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111.
Fenesan I Popescu R Supuran CT Nicoara S Culea M Palibroda N Moldovan Z Cozar O 《Rapid communications in mass spectrometry : RCM》2001,15(9):721-729
This work discusses the synthesis and the fragmentation patterns for 2-(p-acetylaminosulfonamido)-2-thiono-(5,5-dimethyl-1,3,2-dioxaphosphorinane)(1) and for the p-acetylaminosulfonylamides of O,O-diethylthiophosphoric acid (2), O,O-diphenylthiophosphoric acid (3), dimethylaminocyclohexylthiophosphoric acid (4), and diethylaminophenylthiophosphoric acid (5). A thionamidic-thiolimidic structure was attributed to compounds 1-5, consistent with their IR and NMR spectra. EI mass spectra at 70 eV, high resolution (HR) mass measurements and metastable ion spectra were used to elucidate the fragmentation processes and to determine the kinetic energy release values associated with the metastable ion dissociations. HR accurate mass measurements were used to confirm the compositions of the more abundant ions. 相似文献
112.
Pyrolysis of α-phenylacetanilide resulted in migration of the benzyl group to the o and p positions of the aniline nucleus and formation of CO, NH3, toluene benzaldehyde, dibenzyl, trans stilbene, aniline, 9 phenylacridine and 2,3 diphenyl-indole. With o-toluidine as a solvent the previous products were accompanied by 2,3 diphenyl-7-methylindole and 4 amino 3 methyl diphenylmethane. With isoqumoline 1 benzyl isoquinoline and 1,1' bi-isoquinolyl were also obtained.It is concluded that the pyrolysis of phenylacetanilide depends on the homolytic fission of the amide C-N bond into anilino and phenylacetyl free radicals followed by the interaction of the primary and secondary formed radicals with the rearrangement products and solvent nuclei. 相似文献
113.
S. Z. Taits O. A. Kalinovskii V. S. Bogdanov Y. L. Gol'dfarb 《Chemistry of Heterocyclic Compounds》1970,6(11):1367-1372
A mixture of isomers corresponding to closing of the ring at the 3 and 4 positions of the thiophene ring is formed during intramolecular acylation of 12-(5-methyl-2-thienyl)-lauryl chloride in a homogeneous medium; the reaction proceeds primarily to favor the formation of the isomer with the larger ring (80%). A method for the synthesis of macrocyclic -alkylcycloalkanones by reductive desulfurization of the corresponding bicyclic ketones, which contain thiophene rings, was developed.See Izv. Akad. Nauk SSSR, Ser. Khim., 2228 (1970) for Communication XI.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1467–1472, November, 1970. 相似文献
114.
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116.
Y.A DemchenkoA Razina Z SedlákovaA Sikora J BaldrianM Ilavský 《European Polymer Journal》2002,38(12):2333-2341
Thermotropic polyesters based on 4,4′-alkane-1-ω-diylbis(4-hydroxybenzoic acid) and 4,4′-(pentane-1,5-diyloxy)dibenzoic acid were studied by dynamic mechanical spectroscopy, X-ray scattering, differential scanning calorimetry and polarizing microscopy. The effect of structure changes in the mesogenic group as well as in the flexible spacer, in particular the incorporation of Cl atoms into the mesogen, introduction of ether oxygen into spacer and the number of CH2 groups in spacer was investigated. More complex mechanical and thermal behaviour was found on second heating scan than on first cooling of the isotropic melt; higher values of mechanical functions were observed in the isotropic state than in the nematic state of melts. While an even number of CH2 groups and the presence of ether oxygen in spacer shifts the transition temperatures to higher values, the incorporation of Cl atoms into the mesogen leads to disappearance of ordered structure and the polymers behave as amorphous materials. 相似文献
117.
C.L. Liu X.Y. Wang Z.M. Wang S.S. Li C.T. Xin H.F. Wang B. Li L. Jiang 《Journal of Radioanalytical and Nuclear Chemistry》2001,250(3):587-591
The migration of 99Tc in a weak loess aquifer was investigated in-situ with undisturbed aquifer medium columns. The columns were obtained horizontally at a depth of 3236 m in an Underground Research Facility (URF). Quartz containing 3H (HTO) and 99Tc (in the form of 99TcO4
-) was introduced into one end of the columns and the columns were covered tightly. Aquifer water was introduced into the columns directly from an experimental shaft in the UFR. Effluents from the columns were collected and the activity of 3H and 99Tc were determined with a liquid scintillation analyzer. The breakthrough curves of 3H and 99Tc indicate that 99Tc migrates a little faster than that 3H does in the aquifer. 相似文献
118.
A. Dávid G. Horváth Z. Mészáros T. Meisel Z. Halmos 《Journal of Thermal Analysis and Calorimetry》1974,6(1-2):59-66
The thermal behaviour of tetrahydroperparine (THP) and its derivatives with various acids has been investigated. The acid is liberated from the formate derivative basically in two steps, while the other aliphatic acids are released quantitatively before the thermal decomposition of the THP molecule. The thermoanalytical curves, electrical conductivity data measured in the molten phase, and infrared spectra prove that while part of the formic acid is hydrogen-bonded the other part is bound ionically in the molecule. It may be assumed that the marked biological activity of the compound can be explained by this difference in the nature of the bonds. 相似文献
119.
A new method for heat exchange between dispersed flows and a unit for continuous selective heating, comprising a heater and a mass-exchange apparatus, was proposed. A mathematical model of the unit was developed for the cases of direct-flow and counterflow heaters. Analytical solutions to the model equations were obtained. The parameters affecting the result of continuous selective heating of the dispersion medium in the unit were determined. 相似文献
120.
Z. Slanina 《Journal of Radioanalytical and Nuclear Chemistry》1990,142(2):525-529
Evaluation has been carried out of the component of the second virial coefficient of steam related to the formation of dimers. The necessary equilibrium constants of dimerization have been evaluated within the MCY-B water pair interaction potential. The calculated isotopic difference in the second virial coefficient reflects the qualitative features found by observation but, nevertheless, the calculation quite distinctly overestimates the value of this isotopic difference as compared with the observation. The nature of these differences and the relation to the state behaviour of water are discussed. 相似文献