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1.
The micelle formation of a poly(vinylphenol)-block-polystyrene diblock copolymer was studied in ethyl acetate, a nonselective solvent using α,ω-diamine. The copolymer formed
micelles in ethyl acetate in the presence of a small amount of the α,ω-diamine. Light scattering studies demonstrated that
the micellization was dependent on the grade, the bulkiness, and the conformation of the diamines. The copolymer needed more
diamine with the increasing grade of the diamine, due to a decrease in the basicity of the diamine. The bulkiness of the diamines
also reduced the efficiency of the micellization by hindering the formation of the hydrogen bond cross-linking. Similarly,
the conformation of the diamine affected the micellization, since the conformation determined the intramolecular spatial distance
between the animo groups. Trans-1,2-cyclohexanediamine was more effective than the cis-isomer to produce the micelles. Furthermore,
(1S,2S)-(+)-1,2-cyclohexanediamine, one of the mirror image isomers composing the trans-isomer, was more effective in producing
the micelles than the trans-isomer. The interaction between the mirror image isomers also obstructed the micellization. The
micellization, coupled with the thermoresponsivity of the micelles, were influenced by the solvent quality. The dissociation
of the micelles into unimers was suppressed in ethyl acetate, while the reconstruction was promoted, in comparison with those
in 1,4-dioxane and THF. 相似文献
2.
A novel micelle formation induced by the photo-Claisen rearrangement was attained using a poly(4-allyloxystyrene)-block-polystyrene (PASt-b-PSt) diblock copolymer. The photoreaction was performed in cyclohexane at room temperature without a catalyst. The conversion
of the 4-allyloxystyrene units reached 90% by irradiation for 24 h. The photo-Claisen rearrangement of PASt-b-PSt into poly(3-allyl-4-hydroxystyrene)-block-PSt quantitatively proceeded up to a 20% conversion; however, the elimination of the allyl groups competitively occurred
over the 20% conversion. The degrees of the photorearrangement and elimination showed good agreement in their material balance
throughout the course of the reaction. Both of the photorearrangement and elimination finally reached ca. 50% degrees over
60% conversion. The light-scattering studies demonstrated that the PASt-b-PSt copolymer with a 36-nm hydrodynamic diameter as unimers formed micelles with a 98-nm diameter by irradiation. 相似文献
3.
A new method is proposed for the synthesis of indole derivatives containing a chiral substituent at the nitrogen atom, which
includes the direct alkylation of indole derivatives with tert-butyl (2S)-(p-tolylsulfonyloxy)propionate, obtained from commercial
ethyl (S)-lactate with subsequent conversion to the corresponding p-toluenesulfonyloxy derivative by hydrolysis, and esterification.
Dedicated to Academician B. A. Trofimov on his 70th birthday.
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, 1391–1398, September, 2008. 相似文献
4.
Krisztián Bogár 《Central European Journal of Chemistry》2005,3(1):63-71
(R, R)-(−)-N, N′-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediaminocobalt(II) was encapsulated into MCM-22 using the zeolite synthesis method. The
encapsulated catalyst proved to be active in the oxidation of α-methylstyrene with NaOCl with higher specific activity than
the homogeneous catalyst. At the same time, this encapsulated catalyst was completely inactive in the hydrolytic kinetic resolution
of racemic styrene oxide. This observation is in a good correlation with the assumption of the cooperative bimetallic mechanism
proposed by Annis and Jacobsen. 相似文献
5.
G. A. Abakumov V. K. Cherkasov T. N. Kocherova N. O. Druzhkov Yu. A. Kurskii M. P. Bubnov G. K. Fukin L. G. Abakumova 《Russian Chemical Bulletin》2007,56(9):1849-1856
New sterically hindered functionalized o-quinones were synthesized by the 1,4-nucleophilic addition of secondary cyclic amines to 3,6-di(tert-butyl)-o-benzoquinone. The ability of these o-quinones to form o-semiquinone complexes with transition and main-group metals was studied by ESR spectroscopy in solution.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1786–1793, September, 2007. 相似文献
6.
M. Madesclaire V. P. Zaitsev J. V. Zaitseva S. Kh. Sharipova 《Chemistry of Heterocyclic Compounds》2007,43(10):1325-1332
A synthesis is reported for (4R,5R)-and (4S,5S)-4-hydroxymethyl-5-(4-nitrophenyl)oxazolidin-2-ones and (1′R,4R)-and (1′S,4S)-4-[hydroxy(4-nitrophenyl)methyl]oxazolidin-2-ones from (1R,2R)-and (1S,2S)-2-amino-1-(4-nitrophenyl)-1,3-propanediols. The effect of the experimental conditions on the formation of these compounds
was studied.
__________
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1562–1570, October, 2007. 相似文献
7.
E. A. Dikusar N. G. Kozlov T. D. Zvereva A. P. Yuvchenko L. A. Mel’nichuk 《Chemistry of Natural Compounds》2004,40(5):472-477
Previously undescribed esters 1b-21b were prepared by reaction of cetyl alcohol 1a, terpene alcohols 2a-16a, plant phenols 17a-19a, and alcohols 20a and 21a with m-C(7)-iso-propylcarboran-C(1)-carboxylic acid.Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 388–392, September–October, 2004. 相似文献
8.
9.
E. B. Tsupak M. A. Shevchenko V. V. Kostrub Yu. N. Tkachenko 《Russian Chemical Bulletin》2007,56(11):2330-2336
5-Aroyl-1,3,6-trimethyluracils were converted to pyrano[4,3-d]pyrimidinium salts. Reactions of the salts obtained with ammonia, primary amines, and hydrazine were studied.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2251–2257, November, 2007. 相似文献
10.
Ahmad Shaabani Ebrahim Soleimani Maria Darvishi 《Monatshefte für Chemie / Chemical Monthly》2007,138(1):43-46
Summary. The three-component condensation of aldehyde, N,N′-dimethylbarbituric acid and alkyl or aryl isocyanide afforded the corresponding furo[2,3-d]pyrimidine-2,4(1H,3H)-diones in 1-butyl-3-methylimidazolium bromide as an ionic liquid in high yields at room temperature within several minutes. 相似文献
11.
A new compound (5R, 10R)-3,8-dihydroxy-5,10-diethoxy-5,10-dihydrochromeno[5,4,3-cde]chromene monohydrate was obtained from 3,4-dihydroxybenzaldehyde in aerobic basic aqueous ethanol solution in the presence
of manganese chloride and triethylamine and crystallized in orthorhombic P212121 space group (denoted as 1). When 1 was recrystallized from aqueous methanol, it was transformed to another crystal (2) with the same composition but in P21/n space group. The drastic difference in the extensive hydrogen bond network makes 1 a 3D and 2 a 2D infinite supramolecular structure, respectively. 相似文献
12.
A number of paramagnetic derivatives of [6-tert-butyl-4-(5-tert-butyl-2-methyl-3,4-dioxocyclohexa-1,5-dien-1-yl)-3-methylcatecholato]triphenylantimony(v) were investigated by ESR spectroscopy.
The reactions of this complex with Cp2Co or LiCl in the presence of Hgmetal. lead to the formation of free (nonchelated) radical anion semiquiones. Chelated complexes are formed in the case of Tl(Hg),
Mn2(CO)10, Re2(CO)10, Sn2Ph6, Cu(met.), and CuCl + dppfc (dppfc is bis-diphenylphosphinoferrocene).
Dedicated to Academician A. L. Buchachenko on the occasion of his 70th birthday.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 2004–2009, September, 2005. 相似文献
13.
Summary. Alkylation of Reissert compounds with certain benzoquinolizinone derivatives followed by hydrolytic cleavage afforded the core of the title compounds
in a two step sequence. Finally, the lactam intermediates were reduced with DIBAH giving the target compounds, the structural and stereochemical assignments of which were achieved by 13C NMR spectroscopy.
Part of PhD thesis, LMU München, D 相似文献
14.
Electroactive conducting copolymers of aniline (ANI) and o-aminophenol (OAP) and two-layered poly(o-aminophenol) (POAP)/polyaniline (PANI) composites were prepared in aqueous acidic solution by electrode potential cycling.
Copolymerization was carried out at different feed concentrations of OAP and ANI on a gold electrode. A strong inhibition
of electropolymerization was found at a high molar fraction of OAP in the feed. The copolymers showed good adherence on the
electrode surface and gave a redox response up to pH=10.0. Two transitions were observed in the in situ conductivities of
the copolymers (as with PANI), but the conductivities were lower by 2.5–3 orders of magnitude as compared to PANI. Electrosynthesis
of PANI on POAP modified electrodes showed copolymer formation after reaction initiation and finally formation of a PANI layer
at the copolymer/solution interface. The ‘memory effect’ of the bilayer structures of both polymers was discussed in terms
of protonation/deprotonation and anion consumption taking place during redox processes of both polymers. 相似文献
15.
16.
Regina M. Q. Mello José P. M. Serbena Adriano R. V. Benvenho Ivo A. Hümmelgen 《Journal of Solid State Electrochemistry》2003,7(8):463-467
We report the electrochemical preparation of poly(p-phenylene) (PPP) thin films with a polymerization degree of approximately 20 using biphenyl as starting material. The PPP
films are prepared directly on a tin oxide electrode, presenting a positive charge carrier mobility of 5×10−7 cm2 V−1 s−1. 相似文献
17.
A new type of hexane-soluble polymeric surfactant based on poly(4-tert-butoxystyrene) (P
t
BSt) was prepared by the nitroxide-mediated living radical polymerization, and their self-assemblies in hexane were explored.
Polystyrene-block-P
t
BSt diblock copolymers with six different P
t
BSt block lengths were obtained by the sequential living radical polymerization of styrene followed by 4-tert-butoxystyrene using 4-methoxy-2,2,6,6-tetramethylpiperidine-1-oxyl as the mediator; Mn(P
t
BSt block) = 13,500, 21,700, 26,600, 47,500, 91,300, and 108,000 at the constant length of the PSt block (Mn = 12,900). Dynamic
light-scattering studies demonstrated that the copolymers self-assembled into monodispersed spherical micelles in hexane.
The hydrodynamic diameter of the micelles increased with an increase in the P
t
BSt block length. The micellar size also increased as the copolymer concentration increased. However, the size decreased as
a result of the increasing temperature due to a decrease in the aggregation number. The 1H NMR analysis confirmed that the copolymers formed micelles with PSt cores. 相似文献
18.
The kinetics of catalytic alkylation of 2,6-di-tert-butylphenol (ArOH) with methyl acrylate (MA) in the presence of potassium 2,6-di-tert-butylphenoxide (ArOK) depends on the method for the preparation of ArOK. The reaction of ArOH with KOH at temperatures >
180 °C affords monomeric ArOK, whose properties differ from those in the case of potassium 2,6-di-tert-butylphenoxide synthesized by the earlier methods. The regularities of ArOH alkylation depend on the ArOK concentration,
the ArOH: MA ratio, and the effect of microadditives of polar solvents.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1971–1974, October, 2007. 相似文献
19.
Solvent-controlled chemoselective palladium-catalyzed oligomerization of tert-butyl acetylene is reported in this paper. The reaction was carried out smoothly in benzene/n-BuOH binary solvent system. When unpolar aprotic benzene was the preponderating component in the binary system, a cyclotrimerization
process occurred to produce 1,3,5-tri-tert-butylbenzene via a mechanism of three acetylene molecules, inserted step by step, forming σ-butadienyl-Pd and σ-hexatrienyl-Pd intermediates. While when the polar, protic and strong coordinating component n-BuOH, which aids Cu(II) to cleave the C-Pd σ-bonds and solvate Pd(II), Cu(II) cations, halo anion, σ-butadienyl-Pd intermediate, etc., was increased to a certain extent in the binary solvent system, the reaction proceeded
readily via a n-BuOH-promoted mechanism to give (3Z,5Z)-2,2,7,7-tetramethyl-3,6-dichloro-3,5-octadiene or (3Z,5Z)-2,2,7,7-tetramethyl-3,6-dibromo-3,5-octadiene, respectively. Possible weak hydrogen bonds and n-π weak force between n-BuOH (electron pair donor (EPD)) and tert-butyl acetylene (and σ-butadienyl-Pd intermediate, electron pair acceptor (EPA)) in the latter process were also in favor of the n-BuOH promoted pathway. Meanwhile, the coupling product 2,2,7,7-tetramethyl-3,5-octadiyne was exclusively obtained when the
reaction was conducted in singular polar H2O. Influences of the solvent, catalysts, as well as possible mechanism were discussed in this paper. 相似文献
20.
E. A. Kaigorodova L. D. Konyushkin A. A. Osipova E. A. Gavrilova E. V. Gromachevskaya G. D. Krapivin 《Russian Chemical Bulletin》2004,53(12):2878-2880
A general method for the synthesis of 3-amino-2-(4,4-diphenyl-4H-3,1-benzoxazin-2-yl)thieno[2,3-b]pyridines was proposed. The method involves reactions of (3-cyanopyridin-2-ylthio)acetic acids or their amides with o-aminophenyl(diphenyl)carbinol in nitromethane in the presence of perchloric acid followed by neutralization of the resulting salts.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2759–2762, December, 2004. 相似文献