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Elizabeth M. Holt Balawant S. Joshi Dilip H. Gawad S. William Pelletier 《Journal of chemical crystallography》1990,20(3):261-264
The crystal and molecular structure of 1-ethyl-4-methoxy-9H-pyrido[3,4b]indole (crenatine) carbonate C14H14N2O·H2CO3, (MS, m/z 226)M
R
288.3, a-carboline alkaloid, has been determined from X-ray diffraction data. The compound crystallizes in the space group Pbca with cell parameters:a=11.616(4),b=18.450(8),c=12.992(5)Å,V=2784(2)Å3,Z=8,D
calc=1.375 g cm–3, (MoK)=0.71069Å,(Mo K)=0.94 cm–1,F(000)=1216,R/R
w
=8.2/10.3% for 1099 reflections. The ring system of the-carboline nucleus is planar. The title compound shows a two center hydrogen bond between the indole N-H group and the oxygen atom of a carbonate group. The structure does not display hydrogen bonding between-carboline groups but rather a bonding network involving the carbonate group. 相似文献
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ALBERT VAN DE VORST 《Photochemistry and photobiology》1971,13(4):321-336
Abstract— –The photosensitization of amino acids by proflavine is studied using the technique of electron spin resonance spectroscopy. The analysis of the line shape as a function of the incident microwave power (both in the presence and absence of oxygen) and the dependence of the numbers of free radicals on the intensity of the incident light allow one to suggest that two types of radicals are formed. One is formed by a biphotonic process, the nature of the radicals being the same as in the case of ionising radiation, while the other is probably the RO2 radical formed as a result of photodynamic action. 相似文献
5.
C. Cerjan R. Hedges C. Holt W. P. Reinhardt K. Scheibner J. J. Wendoloski 《International journal of quantum chemistry》1978,14(4):393-418
The theories of the dilatation, r → r eiθ, and translation, x → x + iq, transformations as related to the Stark problem are reviewed, and new results obtained. Results for the hydrogen atom n = 1 and n = 2 levels and the 1P0, 2s2p H? shape resonance in dc fields are presented, and the extension to the ac Stark effect made. Spectral estimates are made using the technique of the numerical range and via discussion of several model problems, using both coordinate rotation and coordinate translation. 相似文献
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Nineteen sulphonated 2-hydroxybenzophenones and three sulphonated 2,2′-dihydroxybenzophenones have been prepared and compared with a commercially available member of each class of uv absorber as photo-protective agents for wool. Treated fabrics were exposed to Philips ML G/74 lamps and the extent of photo-tendering was assessed by measuring breaking loads and tear strengths. In general, 2-hydroxybenzophenones with 3-alkyl substituents provide better protection against photo-tendering than absorbers lacking 3-alkyl substituents. 2,2′-Dihydroxybenzophenones are more effective than 2-hydroxybenzophenones.
On the basis of effectiveness and ease of synthesis, 2,2′-dihydroxy-4,4′-bis-w-sulphobutyloxybenzophenone (VIIb) shows most promise as a photo-protective agent. At the 5% level of application it trebles the lifetime of wool fabric during exposure to sunlight through window glass. It also retards the photo-tendering and fading of wool fabrics containing either a red or a blue milling acid dye. 相似文献
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The orientational data of four rigid solutes dissolved in the nematic solvents ZLI1132, EBBA and in a 55wt% ZLI1132 + EBBA mixture have been obtained from proton NMR spectra at different temperatures and used to find a relationship between the solute order in the two nematics and in their mixture. A crossed comparison of the data shows that a simple linear relation, where the normalized weights of the combination are coincident with the molar fractions of ZLI1132 and EBBA in the mixture, gives excellent agreement independently of the solutes and temperatures. Consideration is given to the possibility of a generalization of the results to any mixture of two nematics. 相似文献
10.
The fine and hyperfine structure of 14N2+ has been observed in 31 rotational lines of the (0, 1) band of the B2Σu+-X2Σg+ system using the method of Doppler-tuned laser-induced fluorescence on a molecular ion beam. The spin-rotation constants (γ′, γ″, γ′J) are in good agreement with other experiments in which the hyperfine structure was not resolved. The Fermi-contact (b′F, b″F) and dipolar (t′, t″) hyperfine coupling constants are in reasonably good agreement with values calculated from ab initio wavefunctions. The least-squares experimental values in MHz are γ″ = 279.1(6), γ′ = 726.4(6), γ′J = ?0.0460(2), b″F = 105(4), b′F = 708(3), t″ = 49(6), and t′ = 26(5). 相似文献