摘要:

In this study, we attempted to clarify the coordination state and the distribution of copper (II) ions in the CuThO compounds prepared by coprecipitation, by using several physico-chemical techniques in particular, X-Ray Photoelectron Spectroscopy (XPS).

ISSN:0038-7010    

DOI:10.1080/00387019008054499

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Planar Pd(LH)2complexes (LH2= H2N C S C S N H2, CH3HNCSCSNHCH3) form mixed polymeric complexes with Ni(II), Cu(II), Zn(II) and Cd(II) in alcalic media, where the planar Pd(LH)2complexes act as tetradentates with N-coordination. The electronic spectra and thermal behaviour are discussed, a thorough investigation of the i.r. spectra is presented and special attention has been given to the H/D, CH3/CD3and58Ni/62Ni,63Cu/65Cu and64Zn/68Zn isotopic shifts.

ISSN:0038-7010    

DOI:10.1080/00387019008054500

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Rapid direct and induced difference spectrophotometric methods for determination of pyrithioxin in single dosage forms (tablets and syrups) are reported. The direct methods depend upon measurement of the absorbance of pyrithioxin in different media at λmaxi-e at 296 nm in 0.1 M hydrochloric acid, at 328 nm in citric acid-phosphate buffer of pH 7 and at 314 nm in 0.1 M sodium hydroxide. The mean percentage recovery of the authentic samples were 100.55±0.43, 101.21±0.58 and 100.29±0.64 respectively (P=0.05). The absorbance difference methods are based upon either measurement of the difference between the acid and the alkaline solutions i-e. Δ A (Alk-Acid) at 318 nm with an accuracy of 100.72±0.88 or the absorbance difference between the acid and neutral solutions i-e Δ A (pH 7-acid) at 328 nm with an accuracy of 100.31±0.68.

ISSN:0038-7010    

DOI:10.1080/00387019008054501

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

A simple spring model for molecular vibrations, which uses Cartesian co-ordinates for both longitudinal and transverse displacements, is applied to centrosymmetric linear quadratomic molecules, such as cyanogen and acetylene and its halogenated derivatives. Analytical expressions for the three stretching and two bending mode frequencies are obtained in terms of five independent force constants. By substitution of Raman and infrared frequencies, values of these force constants are obtained and briefly discussed. The validity of the model is confirmed by the satisfactory agreement between calculated and observed frequencies of isotopic species.

ISSN:0038-7010    

DOI:10.1080/00387019008054502

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

The excitation temperatures of nonmetal atoms and the OH molecule temperatures have been measured in argon MIP, operating under atmospheric pressure at different experimental conditions. Atoms of Ar I, P I and H have been used as thermometric species. The rotational and vibrational temperatures have been obtained from the OH A2Σ+- X2⊓ band spectra. TheSR21ratational lines have been used for the first time for the temperature measurements. The energy distributions observed here are discussed.

ISSN:0038-7010    

DOI:10.1080/00387019008054503

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

The present study was conducted to investigate the molecular absorption by AlBr in a carbon rod furnace for determination of bromine, by using the arsenic atomic line at 279.028 nm emitted from an As- hollow cathode lamp. A deuterium lamp was used for the simultaneous background correction. The interference caused by the other halogenides and some cations was also examined. The method was applied to determine bromine in organic matrice.

ISSN:0038-7010    

DOI:10.1080/00387019008054504

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Vibrational spectra of 2,2′-pyridil and 2,2′-pyridil-18O in the solid state and in solutions have been measured in the Raman (4000–50 cm−1) and infrared (4000–100 cm−1). The assignment of the bands observed is performed using the group vibrational concept and isotopic shifts data of the normal modes. The presence of synand anti-phase vibrations of both pyridyl rings is discussed. The results are compared to the corresponding data for some similar molecules.

ISSN:0038-7010    

DOI:10.1080/00387019008054505

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

The conformation of 2,4-dinitrophenyl 4′-substituted phenyl sulfides, sulfoxides and sulfones are explored.1H-NMR and IR data are represented. The results obtained indicate that the chemical shift of the ortho proton (H-6) in the dinitro ring in sulfides under consideration is dependent on the nature of substituents present in the 4′-position, affording a further evidence for the adoption of a skew conformation. Different conformations are assigned to sulfoxides and sulfones. The chemical shift for H-6 in the nitro ring nicely correlates with σPHammett in sulfides. Correlation for μC-S, and μSO2with Hammett σ values are poor.

ISSN:0038-7010    

DOI:10.1080/00387019008054506

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

ISSN:0038-7010    

DOI:10.1080/00387019008054498

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor