摘要:

The infrared spectra of a series of crystalline sulfate-apatites of the type AI3MII2(SO4)3X are presented and discussed. It is demonstrated that the sulfate groups are not greatly distorted in these compounds.

ISSN:0038-7010    

DOI:10.1080/00387017908063473

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

The complexity of the carbonyl stretching region has been the subject of several investigations and interpreted by rotational isomerism or Fermi resonance1-6as observed by Parellada et al7and Woldbaek et al8, the infrared spectrum of succinimide is characterized by a complicated pattern in theVC ˭ Orange but so far, no systematic study of this spectral behaviour has been reported. This work presents a solvent variation study of theVC ˭ Ovibration of succinimide and a tentative assignment of the Fermi resonance doublet.

ISSN:0038-7010    

DOI:10.1080/00387017908063474

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

In a previous publication2, we reported the binding constants for the lanthanide shift reagent Yb (thd)3in equilibrium with a series of substituted aniline donors. These binding constants were measured by Infrared spectroscopy utilising the changes in amino stretching frequency absorbance at equimolar there is much less hindrance to lanthanide binding and K (93.1) is greatly increased.

ISSN:0038-7010    

DOI:10.1080/00387017908063475

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

The infrared spectra of sixteen metal complexes comprising the ligands quinoline, pyridine, aniline and their fully-deuterated analogues have been examined in order to determine the ratioDv/Hvfor bands assigned to the C-H and ring modes of the heterocyclic or aromatic ring. With very few exceptions,Dv/Hvfalls within the ranges 0.68 to 0.85 for C-H vibrations and 0.85 to 1.00 for ring modes. The ranges are narrower for complexes of a specific amine. The potential usefulness of the results is discussed.

ISSN:0038-7010    

DOI:10.1080/00387017908063476

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

Several authors have described the interaction of ion pairs such as alkylammonium halides with proton donor molecules in aprotic organic solvents sing NMR1,2, mid-infrared2-6or electronic spectroscopy7,8but few far-infrared studies of ion pairmolecule association have been reported in the literature. However, the interaction between alkylammonium halides and benzoic acid9or phenol10has been studied by the far infrared technique and it has been shown that in solvents of low dielectric constant, both cation-anion and anion-molecule stretching vibrations can be simultaneously observed.

ISSN:0038-7010    

DOI:10.1080/00387017908063477

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

The13C n. m. r. spectra of benzothiophene and dibenzothiophene, not mentioned so far in literature are presented. The presence of six signals in the13C {1H } n, m.r. dibenzothiophene spectrum confirms the symmetry of its electronic structure and magnetic effects and indicates the molecule to be flat. In the case of dibenzothiophene the carbons which are common to both the thiophene and benzene rings show somewhat lower chemical shifts if compared with benzothiophene.

ISSN:0038-7010    

DOI:10.1080/00387017908063478

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

A rapid and accurate PMR procedure is described for the quantitation of xanthotoxin (8-methoxypsoralen) as a drug entity and in tablet dosage form. A standard deviation of 2.8% was obtained on 10 standard mixtures. The PMR spectrum, in addition, provides a very specific method for identification of xanthotoxin and detection of its biologically inactive isomer, bergapten (5-methoxypsoralen).

ISSN:0038-7010    

DOI:10.1080/00387017908063479

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

The IR and Raman spectra of N-C1-phthal imide were recorded for polycrystalline samples. The fundamental frequencies were tentatively assigned on the basis of a C2vmolecular symmetry by comparison with those of phthalic anhydride and phthalimides. The band shifts from the related compounds are discussed in terms of the mechanical coupling among the fundamental vibrations and of the electronic resonance structures. The N-C1 vibrations are compared with those of N-C1-maleimide and N-C1-succinimide.

ISSN:0038-7010    

DOI:10.1080/00387017908063480

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

The IR spectrum of pyromellitic diimide, HN(CO)2C6H2(CO)2NH, has been measured for polycrystalline sample. The observed bands have been assigned to the IR active fundamentals and combinations on the basis of a D2hmolecular symmetry by comparison with those of pyromellitic dianhydride. Band shifts from dianhydride to diimide were observed for the 0˭C-X-C˭O fundamentals and the N-H modes have been assigned by comparison with those reported for phthalimides.

ISSN:0038-7010    

DOI:10.1080/00387017908063481

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

Combination vibrations of neighbouring H-bonded molecules show a characteristic absorption band. This band appears in the spectra if H-bonds are formed and vanishes when the H-bonds are broken. Different observations allow the conclusion that the combinationvOH+vODin spectra of liquid HOD (in D2O) may be assigned to a combination vibration (vOH+vOD) 2molof two neighbouring molecules (HOD and D2O). The intensity of thisvOD) 2molband was investigated at different temperatures. It results an estimation of the van't Hoff enthalpy change of H-bond formation in liquid water ΔHo(OH O) = -15.4 ± 1.0 kJ/mole (= -3. 7 ± 0. 2 kcal/mole).

ISSN:0038-7010    

DOI:10.1080/00387017908063482

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor