摘要:

The reactions of π-electron acceptors such as 1-chloro-2,4,6-trinitrobenzene (picryl chloride), 7,7′,8,8′-tetracyanoquino-dimethane (TCNQ), tetrachloro-p-benzoquinone (chloranil) and tetra-cyanoethylene (TCNE) with the cyclic polyamine base 1,4,8,11-tetraazacyclotetradecane (TACTD) have been investigated in CHCl3solvent. The data indicate the formation of the CT-complexes with the general formula [(TACTD) (acceptor)2]. The 1: 2 stoichiometry of the (TACTD)-acceptor was based on elemental analysis and infrared spectra of the solid CT-complexes along with the photometric titration curves for the reactions in CHCl3. The formation constants (K) for the CT-complexes are shown to be strongly dependent on the type and structure of the acceptor.

ISSN:0038-7010    

DOI:10.1080/00387019708006710

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

Mid-infrared spectra in the range 400–1800 cm−1of methanol samples in diamond anvil cells at ambient temperature and pressures up to 11 GPa are reported. The freezing pressure is confirmed to be 3.6 GPa, and the spectra of the resulting metastable glass are very similar to those of the liquid. When maintained at high pressure, the glass spontaneously transforms to an ordered crystalline phase which is stable over the range 3.6 to 11 GPa. Small changes in peak wavenumbers for 14 internal modes as a function of pressure are observed, indicating that distortion of the molecules is minimal. A slight decrease for the C-O-H bending mode is attributed to charge transfer from the molecular 0-H bond to the strengthening intermolecular hydrogen bond.

ISSN:0038-7010    

DOI:10.1080/00387019708006711

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

Variations in the fluorescence in the intensities of anthracene derivatives under a magnetic field were investigated in the presence of a dilute magnetic fluid. When excitation was carried out with light that was polarized parallel to the magnetic field, the intensity of the fluorescence that was polarized paralell to the magnetic field decreased by about 10%. Although the fluorescence intensities of most of the anthracene derivatives showed a similar decrease in magnitude, that of 9,10-dimethylanthracene showed a large decrease. On the other hand, fluorescence increased when excitation and fluorescence were perpendicular to the magnetic field. The obtained phenomena can be explaned by the formation of anisotropic assembly of magnetic fluid particles in the solution.

ISSN:0038-7010    

DOI:10.1080/00387019708006712

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

Aliquots of waste water from power stations were analyzed by a special procedure in order to put in evidence the presence of renex, a nonionic detergent. The investigations were performed spectroscopically by FTIR technique. Qualitative and quantitative features of the procedure were established as specific peaks, detection limit and method sensibility. The validity of Lambert-Beer law was checked. Taking into account the selectivity of the method it results the necessity of separating renex from nitrogenous bases in the analyzed water.

ISSN:0038-7010    

DOI:10.1080/00387019708006713

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

Some emission properties of Alternating Current Electroluminescencent (AC EL) structures containing thin chalcogenide films of the systemsAs-SorGe-Sb-Sare investigated by means of optogalvanic effect. The optogalvanic characteristics of red emitting structures at different conditions of their excitation are presented. Conclusions about the behaviour of the emission are drawn and some possibilities of the proposed method for the examination of the AC EL structures are analysed.

ISSN:0038-7010    

DOI:10.1080/00387019708006714

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

Series of Co-Al and Co-Cu-Al hydrotalcites were synthesized, thermally activated and characterized. The correlation between the hydrotalcite composition and their IR spectra were discussed along with the results of X-ray diffraction analyses. The specific surface areas of hydrotalcites and their catalytic activities for nitrous oxide decomposition upon calcination were studied. As Co was partially replaced by Cu. the catalytic activity was improved by 10% under the same reaction conditions (Co/Cu/Al = 2.7/0.3/1). A spinel CuxCo3-xO4was formed in calcined hydrotalcites.

ISSN:0038-7010    

DOI:10.1080/00387019708006715

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

Photoacoustic spectra of some sketch pen and fountain pen inks of different makes and colours, and a correcting fluid (used in cyclostyling) have been recorded in the spectral range of 350 to 750 nm, at room temperature of 25 C. The spectra have been analyzed in order to compare the nature of different inks. For this study, an open photoacoustic cell with PZT transducer having obvious advantages over gas phase microphone detection system, has been used.

ISSN:0038-7010    

DOI:10.1080/00387019708006716

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

The photoacoustic (PA) spectrum of naphthalene cation in boric acid glass, in the region 250–400 nm is reported for the first tune and compared with its optical absorption spectrum. The energy levels for the ions are calculated using open shell Wasilewski method with limited configuration interaction and used to interpret the observed PA spectrum.

ISSN:0038-7010    

DOI:10.1080/00387019708006717

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

The paramagnetic contributions to the spin-lattice relaxation rates of biotin13C nuclei, induced by the presence in the water/DMSO solution of the TEMPOL nitroxide, have been analysed in the interaction with avidin. The paramagnetic relaxation data, obtained at different temperatures, indicate that the average solvent/spin-label exposure of biotin carbons is consistent with the conformational features previously observed for the complex in the crystal. The analysis of the paramagnetic perturbation profiles, derived from13C spin lattice relaxation measurements, seems to be highly informative of the sterical aspects of interaction processes of large biopolymers with their ligands.

ISSN:0038-7010    

DOI:10.1080/00387019708006718

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor