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31.
Milaeva E. R. Shpakovsky D. B. Shaposhnikova E. N. Grigor"ev E. V. Berberova N. T. Egorov M. P. 《Russian Chemical Bulletin》2001,50(4):716-719
-Aryl trans-bistriphenylphosphine complexes based on 2,6-di-tert-butylphenol containing Pt—SnCl3, Pt—GeCl3 groups were synthesized. Oxidation of these compounds gives the corresponding phenoxyl radicals, which were studied by ESR spectroscopy. The transformation of the diamagnetic complexes to the paramagnetic state is accompanied by cleavage of the Pt—Sn, Pt—Ge bonds and by elimination of SnCl2, GeCl2. 相似文献
32.
Kira Rubina Edgars AbelePavel Arsenyan Mendel FleisherJuris Popelis Alexander GaukhmanEdmunds Lukevics 《Tetrahedron》2003,59(38):7603-7607
Stereoselective transformations of 2-chlorovinylsulfides in the presence of soluble (t-BuOK) or insoluble (solid KOH or Cs2CO3/18-crown-6) base and palladium catalyst (dppb)Pd(OAc)2 have been studied. Depending on the substrate or catalytic system, the reaction leads to the formation of (E)-1,2-bis[aryl(or arylmethyl)thio]ethenes and/or (E)-1,4-bis[aryl(or arylmethyl)thio]-1-buten-3-ynes in yields of up to 93%. 相似文献
33.
Natalia V. Loginova Tat’yana V. Koval’chuk Rimma A. Zheldakova Anna A. Chernyavskaya Nikolai P. Osipovich Gennady K. Glushonok Henry I. Polozov Victor L. Sorokin Oleg I. Shadyro 《Central European Journal of Chemistry》2006,4(3):440-457
Cu (II) complexes with the sterically hindered diphenol derivatives 3,5-di(tert-butyl)-1,2-benzenediol (I), 4,6-di(tert-butyl)-1,2,3-benzenetriol (II) and the sulfur-containing 4,6-di(tert-butyl)-3-(2-hydroxyethylsulfanyl)-1,2-benzenediol (III) and 2-[4,6-di(tert-butyl)-2,3-dihydroxyphenylsulfanyl]acetic acid (IV) have been synthesized and characterized by elemental analysis, TG/DTA, FT-IR, ESR, XPS, XPD and conductivity measurements.
Compounds I–III can coordinate in their singly deprotonated forms and act as bidentate ligands. These compounds yield Cu (II) complexes of the stoichiometry Cu(L)2, which have square planar geometry (g| > g⊥ > ge). Unlike them, compound IV behaves as a terdentate ligand, and its complex Cu(LIV)2 has distorted octahedral geometry. According to ESR data, only the Cu(LII)2 complex contains a very small amount of phenoxyl radicals. Antimicrobial activities of these ligands and their respective
Cu (II) complexes have been determined with respect to Gram-positive and Gram-negative bacteria, as well as on yeasts. Their
phytotoxic properties against Chlorella vulgaris 157 were also examined. 相似文献
34.
We report herein an unprecedented protocol for radical carbotrifluoromethylation of unactivated alkenes. With Cu(OTf)2 as the catalyst, the reaction of unactivated alkenes, TMSCF3 and activated alkyl chlorides at room temperature provides the corresponding carbotrifluoromethylation products in satisfactory yields. Directed by trifluoromethylation of alkyl radicals, the method exhibits an excellent regioselectivity that is opposite to those driven by CF3 radical addition. 相似文献
35.
B. V. Lebedev L. Ya Tsvetkova N. N. Smirnova 《Journal of Thermal Analysis and Calorimetry》1994,41(6):1371-1377
The heat capacitiesC 0 p of polybutene-1, polypentene-1, poly-4-methylpentene-1 and 4-methylphentene-1 were studied calorimetrically from 6 to (500–700) K. Temperatures, enthalpies of melting of various crystalline forms and the parameters of the glass transition were determined. The thermodynamic functionsH 0(T)?H0(0), S0(T) andG 0(T)?H0 (0) were calculated between 0 K and (500–700) K. From the calorimetric values obtained and literature data, the thermodynamic characteristics of the following processes were estimated for the corresponding alkenes-1, andcis-andtrans-alkenes-2: the polymerization of alkenes-1, the monomer-isomerization polymerization ofcis- andtrans-alkenes-2 to polyaklenes-1 and the isomerization ofcis- andtrans-aklenes-2 to alkenes-1 in the same temperature interval at standard pressure. 相似文献
36.
Barluenga J Marco-Arias M González-Bobes F Ballesteros A González JM 《Chemistry (Weinheim an der Bergstrasse, Germany)》2004,10(7):1677-1682
An efficient protocol to synthesize iodohydrins from alkenes is presented. Reactions were conducted in aqueous media using safe and readily available sodium iodide (the most abundant form of the element), and a highly convenient oxidant such as hydrogen peroxide. Addition of a protic acid triggers a faster and efficient process, a role formally related to that played by haloperoxidase enzymes in naturally occurring transformations. The successful application of these conditions to multigram scale preparations and over natural products derivatives is also discussed. 相似文献
37.
PRODUCTION OF LIGHTOLEFINS FROM CO_2 HYDROGENATION OVER Fe/SILICALITE-2 CATALYST Ⅱ. PROMOTION EFFECT OF MnO PROMOTER 下载免费PDF全文
IntroductionItilasbeenshot'-nthattileadditionofMnOpromotertoFocatal}stcanresultinaremarkableimprovementinthesclectivit}'to11ghtalkenesforCOh}!drogenationll'l.Ho-c'cvcr.thecadetofMnOonCH4formationandCOconversionisvery'ambigUouslltolMoreover.MnOpromotergrca… 相似文献
38.
Davor Margetić Ronlad N. Warrener Mirjana Eckert-Maksić Ivana Antol Zoran Glasovac 《Theoretical chemistry accounts》2003,109(4):182-189
DFT calculations of 7′–oxasesquinorbornenes and 7,7′-dioxasesquinorbornenes using the B3LYP/6–31G* method are reported.
All the investigated structures (syn- and anti- derivatives) showed significant non-planarity of the central double bond, with the exception of those anti-derivatives possessing symmetrical structures. The influence of the replacement of the methylene groups at position 7- of
the norbornene fragment with oxygen and the introduction of second and third (peripheral) double bonds and benzene rings on
the molecular and electronic structures of these molecules have also been investigated.
Received: 11 November 2002 / Accepted: 6 June 2002 /
Published online: 29 April 2003 相似文献
39.
G. D. Kolomnikova D. Yu. Prikhodchenko P. V. Petrovskii Yu. G. Gololobov 《Russian Chemical Bulletin》1992,41(8):1497-1499
-Cyanoacrylic acid and -cyanoacrylates add dialkyl and diaryl phosphites and diethyl thiophosphite at the C=C double bond in the absence of catalyst. This is an anti-Markovnikov reaction, which yields the corresponding phosphonates and thiophosphonates.A. N. Nesmeyanov Institute of Organometallic Compounds, Russian Academy of Sciences, 117813 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1913–1915, August, 1992. 相似文献
40.
I. I. Kandror B. D. Lavrukhin M. A. Galkina Yu. G. Gololobov 《Russian Chemical Bulletin》1992,41(1):176-178
Syntheses are reported for representatives of a new class of derivatives of -cyanoacrylic acid, namely, its salts with brucine, tert-butyldimethylamine, and diisopropylmethylamine.A. N. Nesmeyanov Institute of Organometallic Compounds, Russian Academy of Sciences, 117813 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 1, pp. 212–214, January, 1992. 相似文献