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951.
L. F. Kosyanchuk N. V. Kozak O. I. Antonenko G. Ya. Menzheres Yu. S. Lipatov 《Theoretical and Experimental Chemistry》2006,42(6):357-363
For semi-interpenetrating polymer networks (semi-IPNs) based on an incompatible polyurethane network/linear polymethylmethacrylate
pair formed in situ in the presence of 3d metal chelates, we have studied the effect of the system composition on the kinetics
of formation of the components and the nature of complex formation between the metal compound and the polymer matrix. The
ratio of the system components has been shown to have an effect on the selection of the macroligand in formation of complexes
of the metal chelate with the polar groups of the semi-IPN, where the general character of the kinetic behavior for the formation
of the network and the linear polymer is preserved.
__________
Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 42, No. 6, pp. 351–356, November–December, 2006. 相似文献
952.
The potential of a package of quantum-chemical software programs for exploring physicochemical problems pertaining to polyatomic organic molecules is highlighted. The results of investigation into the spectral, luminescent, and photochemical properties of molecules are discussed. The necessity of development of target-oriented models for studying the problems of physics and chemistry of molecules is emphasized. 相似文献
953.
Gavrilov K. N. Bondarev O. G. Polosukhin A. I. Lyubimov S. E. Tzarev V. N. 《Russian Journal of Coordination Chemistry》2002,28(2):143-145
Optically active amidophosphite with the peripheral imino group (R)-(Et2N)2POCH2CH(Et)N=CHPh is synthesized through one-stage phosphorylation of the corresponding imino alcohol. Its reaction with [Rh(CO)2Cl]2 (at P : Rh = 1) yields the mononuclear chelate [Rh(CO)(P^N)Cl]. Structures of the compounds are determined by IR, 31P, and 13C NMR spectroscopy, mass spectrometry, and polarimetry. 相似文献
954.
O. F. Smetanina T. A. Kuznetsova A. V. Gerasimenko A. I. Kalinovsky M. V. Pivkin P. C. Dmitrenok G. B. Elyakov 《Russian Chemical Bulletin》2004,53(11):2643-2646
A new sesquiterpene of the caryophyllene series, fuscoatrol A (1), and known compounds, 11-epiterpestacin (2) and -nitropropionic acid (3), were isolated from the marine fungus Humicola fuscoatra (Traaen) KMM 4629 associated with the Kuril colonial ascidium. The structure of 1 was established on the basis of X-ray diffraction data and 2D NMR spectroscopy. The antimicrobial and cytotoxic activities of compounds 1–3 were studied.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2534–2537, November, 2004. 相似文献
955.
A total synthesis of the above prenols has been carried out.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, pp. 2333–2338, October, 1991. 相似文献
956.
Rudolf O. Duthaler Peter Herold Susanne Wyler-Helfer Martin Riediker 《Helvetica chimica acta》1990,73(3):659-673
Chloro(cyclopentadienyl)bis(1,2:5,6-di-O-isopropylidene-α-D -glucofuranos-3-O-yl)titanium ( 1 ) is used for the transmetallation of Li-enolates obtained from propionyl derivatives. While such Ti-enolates of ketones and hydrazones appear to be unreactive, the (E)enolate 13 of 2,6-dimethylphenyl propionate ( 11 ) adds to the re-side of aldehydes, affording various syn-aldols 14 with high dia- and enantioselectivity (92–97% ds, 91–97% ee, cf. Scheme 2 and Table 1). Racemic syn-aldols (±)- 14 are obtained analogously from the achiral bis(2-propyloxy)-Ti-enolate 15 (Scheme 2 and Table 2). In contrast to the unstable Li-enolate 10 , the Ti-enolates 13 and 15 isomerize at ?30°, presumably to the thermodynamically more stable (Z)-enolates (Scheme 4), While the diastereoselectivity of the achiral enolate 15 is lost upon this equilibration, the chiral (Z)-enolate 27 quite unexpectedly affords anti-aldols 12 of high optical purity (94–98% ec) and, in most cases, with acceptable-to-good diastereoselectivity (82–90% ds). Notable exceptions are branched unsaturated and aromatic aldehydes which form a greater proportion of synepimers of moderate optical purity (Scheme 5 and Table 3). Consistent with these findings, re-facial-and ami -selective aldol-addition is also exhibited by the (Z)-configurated Ti-enolate 22 of N-propionyl-oxazolidi-none 19 (Scheme 3). 相似文献
957.
Converse A. O. Kwarteng I. K. Grethlein H. E. Ooshima H. 《Applied biochemistry and biotechnology》1989,(1):63-78
The results of an experimental study of the acid hydrolysis of hardwood are presented in the form of values for the three
parameters, activation energy, power on the acid concentration, and pre-exponen-tial factor, of the first order kinetic constants
for each of the following reaction participants: xylan remaining, glucan remaining, xylose formed, and xylose decomposed.
These are used as a base for a quantitative theory to predict the temperature, time, and acid concentrations needed for effective
pretreatment of the substrate for subsequent enzymatic hydrolysis of the glucan. This theory is based on the assumption that
successful pretreatment requires >90% removal of the xylan, <10% removal of the glucan, and >80% xylose yield. This theory
is compared with selected published data. 相似文献
958.
L. S. Vasil'ev O. G. Azarevich V. S. Bogdanov M. N. Bochkareva V. A. Dorokhov 《Russian Chemical Bulletin》1992,41(11):2104-2107
Boron chelates were obtained by the reaction of butoxy(butylthio)diphenylborane with 5,5,5-trifluoro(trichloro)-4-aminopent-3-en-2-one, and their reactions with primary amines were investigated. -Diiminate complexes of boron with trifluoro- and trichloromethyl groups were synthesized.N. D. Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, 117913 Moscow. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 11, pp. 2657–2661, November, 1992. 相似文献
959.
A. Damarupurshad R. J. Hart J. P. F. Sellschop H. O. Meyer 《Journal of Radioanalytical and Nuclear Chemistry》1997,219(1):33-39
Instrumental neutron activation analysis (INAA) has been applied to the analysis of 62 small (0.01–0.5 carat), single, inclusion-bearing and inclusion-free diamonds from South Africa, Brazil and Colorado. Up to 40 elements were detected at the ppb and ppt levels in individual diamonds of the eclogitic (basaltic affinity) and the peridotitic (ultramafic) paragenesis. The data obtained in this study can be used to distinguish between diamonds from the eclogitic and peridotitic parageneses and provides geochemical information on the environment in which diamonds crystallize. Further, the technique may prove to be useful in fingerprinting diamonds of different provenance areas. 相似文献
960.
A. N. Kornev O. S. Donnikova V. V. Semenov Yu. A. Kurskii 《Russian Chemical Bulletin》1995,44(1):145-148
A method for preparing (trichloromethyl)organosilanes by the catalytic decarboxylation of the corresponding trichloroacetoxysilanes RMe2SiOC(O)CCl3 (R = Me, ClCH2, Ph, Me3Si, and H) has been developed. The method involves heating the starting compounds without a solvent in the presence of a catalyst (quaternary ammonium salts or potassium salts with the addition of crown ethers). Tertiary amines (Et3N, Bu3N) catalyze this reaction only when heating is carried out in donor aprotic solvents (THF, acetonitrile) in the presence of oxygen. Thermal decomposition of (trichloroacetoxy)organosilanes, in contrast to catalytic decarboxylation, begins at a higher temperature and yields a mixture of products.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 150–153, January, 1995. 相似文献