSN:0038-7010    

DOI:10.1080/00387018908053885

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

13C and31P NMR parameters were obtained for phosphomycin in water solution. The pH dependence of chemical shifts was used to calculate the pK of the second deprotonation process (pK2= 6.4). The pH dependence of13C‒31P and13P‒31H coupling constant was pointing to a change in dihedral angles and hence in the geometry of phosphomycin during deprotonation. The pH dependences of31P spin-lattice relaxation rates and13P‒{1H} NOEs were interpreted in terms of relative weigth of the 31P-1H dipolar interaction in determining the relaxation mechanism.

ISSN:0038-7010    

DOI:10.1080/00387018908053886

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Several isomers N1and N2substituted indazole-3-carboxylic acids were prepared and their data obtained from current analysis, mp, IR, NMR, TLC were reported. Utilizing these values, it is very difficult to determine to which of the two isomeric structures a product corresponds. On the contrary with the use of UV derivative spectrophotometry it is simple to establish if a product alone, somehow substituted, corresponds to one or to other structure.

ISSN:0038-7010    

DOI:10.1080/00387018908053887

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Infrared and Raman spectra of benzo-15-crown-5 derivatives were obtained in order to investigate the crown ring conformation. Following the establishment of the conformation sensitive bands the most probable local conformers for the various O-CH2-CH2−O and CH2-CH2−O-CH2-CH2units have been suggested.

ISSN:0038-7010    

DOI:10.1080/00387018908053888

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

From variable temperature NMR studies of trans1and cis24-cyanocyclohexanols d4−2, 2, 6, 6, the conformational enthalpy values for CN (-0.84 kJ mol−1) and OH (-3.03 kJ mol−1) substituents are obtained together with the activation free enthalpy differences at the coalescence temperatures (ΔG≠1= 47.74 and ΔG≠2= 47.65 kJ mol−1). The structures obtained by the studies of 1r, 3c, 4t3and 1r, 3c, 4c43-tert-butyl 4-cyanocyclohexanols d4−2, 2, 6, 6 agrees with a distorted chair conformation due to the tert-butyl cyano gauche interaction.

ISSN:0038-7010    

DOI:10.1080/00387018908053889

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The simultaneous action of 355-nm and 1064-nm laser lights with 10-ns duration gave substantially larger photo-current signals than those when the 355-nm light acted alone for various aromatic molecules in n-heptane. The photocurrent signal tended to be larger for a larger molar absorptivity of a molecule. The enhancement of the photocurrent signal induced by the additional action of the 1064-nm light was correlated with the excess excitation energy as well as the 1064-nm pulse energy.

ISSN:0038-7010    

DOI:10.1080/00387018908053890

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The assignment of a band near 1600 cm−1in IR spectra of carbons has been controversial for four decades. However, many different carbons have been studied: effectively, a single band assignment was sought for an absorption appearing with three different classes of carbon. As these differ in over-all structure, not one but three explanations are needed. These are discussed. However, undue emphasis has been placed on a single absorption; attention should also be paid to other absorptions accompanying the 1600 cm−1band.

ISSN:0038-7010    

DOI:10.1080/00387018908053891

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The feasibility of determining uranium in natural waters for uranium exploration using dibenzoil methane (DBM) by the adsorption of U(VI) on ferric hydroxide, was investigated. The yields of coprecipitation were determined by a Scintrex UA-3 laser fluorimetric uranium analyser using standard uranium solutions. After dissolving the coprecipitate, uranium was selectively separated by carbonate precipitation and determined with DBM. Fe(OH)3- DBM method was controlled using both standard solutions and uranium analyser measurements of some natural water samples taken from Northern Ege Region where detailed radiometric investigation has been going on. The advantage of this method

ISSN:0038-7010    

DOI:10.1080/00387018908053892

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Long chain mono-unsaturated alcohol acetates are important in practice as insect sex pheromones of lepidoptera. We have studied the relationship between the vibrational spectra of this kind of compounds and their structures(1). The compounds are similar in vibrational spectra even though they have differerces in both the length of chain and the position of double bond. The normal coordinate analysis of these compounds have not been reported in the literature yet.

ISSN:0038-7010    

DOI:10.1080/00387018908053893

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The hydrogen bonded complexes between carbonyl bases and hydroxylic derivatives have been extensively studied by infrared spectrometry; by comparison very little Raman data have been reported in the literature. Some qualitative measurements on thevC=Oband of acetone dissolved in water-tetrachloride mixtures have been performed by Singurel1. Quantitative data on the absolute Raman intensity have been obtained for complexes involving cyclohexanone2, acetone, acetophenone3and methylacetate4. For these systems, hydrogen bond formation brings about a moderate intensity enhancement of thevC=Oband. In this work the Raman intensity of thevC=Oband of ethylformate (EtFo) complexed with phenol derivatives is investigated.

ISSN:0038-7010    

DOI:10.1080/00387018908053894

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor