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1.
First example of the formation of bipolar spiro σ-complexes from 6-bromo-5,7-dinitrobenzo[e]-1,2,3,4-tetrazine 1,3-di-N-oxide 总被引:1,自引:0,他引:1
Voronina V. A. Frumkin A. E. Kurbatov S. V. Churakov A. M. Smirnov O. Yu. Olekhnovich L. P. 《Russian Chemical Bulletin》2002,51(4):668-670
The reactions of 3,5,7-trimethyltropolone and 2-(N-benzylamino)tropone with 6-bromo-5,7-dinitrobenzo[e]-1,2,3,4-tetrazine 1,3-di-N-oxide afforded novel bipolar spiro -complexes. The kinetic and activation parameters of the R,S-enantiotopomerization of a chiral spiro -complex of 2-(N-benzylamino)tropone were determined using dynamic 1H NMR spectroscopy. 相似文献
2.
A critical analysis shows that the approach to the estimation of the charge transfer in the process of adsorption at the electrode/solution interface used by Vetter and Schultze in the general case is not justified without introduction of non-thermodynamic models. This approach can prove useful in the investigation of the electric double layer within the limits of applicability of Grahame's model. A number of cases can however be cited where the approach of Schultze and Vetter is inapplicable. The conclusions of Schultze and Vetter regarding the adsorption of hydrogen at platinum are apparently based on some misunderstanding. In this case the thermodynamic approach6, 23 should be used.It would be more correct to call the quantity γ “the formal coefficient of charge transfer”, rather than “the electrosorption valency”. 相似文献
3.
The determination of the formal charge transfer coefficient n2 from the equilibrium electrocapillary curves of the first kind (taken under the condition μTl+=const) leads to values which are close to the values of the quantity l of Lorenz, obtained from a.c. measurements. 相似文献
4.
[reaction: see text] The novel heterocyclic system 10 with the phenanthrene type skeleton, in which the benzene ring is annulated with two 1,2,3,4-tetrazine 1,3-di-N-oxide rings, is of considerable interest in the context of the high nitrogen system stability and from a heteroaromaticity standpoint. The step-by-step synthetic approach to this system involves treatment of 5 with N2O5, resulting in the first 1,2,3,4-tetrazine 1,3-dioxide ring formation. The following displacement of the chlorine atom at the 6-position with ammonia and subsequent repeated treatment with N2O5 results in the second 1,2,3,4-tetrazine 1,3-dioxide ring formation. The structure of 10 was confirmed by a 13C and 14N NMR study. 相似文献
5.
B.I. Podlovchenko N.A. Epshtein A.N. Frumkin 《Journal of Electroanalytical Chemistry》1974,53(1):95-104
The charging curves, the potentiodynamic curves and the isoelectric potential shifts have been measured on Pt, Rh and Ir electrodes in HF and HF + KF solutions in a Teflon cell. From the obtained data, the ΓH+?? curves and the Δσ?? curves of the first kind have been calculated by means of the thermodynamic theory of the hydrogen electrode. The ΓH+ values in 0.14 M HF and 0.3 M HF + 0.12 M KF are much less than in 0.005 M H2SO4 and 0.005 M H2SO4 + 0.5 M K2SO4 solutions. In the presence of F? anions, the potentials ?ε=0 and ?Q=0 are by 25–55 mV more anodic than in the presence of SO2?4 anions. In an acidified fluoride solution the values of σ are higher than in an acidified sulfate solution. The analysis of the results obtained leads to the conclusion that on platinum metals the fluoride anions in the ?r region investigated (from ?r = 0 to ?r = 900 mV) are the most weakly adsorbed anions. 相似文献
6.
Consider the regular and the conjugacy characters ofS
n as vectors in Euclidean space, with the standard inner product. Asn grows, the angle between them tends to zero and the ratio of their lengths tends to one. The two characters have therefore
asymptotically similar decompositions into irreducible components. 相似文献
7.
We use results from the modular representation theory of the groupsS
n and GL
n
(F
q
) to determine the rank of inclusion matrices. 相似文献
8.
9.
A comparative study was made of different time intervals characterizing nanosecond magnetization reversal of flat permalloy films. These intervals increase with increasing relative coercive force of the samples. The results obtained for the durations of the magnetization reversal by different methods are practically the same in the case of the fastest regimes and are different for the slow regimes.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 12, pp. 58–61, December, 1970. 相似文献
10.