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881.
882.
883.
Conclusions Primary amino alcohols react with CO in the presence of mercuric acetate at 100–200° and a pressure of 100–150 atm to give the corresponding N-(hydroxyalkyl)formamides in a yield of 1.4–2.5 M/M of reacted Hg(OCOCH2)3. Morpholine under analogous conditions forms the corresponding formyl derivative and the urea derivative in a 1.2–51 ratio, while cyclohexylamine forms the same derivatives in an 0.7 1 ratio.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1533–1536, July, 1973. 相似文献
884.
885.
L. A. Shchukina R. G. Vdovina Yu. B. Shvetsov A. V. Karpova 《Russian Chemical Bulletin》1962,11(2):286-288
Summary A preparative method was developed for obtaining L-and D-2-hydroxy-3-methylbutyric acids by the separation of racemic 2-hydroxy-3-methylbutyric acid with the aid of D-and L-threo-2-amino-1-p-nitrophenyl-1,3-propanediols. 相似文献
886.
The reaction between cumene hydroperoxide (CHP) and anhydrous hydrogen chloride under various conditions of temperature and concentration has been studied in an inert solvent (chlorobenzene) and in an oxidisable medium (cumene). The kinetics were first order with respect to each reactant; the energy of activation of the overall second-order reaction was 53.4 kJ mol?1 K?1. Competing ionic and free radical mechanisms were found to operate, the latter predominating at relatively high HCl concentrations, leading to rapid pro-oxidation in cumene. The effect of typical organo-tin PVC stabilizers on the pro-oxidant process were examined. It was found that dibutyltin maleate neutralized the HCl thus eliminating the pro-oxidant effect when used in stoichiometric proportions, but had little other effect. Dioctyltin bis(isol-octylthioglycollate) on the other hand not only neutralized the HCl stoichiometrically but gave additional oxidative stabilization over a wide concentration range. 相似文献
887.
888.
889.
The Nature of the vibronic intensity borrowing mechanism in the 1B3u(n)1Ag() transition of pyrazine
The transition intensities of the S0S1 gas phase absorption spectra of pyrazine-d0 and -d4 were carefully measured. A discussion of the various aspects of vibronic intensity borrowing for this unique case is presented using our new experimental results. 相似文献
890.
V. I. Khleskov B. N. Burykin R. É. Garibov 《Theoretical and Experimental Chemistry》1985,21(2):139-145
A quantum-chemical analysis of the electronic structure of two low-spin complexes, viz., bis(imidazole)hemichrome [Fe(III)P]2Im (S = 1.2) and bis(imidazole)hemochrome [Fe(II)P]·2Im (S = 0), which simulate hemi- and hemoproteins (P denotes porphyrin, Im denotes imidazole, and S is the spin of the iron ion), has been carried out by the extended Hückel method with SCF convergence with respect to the charges of the atoms. The data on the electronic structure of the complexes have been used for calculations of the quadrupole splitting in the57Fe Mössbauer spectra of these compounds. An analysis of the contributions of the valence electrons of the Fe atom and the ligands to the quadrupole splitting as a function of the structure of the iron ion, its electronic environment, and the parameters of the first coordination sphere has been carried out. Good agreement between the calculated and experimental values of the quadrupole splitting has been obtained. An analysis of the orbital interactions has been carried out, and data on the classification and composition of the MO's have been presented.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 21, No. 2, pp. 146–153, March–April, 1985. 相似文献