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R. S. Él'kinson A. V. Eremeev É. E. Liepin'sh 《Chemistry of Heterocyclic Compounds》1985,21(5):521-525
The reaction of 2H-azirine with a number of dihydroxy thiols and dithiols leads to aziridin-2-yl alkyl sulfides. The latter readily isomerize to cyclic sulfides the size of the ring of which is determined by the length of the alkyl sulfide chain.For Communication 1, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 623–627, May, 1985. 相似文献
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55.
R. Jantas S. Poowiski J. Podeva 《Journal of polymer science. Part A, Polymer chemistry》1989,27(2):475-485
By reacting poly(methacryloyl chloride) (PMKC) with allyl amine, a multiallyl monomer in PMKC matrix has been obtained. Free-radical polymerization of multiallyl monomer in diluted solutions at a concentration of 12 g/L multiallyl monomer occurs partly along ordered allyl units in the matrix and results in ladder-type branched polymers. The polymers obtained are soluble in alcohols, DMF, DMSO and have unreacted allyl double bonds. The structures of multiallyl monomer and homopolymer have been found on the basis of elemental analysis, IR and 1H-NMR spectra and an examination of the products of hydrolysis. The effect of the reaction of degradative chain transfer on the structure of the polymer obtained has been discussed. 相似文献
56.
During nitroxide-mediated polymerization (NMP) in the presence of a nitroxide R2(R1)NO*, the reversible formation of N-alkoxyamines [P-ON(R1)R2] reduces significantly the concentration of polymer radicals (P*) and their involvement in termination reactions. The control of the livingness and polydispersity of the resulting polymer depends strongly on the magnitude of the bond dissociation energy (BDE) of the C-ON(R1)R2 bond. In this study, theoretical BDEs of a large series of model N-alkoxyamines are calculated with the PM3 method. In order to provide a predictive tool, correlations between the calculated BDEs and the cleavage temperature (T(c)), and the dissociation rate constant (k(d)), of the N-alkoxyamines are established. The homolytic cleavage of the N-OC bond is also investigated at the B3P86/6-311++G(d,p)//B3LYP/6-31G(d), level. Furthermore, a natural bond orbital analysis is carried out for some N-alkoxyamines with a O-C-ON(R1)R2 fragment, and the strengthening of their C-ON(R1)R2 bond is interpreted in terms of stabilizing anomeric interactions. 相似文献
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For ν≥0 let cνk be the k-th positive zero of the cylinder functionC v(t)=J v(t)cosα-Y v(t)sinα, 0≤α>π whereJ ν(t) andY ν(t) denote the Bessel functions of the first and the second kind, respectively. We prove thatC v,k 1+H(x) is convex as a function of ν, ifc νk≥x>0 and ν≥0, whereH(x) is specified in Theorem 1.1. 相似文献
59.
Conclusions On the example of the homolytic reaction of methallyl chloride with CCl4 it was found that iron pentacarbonyl in catalytic amounts can selectively suppress the radical process involving chlorine atoms, and at the same time it catalyzes the chain reaction with trichloromethyl radicals, which act as carriers of the kinetic chain.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, pp. 2320–2322, October, 1972. 相似文献
60.
B. Király F. Tárkányi S. Takács Z. Kovács 《Journal of Radioanalytical and Nuclear Chemistry》2006,270(2):369-378
Summary Excitation functions of proton induced nuclear reactions on natural Te were investigated up to 18 MeV. Cross sections for
production of 121,123,124,126,128,130gI and 121gTe were measured. The new experimental data were compared with the results of ALICE-IPPE model calculations and with data
found in the literature and measured on natural or enriched Te targets. The new data can be effectively used for validation
of recommended cross sections of medically relevant 123I and 124I. 相似文献