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1.
The electrochemical behavior of a film, which consists of intermediate products of the α,α,α′,α′-tetrabromo-para-xylol (TBX) reduction and is deposited on a glassy-carbon electrode from 5 × 10?2 M TBX solutions, is studied in 0.1 M Bu4NBF4 solution in DMFA by cycling the potential from 0 to ?1.4 V with respect to an aqueous saturated calomel electrode. When the potential is cycled from 0 to ?2.1 V in a cell filled with the supporting electrolyte, the film, which is assumed to have the (-BrHC-C6H4-CHBr-)n composition, can be reduced to form poly(para-phenylenevilylene) (PPV). This film exhibits redox activity in the cathodic range in solutions of Bu4NBF4 in DMFA and in both cathodic and anodic ranges in solutions of Bu4NBF4 in AN. It is observed for the first time that, if the cathodic limit of the potential cycling range is extended to ?2.5 V, the cathodic doping of PPV at potentials below ?2 V disappears and a new reversible redox process takes place at more negative potentials. 相似文献
2.
G. P. Girina N. M. Alpatova L. G. Feoktistov 《Russian Journal of Electrochemistry》2006,42(1):102-105
In the cyclic voltamograms for electrochemical reduction of α,α,α′,α′-tetrabromo-p-xylene at its concentrations of 5 and 10 mM in dimethylformamide solution of 0.1 M Bu4NBF4, taken at glassy-carbon electrode, four current peaks corresponding to consecutive stages of the reduction process are observed for the first time. The many times repeated potential cycling from 0 V (SCE) to the value approaching the 2nd peak potential results in the electrode passivation; a film of the intermediate product of the α,α,α′,α′-tetrabromo-p-xylene reduction is deposited at the electrode, whose composition may be-(BrCH-C6H4-CHBr-BrCH-C6H4-CHBr)n-. When the electrode covered with the deposited film is transferred to a solution of the same composition, in which the primary cycling was performed, yet free from α,α,α′,α′-tetrabromo-p-xylene, and underwent to potential cycling up to ?2V, the first cycle demonstrates a current peak that is due to the film reduction. A redox-active poly(p-phenylenevinylene) forms at the electrode. 相似文献
3.
Cyclopentanone or cyclohexanone were condensed with aromatic aldehydes to give corresponding α,α′-bis(R-benzylidene)cyclopentanones or α,α′-bis(R-benzylidene)cyclohexanones. The reaction was catalyzed by potassium hydrogen sulfate with a yield of 84–95% under
solvent-free conditions. 相似文献
4.
5.
I. M. Chung Mohd Ali A. Ahmad C. Y. Yu K. H. Ma J. G. Gwag Y. J. Park 《Chemistry of Natural Compounds》2005,41(6):650-653
One new compound 3,7,11,15,19-pentamethyl-9α,10α,11α,17α,18α-pentahydroxy-n-tetracosan-1-oxy-p-hydroxycaffeoate (oryzaterpenyl
caffeoate) (1), together with three known fatty acids linoleic acid, stearic acid and myristic acid were isolated and identified from the
rice grain of Oryza sativa. The structure of the new compound was elucidated by 1D and 2D NMR spectroscopic techniques (1H-1HCOSY, 1H-13C HETCOR) aided by EI-MS, and IR spectra.
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Published in Khimiya Prirodnykh Soedinenii, No. 6, pp. 535–537, November–December, 2005. 相似文献
6.
Yu. N. Belokon’ V. I. Maleev Z. T. Gugkaeva M. A. Moskalenko A. T. Tsaloev A. S. Peregudov S. Ch. Gagieva K. A. Lyssenko V. N. Khrustalev A. V. Grachev 《Russian Chemical Bulletin》2007,56(8):1507-1514
The synthesis of 1,2-, 1,3-, and 1,4-phenylene-bis[(4R,5R)-4,5-di(hydroxydiphenylmethyl)-1,3-dioxolane]s (ortho-, meta-, and para-bis-(R,R)-TADDOLs) and bis[4-{[(4R, 5R)-4,5-di(hydroxydiphenylmethyl)]-1,3-dioxolan-2-yl}phenyl]methane was carried out. The possibilities of the use of these compounds
as catalysts for the C-C bond formation in the addition of Me3SiCN to benzaldehyde and the oxirane ring opening in cyclohexene oxide by Me3SiCN were investigated. The catalytic activity of different bis-(R, R)-TADDOLs in this series depends on their structure.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1451–1458, August, 2007. 相似文献
7.
M. I. Mallyabaeva A. Yu. Spivak T. V. Tyumkina O. V. Knyshenko V. N. Odinokov 《Russian Chemical Bulletin》2007,56(12):2443-2447
Short and efficient synthesis of (3R,7R)-hexahydrofarnesyl bromide ((3R,7R)-1-bromo-3,7,11-trimethyldodecane), the terpenoid synthon for the natural α-tocopherol, has been elaborated based on the
microwave-activated regioselective enolization of homochiral phytone.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2360–2363, December, 2007. 相似文献
8.
Yue Zhang Natsumi Watanabe Yuuko Miyawaki Yutaka Mune Kenta Fujii Yasuhiro Umebayashi Shin-ichi Ishiguro 《Journal of solution chemistry》2005,34(12):1429-1443
Aprotic N,N-dimethylpropionamide (DMPA) and N,N,N′,N′-tetramethylurea (TMU) are both strong donor solvents and coordinate to metal ions through the carbonyl oxygen atom. These
solvents show a different conformational aspect in the bulk phase, i.e., DMPA exists as either a planar cis or a nonplanar staggered conformer, while TMU exists in a single planar cis conformer. It has been established that the manganese(II) ion is solvated by five molecules in both solvents. Interestingly,
although the planar cis conformer of DMPA is more favorable than the nonplanar staggered one in the bulk phase, the reverse is the case in the coordination
sphere of the metal ion, i.e., a conformational change occurs upon solvation. To reveal the thermodynamic aspect of this conformational change, the complexation
of Mn(II) with bromide ions in DMPA and TMU has been studied by titration calorimetry at 298 K. It was found that the Mn(II)
ion forms mono-, di- and tri-bromo complexes in both solvents, and their formation constants, enthalpies and entropies were
obtained. The Δ H∘1 value for MnBr+ strongly depends on the solvent, i.e., it is positive (19.4 kJ-mol−1) in DMPA and negative (−8.7 kJ-mol−1) in TMU, whereas the Δ H^∘2 and Δ H∘3 values for the stepwise formation of MnBr2 and MnBr3− are both small and negative. The enthalpy of transfer ΔtH∘ from DMPA to TMU, which is evaluated on the basis of the extrathermodynamic TATB assumption, is 25.5 kJ-mol−1 for Mn2+ and −3.6 kJ-mol−1 for MnBr+. These values indicate that the difference between the formation enthalpy of MnBr+ in the two solvents, Δ H^∘1 (DMPA) – Δ H∘1 (TMU), is mainly ascribed to the value of ΔtH∘(Mn2+). It is found that the metal ion is also five-coordinated in the monobromo complex, MnBr(DMPA)4+ . The enthalpy for the conformational change of DMPA from its planar cis to the nonplanar staggered form is evaluated to be −11 and −5.5 kJ-mol−1 for Mn(DMPA)52 + and MnBr(DMPA)4+, respectively. Note that these values are significantly smaller than the corresponding value (5.0 kJ-mol−1) in the bulk phase. We thus conclude that, although steric hindrance among solvent molecules is reduced by replacing one
DMPA of Mn(DMPA)52 + with the relatively small bromide ion, DMPA molecules are still sterically hindered in the MnBr(DMPA)4+ complex. 相似文献
9.
Yu. S. Kosenkova M. P. Polovinka N. I. Komarova D. V. Korchagina S. V. Morozov A. I. Vyalkov N. Yu. Kurochkina V. A. Cheremushkina N. F. Salakhutdinov 《Chemistry of Natural Compounds》2008,44(5):564-568
Flavones 2′,5′-dimethoxyflavone, 3′-methoxy-4′,5′-methylenedioxyflavone, 3′,4′-dimethoxyflavone, 5,6,2′,3′,6′-pentamethoxyflavone,
and 5,6,2′,3′,5′,6′-hexamethoxyflavone; salicylates, methyl-4-methoxysalicylate and peonol; and bisbibenzyl polyphenol riccardin
C were isolated for the first time from the acetone extract of the aerial part of Primula macrocalyx Bge. The content of free and total fatty acids was determined by GC and GC—MS. Palmitic (16:0), octadecatetraenoic 18:4 (6,9,12,15),
linoleic 18:2 (9,12), and α-linolenic 18:3 (9,12,15) were the principal acids from the aerial part of Primula macrocalyx.
Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 457–460, September-October, 2008. 相似文献
10.
11.
Ibrahim A. I. Ali Omar M. Ali Adel A.-H. Abdel-Rahman 《Monatshefte für Chemie / Chemical Monthly》2007,138(9):909-915
Summary. Methyl 2,3-O-isopropylidene-β-d-ribofuranoside was synthesized and oxidized with HIO4 to afford the corresponding carboxylic acid. The latter was coupled with the appropriate acylated amino acids in the presence
of HOBt and DDC as coupling reagents to give the corresponding amides. The methyl acetate derivative was hydrolyzed with 2 N KOH/MeOH to the corresponding carboxylic acid, which was coupled with l-glycine methyl ester to furnish the amide. Deprotection was carried out with 70% AcOH at reflux temperature. The prepared glycopeptides were tested for antiviral activity against Herpes Simplex virus type-1 (HSV-1) and hepatitis-A virus (HAV). The plaque reduction infectivity assay was used to determine virus count reduction as a
result of treatment with tested compounds. 相似文献
12.
N. N. Sidamonidze L. K. Janiashvili R. O. Vardiashvili R. A. Gakhokidze 《Chemistry of Natural Compounds》2006,42(2):127-128
A new synthesis of certain lactam-containing N-glycosides was developed. 2,3,4,6-Tetra-O-acetyl-β-D-gluco(galacto)pyranosylcaprolactams and 2,3,4,6-tetra-O-acetyl-β-D-gluco(galacto)pyranosylpyrrolidones were synthesized by condensation at room temperature of acetobromoglucose and acetobromogalactose
with ɛ-caprolactams and α-pyrrolidone.
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Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 105–106, March–April, 2006. 相似文献
13.
A. V. Aksenov A. V. Sarapii O. A. Antonova I. V. Borovlev V. I. Goncharov 《Chemistry of Heterocyclic Compounds》2005,41(8):1031-1035
The reaction of 1-alkyl-3-(2-quinolyl)quinolinium iodides with excess zinc in THF gives a diastereomeric mixture of 1,1′-dialkyl-3,3′-di(2-quinolyl)-1,1′,4,4′-tetrahydro-4,4′-biquinolyls.
An excess of lithium in THF gives a mixture of 1′,2′-dihydro-2,3′-biquinolyl and 1′-alkyl-1′, 4′-dihydro-2,3′-biquinolyl with
the former predominating. The reduction by lithium in THF of 1,1′-dialkyl-3,3′-di(2-quinolyl)-1,1′,4,4′-tetrahydro-4,4′-biquinolyls
leads to analogous products. Reduction of 1-alkyl-3-(2-quinolyl)quinolinium iodides by metallic potassium gives 1-alkyl-1′,4′-dihydro-2,3′-biquinolyls.
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Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1208–1212, August, 2005. 相似文献
14.
Subramanian Annalakshmi Kasi Pitchumani 《Journal of inclusion phenomena and macrocyclic chemistry》2007,57(1-4):403-408
The effect of cyclodextrin inclusion complex formation on the intramolecular charge transfer (ICT) of the included 4-N,N-dimethylamino-2-strylquinoline (2-StQ-NMe2) has been studied in detail. 2-StQ-NMe2 in presence of α-, β-, γ- and HP-α- and Hp-β-CDs predominantly exhibits ICT fluorescence predominantly than the emission
from locally excited state, whereas in presence of HP-γ-CD the later is observed. In presence of α-CD, 2:1 complexation of
the 2-StQ-NMe2 is observed in addition to 1:1 complexation. The observed results are explained by the CD cavity size and an active role
for the secondary hydroxyl groups present in the wider rim of the CD cavity and also which finds support from absorption,
emission, lifetime and molecular modeling studies.
Electronic supplementary material The online version of this article (doi: ) contains supplementary material, which is available to authorized users. 相似文献
15.
Vytautas Getautis Albina Stanisauskaite Rimgaile Degutyte Jolanta Stumbraite 《Monatshefte für Chemie / Chemical Monthly》2007,138(12):1293-1296
Summary. Intramolecular cyclization of N,N′-di(3-chloro-2-hydroxy)propyl-N,N′-diphenylbenzidine occurs to give bis-1,2,3,4-tetrahydroquinoline derivative 1,1′-diphenyl-1,2,3,4,1′,2′,3′,4′-octahydro-6,6′-biquinolinyl-3,3′-diol. 相似文献
16.
17.
We have developed a method of synthesis of benzo[5,6]indolizino[2,1-b]quinolinium-13-thiolates and 5,6-dihydrobenzo[5,6]indolizino[1,2-c]quinoline-6-thiones
based on the reaction of the corresponding 1′, 2′-dialkyl-1′,2′-dihydro-2,3′-biquinolines and 1′,4′-dialkyl-1′,4′-dihydro-2,3′-biquinolines
with sulfur in DMF.
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Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 849–851, June, 2007. 相似文献
18.
O. A. Antonova V. I. Goncharov A. V. Aksenov 《Chemistry of Heterocyclic Compounds》2006,42(2):197-199
1,1′-Dialkyl-3,3′-di(2-quinolyl)-1,1′,4,4′-tetrahydro-4,4′-biquinolines react with organolithium and organo-magnesium compounds
to form 1′-alkyl-2′-R-1′,2′-dihydro-2,3′-biquinolines.
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Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, 224–226, February, 2006. 相似文献
19.
Synthesis, structures, and properties of spiro[6-azaperimidine-2,4′-cyclohexa-2′,5′-dien]-1′-one derivatives 总被引:1,自引:0,他引:1
V. N. Komissarov E. N. Gruzdeva L. P. Olekhnovich G. S. Borodkin V. N. Khrustalev S. V. Lindeman Yu. T. Struchkov V. A. Kogan V. I. Minkin 《Russian Chemical Bulletin》1997,46(11):1924-1930
The reaction of 5-amino-4-chloroquinolines with 4-amino-2,6-di-tert-butylphenol yielded derivatives of spiro[6-azaperimidine-2,4′-cyclohexa-2′,5′-dien]-1′-one, which exhibit photo-and thermochromic
properties in solutions. The structure of 2′,6′-di-tert-butyl-5,7,9-trimethylspiro[6-aza,-2,3-dihydroperimidine-2,4′-cyclohexa-2′,5′-dien]-1′-one was established by X-ray diffraction
study. The ring-chain isomerization of 2′,6′-di-tert-butyl-5,7-dimethyl-and 2′,6′-di-tert-butyl-5,7,8-trimethylspiro[6-aza-2,3-dihydroperimidine-2,4′-cyclohexa-2′,5′-dien]-1′-ones was studied by dynamic NMR spectroscopy.
Deceased.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2028–2034, November, 1997. 相似文献
20.
T. V. Shokol O. A. Lozinskii T. M. Tkachuk V. P. Khilya 《Chemistry of Natural Compounds》2009,45(3):350-355
7-Hydroxy-3-phenoxy-8-formylchromones were synthesized using the Duff reaction and were reacted with 2,4-dinitrophenylhydrazine
to produce hydrazones and with an excess of hydrazine hydrate to produce the pyrazole recyclization products. Derivatives
of α-pyrono[2,3-f]chromones were synthesized using the Knoevenagel condensation with 2-azahetarylacetonitriles and the Perkin
reaction.
Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 298–302, May–June, 2009. 相似文献