摘要:

The earlier reported matrix system methylacetate/ H2O/Ar has been reinvestigated by IR spectroscopy. The complex band pattern of the ester νc=0and the water ν3, ν1and ν2modes can be explained by the coexistence of 1:1, linear 1:2 and linear 2:1 H-bonded complexes. The study of methyl benzoate/H2O/Ar supports the proposed interpretation.

ISSN:0038-7010    

DOI:10.1080/00387018708081568

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

Vibrational analysis of the electronic absorption spectrum of ethylpyrazine observed around 320 nm is carried out. The bands are ascribed to the longest wavelength one of the four possible π* ← n systems. A “vibronic” interaction between the excited state of this system and another excited state of the molecule is observed. A π* ← π system with practically no vibrational structure is also observed and discussed.

ISSN:0038-7010    

DOI:10.1080/00387018708081569

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

Analysis of the bisignate circular dichroism spectra of bilirubin-IXα bis-propionate salts of (S)-(-)-N, N, N-trimethyl α-phenethylammonium hydroxide reveals a preference in CHC13, (CH3)2CO and CH3CN solvents for folded conformations in which the propionate groups are intramolecularly H-bonded to the opposing pyrromethenone units.

ISSN:0038-7010    

DOI:10.1080/00387018708081570

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

Extraction followed by spectrophotometry was employed to determine nitrate and nitrite in sewage sludge. Recovery of added nitrate and nitrite was complete. The procedure was suitable for the determination of nitrate nitrogen and nitrite nitrogen in this matrix.

ISSN:0038-7010    

DOI:10.1080/00387018708081571

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

Infrared spectra of codeposited ethyl benzoate with excess titanium tetrachloride at 80 K revealed a novel 2:1 complex, where the inorganic entity is proposed to be a dimeric, triple bridged titanium tetrachloride unit. The ester is complexed to one of the octahedral titanium units through the carbonyl group. Compared to the 2:2 complex there are νc=o'να-C-Oand νTi-Oshifts of -40/-47, +4/+24 and +16/17 cm−1, depending on which of the18O-carbonyl or d5-ethyl isotopic congeners is considered.

ISSN:0038-7010    

DOI:10.1080/00387018708081572

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

A single stage impaction system connected to an electrothermal atomization atomic absorption spectrometer will allow a direct and near real time determination of mercury in the laboratory atmosphere to be detected. Practical concentrations of low ng m−3 can be detected, with good precision and linearity of calibration curve. The system detected m−3 levels of mercury directly and on a near real time in the vicinity of a polarography instrument.

ISSN:0038-7010    

DOI:10.1080/00387018708081573

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

There are two possible configurations for H2O, linear(D∞h) or bent(C2v). For a C2v′, the three bands ν1′ν2and ν3should appear in both Raman and infrared. For a D∞h. however, the ν1, band should appear in only Raman and the ν2and ν3bands, in only infrared, that is, a principle of mutual exclusion of Raman and infrared should hold. The present author concludes that H2X and D2X(X=O, S, Se, Te) have a linear D∞h. structure, since the obtained spectra show mutual exclusion of Raman and infrared.

ISSN:0038-7010    

DOI:10.1080/00387018708081574

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

The specific interaction between parafluorophenol and alkylbenzenes in n-hexane has been studied using infrared spectrometry. The absorption spectra of different donor-acceptor couples exhibit bands in the region 3600–3500 cm−1which are characteristic for the formation of hydrogen bonded complexes OH…eπ. The observed frequency shifts are between 67 and 92 cm−1, and the values of the complexation constant range from 0.41 to 1.51 dm3mol−1. The values of the free enthalpy of interaction -ΔG are situated between -2.22 and+1.05 kJ.mol−1, while the affinity ratio varies from 3.08 to57.98.

ISSN:0038-7010    

DOI:10.1080/00387018708081575

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

An optogalvanic signal enhancement was obtained in a magnetic field applied on a hollow cathode discharge-detector. In this magnetic field a mutual correlation was observed between optogalvanic signal behaviour, discharge current change and lower level population of the transition corresponding to the 632,8 nm laser irradiation spectral line.

ISSN:0038-7010    

DOI:10.1080/00387018708081576

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

A new proton magnetic resonance (PMR) method for the quantitative determination of 2,5-Diaziridinyl-3,6-bis (carboethoxyamino)-1,4-benzoquinone and its acid decomposition products in dimethylsulfoxide-d6, and at 35 ± l° is described. The PMR spectrum of 2,5-Diaziridinyl-3,6-bis (carboethoxyamino) -1,4-benzoquinone shows singlet system at Δ 2.2 due to the protons of the two aziridine rings. The integral ratio of this signal to that of the methyl protons signal at Δ 1.2 and the methalene protons signal at Δ 4.05 is 4:3:2 in the intact molecule. The acid catalayzed decomposition results in disturbance of this ratio since the two aziridine rings are opened consecutively and a new multiplet signal appear at Δ 3.4–3.7 due to the ethelene group protons of the hydroxyethylamino group formed upon decomposition of aziridine moiety. Comparing the integral of the signal at Δ 1.2, 2.2, 3.4–3.7 and 4.03 to that of the sharp singlet at Δ 6.83 of 1,4 p-benzoquinone which is used as internal standard constitute the basis of the method.

ISSN:0038-7010    

DOI:10.1080/00387018708081577

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor