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1.
2.
G. I. Koldobskii Yu. E. Myznikov A. B. Zhivich V. A. Ostrovskii V. S. Poplavskii 《Chemistry of Heterocyclic Compounds》1992,28(6):626-631
In this review we discuss results obtained in the development of methods for the synthesis of tetrazoles and tetrazolium salts together with studies of alkylation, acylation, and imidoylation of tetrazole and 5-substituted tetrazoles under conditions of phase-transfer catalysis.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 754–761, June, 1992. 相似文献
3.
The general features of two series of sol-gel derived materials, designatedurethanesils (Ut), have been investigated by infrared and Raman spectroscopies with the goal of elucidating the chemical environment of
the Eu3+ cations.
The host frameworks of the two families of ormolytes studied have been represented by m-Ut(350) and d-Ut(300), where m stands
for mono, d stands for di, 350 and 300 are the average molecular weights of the organic precursors (poly(ethylene glycol)
methyl ether, PEGME, and poly(ethylene glycol), PEG, respectively).
The hybrid matrix of the mono-xerogels is composed by a siliceous backbone bonded by means of urethane linkages (-NHC (=O)O-)
to pendant methyl end capped oligopolymer chains with approximately 7 oxyethylene units, whereas that of the di-xerogels is
based on a siliceous network grafted through urethane groups to both ends of poly(oxyethylene) segments containing about 6
(OCH2CH2) repeat units.
Both classes of materials have been doped with europium triflate (Eu(CF3SO3)3). The doped samples have been identified by m-Ut(350)nEu(CF3SO3)3 and d-Ut(300)nEu(CF3SO3), where n is the molar ratio of (OCH2CH2) repeat units per Eu3+ ion. Materials with n ranging from ∞ to 5 have been analyzed. The spectral data obtained provide evidence that the cations
begin to coordinate to the ether oxygen atoms of the oligopolymer chains at n=40 in the mono-urethanesils and at n=10 in the
di-urethanesils. In mono-urethanesils samples with n>40 and in di-urethanesils materials with n>10, the Eu3+ coordinate exclusively to the carbonyl oxygen atoms of the urethane linkages.
Paper presented at the 8th EuroConference on Ionics, Carvoeiro, Algarve, Portugal, Sept. 16–22, 2001. 相似文献
4.
Yu. M. Berezanskii B. Ya. Levin V. A. Marchenko Yu. A. Mitropol''skii I. V. Ostrovskii 《Functional Analysis and Its Applications》1990,24(2):85-85
Obituary
Mark Grigor'evich Krein 相似文献5.
Esikov K. A. Morozova S. E. Malin A. A. Ostrovskii V. A. 《Russian Journal of Organic Chemistry》2002,38(9):1370-1373
Treatment of N-acetyl-(RS)-phenylalanine and N-acetyl-(RS)-leucine methyl esters with the system tetrachlorosilane-sodium azide leads to formation of tetrazole-containing amino acid derivatives. The latter can be converted into -substituted 5-methyl-1-tetrazolylacetic acids and the corresponding bis-tetrazoles. 相似文献
6.
K. A. Esikov V. Yu. Zubarev E. V. Bezklubnaya A. A. Malin V. A. Ostrovskii 《Chemistry of Heterocyclic Compounds》2002,38(8):986-991
We have obtained 5-phenyltetrazol-2-ylalkanoic acids and their derivatives containing terminal nitrile, amide, and tetrazol-5-yl groups. Tetrazolylalkanoic acids with two (pK
a 4.93) and three (pK
a 5.45) bridging methylene groups are weaker acids than the corresponding ditetrazoles pK
a 4.68 and 5.29 respectively). However, the acidity of 5-phenyltetrazol-2-ylacetic acid (pK
a 3.12), is higher than acidity of the corresponding ditetrazole (pK
a 3.27). 相似文献
7.
S. E. Morozova A. V. Komissarov K. A. Esikov V. Yu. Zubarev A. A. Malin V. A. Ostrovskii 《Russian Journal of Organic Chemistry》2004,40(10):1532-1538
Linear polynuclear tetrazole-containing compounds were synthesized. Alkylation of 5-[-(5-phenyl-2-tetrazolyl)alkyl]tetrazoles with ethyl bromoacetate and chloroacetamide gave the corresponding esters and amides. Treatment of the latter with tetrachlorosilane-sodium azide afforded compounds containing three tetrazole rings linked through polymethylene bridges. Acid ionization constants of the products possessing an NH-tetrazole ring (pK
a = 2.9–3.2) and the corresponding carboxylic acids (pK
a = 2.9–3.1) in aqueous methanol were determined by potentiometric titration.Translated from Zhurnal Organicheskoi Khimii, Vol. 40, No. 10, 2004, pp. 1580–1586.Original Russian Text Copyright © 2004 by Morozova, Komissarov, Esikov, Zubarev, Malin, Ostrovskii. 相似文献
8.
The heat effects and the rates and equilibrium quantities of H2O vapour sorbed and desorbed on polymeric perfluorinated materials (functional groups -SO3H, -SC3Na, -SO3K) and on material treated with FeCl3 solution as sorbent were investigated.Sorbed H2O may be completely desorbed in vacuum at 443 K. The material bearing -SO3H has maximum sorption affinity: the molar heat of -SO3H wetting is close to that of H2SO4 wetting. The differential heat of sorption decreases from 68 kJ mol–1 atn0(n=H2O/-SO3H) to 45 kJ mol–1 atn5, but not below the heat of H2O condensation. The -SO3H samples sorb H2O vapour in the presence of liquid H2O at 293 K up ton=17. The -SO3K material has minimum affinity for H2O: the equilibrium quantity sorbed in room air is less by a factor of 4 than that for the -SO3H material. The spatial arrangement of H2O molecules near the sulpho groups is considered. 相似文献
9.
V. A. Sazonov Yu. V. Ostrovskii G. M. Zabortsev V. V. Popovskii 《Reaction Kinetics and Catalysis Letters》1989,38(2):369-373
Kinetic regularities of the catalytic decomposition of ozone over IC-12-1 and ICT-12-9 cupric oxide catalysts in wetted gases have been studied. These catalysts are suggested to be effective for ozone decomposition.
-12-1 -12-9 . .相似文献
10.
I. Yu. Shirobokov M. V. Chekushina V. A. Ostrovskii G. I. Koldobskii G. B. Erusalimskii 《Chemistry of Heterocyclic Compounds》1988,24(4):413-417
Alkylation of 1-methyl-5-aryltetrazoles with dimethyl sulfate leads to the formation of 1,4-dimethyl-5-aryltetrazolium ion salts. Alkylation of isomeric 2-methyl-5-aryltetrazoles also apparently takes place at the N(4) atom. 1-Methyl-5-aryltetrazoles display greater reactivity with respect to methylation than the isomeric 2-methyl-5-aryltetrazoles. 1,4-Dimethyl-5-aryltetrazolium methylsulfate salts isomerize upon heating to give the more stable 2,4-dimethyl-5-aryltetrazolium ion salts.For Communication No. 22, see Ref. [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 502–506, April, 1988. 相似文献