The use of XeF2 for preparation of azepins

Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1841–1842, October, 1994.     

Dynamics of cavitational demolition in the interaction of a shock wave with a free surface

The problem of cavitation in the tension wave associated with the reflection of a shock wave from a free fluid surface is considered. A method of calculating the cavitation zone dynamics which makes it possible to determine the structure of the cavitation front, including for large space scales, is developed. A procedure for determining the dispersity of the fragment-drops of dispersed fluid, which takes into account the initial size distribution of the cavitation nuclei and the parameters of the incident shock wave, is proposed.Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No.6, pp. 73–80, November–December, 1992.     

Esters of 1-phosphorus-substituted cyclopropanecarboxylic acids

Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2150–2151, September, 1989.     

Synthesis of the hexapeptide L-phenylalanyl-L-prolyl-L-glutamyl-DL-phenylalanyl-L-valyl-L-leucine

Summary The synthesis of the ,-dimethyl ester of N-Cbo-L-phenylalanyl-L-prolyl-L-glutamyl-DL-phenylalanyl-L-valyl-L-leucine, not previously described in the literature, has been effected.T. G. Shevchenko Kiev State University. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 44–46, January–February, 1975.     

Analysis of the electronic excitations of the protonated forms of mono- and diacetyl derivatives of dibenzofuran,dibenzothiophene, and carbazole

The ^* electronic excitations of hydroxycarbonium (G-C (OH)- CH₃) and dihydroxycarbonium (CH₃- (OH)-G- (OH)-CH₃) ions, produced by the reaction of the corresponding acetyl and diacetyl derivatives of the heterocyles containing a biphenylene ring with 96% sulfuric acid, were investigated. A relationship was established between the structure of thse ions and their spectral characteristics. Analysis of the experimental data, the results of calculations by the PPP method, and the indices which quantitatively characterize the structure of the ^* electronic excitations, showed that two transitions (a strong transition of the p type and a weak transition of the type) are observed in the long-wave region (315–440 nm) of the electronic absorption spectra of the hydroxycarbonium ions. For the dihydroxycarbonium ions in this region of the spectrum there are doublets both for the p and for the a transitions. The origin of the electronic excitations of the dihydroxycarbonium ions is discussed in terms of orbital-configurational analysis and the resonance of the electronic excitations of the chromophores.Khar'kov University. Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 27, No. 1, pp. 33–39, January–February, 1991. Original article submitted September 22, 1988.     

Synthesis of thiophosphoryl-substituted derivatives of cycloalkanecarboxylic acids

The 1-thiophosphorylated esters and nitriles of cycloalkanecarboxylic acids were obtained both by the direct reaction of derivatives of thiophosphorylacetic acids with ,-dihalogenoalkanes in the K₂CO₃/DMSO heterophasic system, and as a result of the reaction of the corresponding oxygen compounds with the Louson reagent.A. N. Nesmeyanov Institute of Heteroorganic Compounds, Russian Academy of Sciences, 117813 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 2, pp. 391–397, February, 1992.     

Design rules for the large two-photon absorption diketopyrrolopyrrole-based quadrupolar symmetrical chromophores

Two-photon absorption of a series of symmetrical diketopyrrolopyrrole (DPP) derivatives is studied by means of density functional theory applied to second-order response function. Several important issues in modeling are highlighted which must be addressed for a reliable reproduction of the experimental results. A comparison of the theoretical results with the experimental ones indicates that the computed two-photon absorption (TPA) cross sections show a good agreement for the three-state model in case of symmetrical quadrupolar DPP derivatives with donor ending groups. Although the results of TPA cross section observed for the systems with strong electron accepting ending groups seem to be overestimated for the three-state model. At the same time using an algorithm for the direct calculation of the third-order processes by the solving dynamic coupled-perturbed Hartree–Fock equation shows relatively good qualitative results for both donor and acceptor ending groups; however, it was found to be less accurate quantitatively for the already published experimental results. Thus, to obtain a valid overview, supposedly, both methods have to be considered. In general, in the present paper, a strategy toward molecular tailoring of large TPA cross-sectional materials is described, which can be extremely useful tool to predict materials’ properties prior to synthesis and measurements.     

Tetraindole Derivatives of Porphyrins as Building Blocks in the Synthesis of Monodisperse Polyphenols

A new strategy for the synthesis of monodisperse polyphenols chemically bound to a rigid thermally stable molecular platform has been suggested. The platform has been prepared by the Suzuki–Miyaura reaction of a tetraboryl porphyrin derivative and 3-(4′-bromophenyl)-4,6-dimethoxyindole. Subsequent reactions of complete demethylation of obtained tetraindole and partial blocking of the corresponding phenolic hydroxyls by acid-labile protective groups have led to the formation of a final modified polyphenol compound of the porphyrin series. On the basis of the this polyphenol, a positive photoresist for lithography with exposure radiation at a wavelength of 13.5 nm has been developed; the photoresist affords the fabrication of topological structures with 16-nm resolution.     

Triindolyl Macrocycle as a Molecular Platform in the Synthesis of Sumanene-Containing Polyphenols

A new strategy has been suggested for the synthesis of sumanene-containing polyphenols chemically bound to a molecular platform based on the triindolyl macrocycle. The initial assembly has been obtained by the Suzuki–Miyaura reaction of a bromo-containing indolyl macrocycle and boryl derivative of N,N'-disumanenylaniline. Subsequent benzylation with 3,5-dimethoxybenzyl bromide, exhaustive demethylation of the modified macrocycle, and partial blocking of the corresponding phenolic hydroxyls by two different acid-labile protective groups have led to the formation of the target polyphenol containing sumanene fragments. The obtained polyphenol has allowed us to develop on its basis a new positive resist for electronbeam nanolithography. This resist can realize topological structures with resolution of 9–12 nm.