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991.
Summary A series of 34 alkylcyclohexane hydrocarbons structurally related top-menthane, including all saturated, monoolefinic and aromatic structural precursors from cyclohexane, have been characterized by GC and MS. Kováts retention indices have been determined on five stationary phases (squalane, SE-30, Apiezon L, OV-225, PEG 20M) and the corresponding polarity, temperature and structural increments have been calculated. From the information acquired 10 alicyclic hydrocarbons have been identified for the first time in a pyrolysis naphtha. 相似文献
992.
R. A. Zhuk A. é. Berzinya V. N. Silinya é. é. Liepin'sh S. A. Giller 《Chemistry of Heterocyclic Compounds》1979,15(2):136-138
The photochemical chlorinatlon of tetrahydrofuran-2-carboxylic acid esters with chlorine at –15 to –20C leads primarily to the formation of 5-chlorotetrahydrofuran-2-carboxylic acid esters (70–80%). 4,5-Dihydrofuran-2-carboxylic acid and furan-2- carboxylic acid esters are formed as side products. The structures of the principal and side products were investigated by PMR and mass spectroscopy.Deceased.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 166–168, February, 1979. 相似文献
993.
F. Pérez-Giménez G. M. Antón-Fos F. J. García-March M. T. Salabert-Salvador R. A. Cercós-del-Pozo J. Jaén-Oltra 《Chromatographia》1995,41(3-4):167-174
Summary The possible relation existing between RF values obtained by thin-layer chromatography for a group of anilines with connectivity indices proposed by Kier and Hall has been studied. Using multivariable regression the corresponding connectivity functions, selected for their respective correlation coefficients, standard deviations, Snedecor's F and Student's t were obtained. Regression analysis of the connectivity functions gives a correct prediction of the experimental elution sequence for this group of substances on silica gel stationary phases and various mobile phases of different polarity. The corresponding random and stability studies of the different prediction models selected were carried out, showing good stability and null randomness in all cases. 相似文献
994.
M. Colomina P. Jiménez R. Pérez-Ossorio C. Turrión 《The Journal of chemical thermodynamics》1979,11(12):1179-1184
The enthalpies of formation in the crystalline state at 298.15 K of o-, m-, and p-t-butyl-benzoic acids have been determined by static-bomb calorimetry. Vapour-pressure determinations were made by the Knudsen-effusion technique and the sublimation enthalpies at the mean temperatures of the measurement ranges have been derived for the three acids. The values obtained are:
o-t-butylbenzoic acid | 476.2 ± 1.9 | 99.8 ± 0.4 | (at 314.6 K) |
m-t-butylbenzoic acid | 504.3 ± 1.6 | 103.0 ± 0.5 | (at 326.5 K) |
p-t-butylbenzoic acid | 502.9 ± 1.7 | 103.8 ± 0.4 | (at 334.1 K) |