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91.
Late transition metal (nickel, cobalt) complexes (1, 2) with β‐ketoamine ligand (L) based on the pyrazolone derivative are synthesized by condensing 1‐phenyl‐3‐methyl‐4‐benzoyl‐5‐pyrazolone with p‐fluoroaniline, and then treating the β‐ketoamine (L) produced with the respective metal halide. The bis(β‐ketoamine)metal complexes can act as catalyst precursors for norbornene polymerization with activation by methylaluminoxane. The effects of the central metal variation in the complex on catalyst activities and polymer microstructure are described. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
92.
U. M. Dzhemilev V. A. Dokichev I. O. Maidanova O. M. Nefedov Yu. V. Tomilov 《Russian Chemical Bulletin》1993,42(4):697-700
The stereochemistry of cyclopropanation of norbornenes with diazomethane in the presence of Cu, Pd, and Rh compounds has been studied. Stereoselectivity of the cyclopropanation depends on the nature of the transition metal and does not depend on its valent state or ligand environment. The reaction proceeds predominantly asexo-cycloaddition of the methylene fragment. The greatest amount ofendo-isomer (up to 47 %) is formed in cyclopropanation of norbornadiene andexo-tricyclo[3.2.1.02,4]oct-6-ene in the presence of Cu and Rh compounds.For part 11 see ref. 1.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 733–735, April, 1993. 相似文献
93.
94.
Pd(II) complexes bearing di‐ and monochelate fluorinated β‐ketonaphthyliminato ligand and their catalytic properties towards vinyl‐addition polymerization and copolymerization of norbornene and ester‐functionalized norbornene derivative 下载免费PDF全文
Fluorinated β‐ketonaphthyliminate ligand CF3C(O)CHC[HN(naphthyl)]CH3 ( L1 ) and Pd(II) complexes with dichelate fluorinated β‐ketonaphthyliminato ligand, {CF3C(O)CHC[N(naphthyl)]CH3}2Pd ( C1 ), as well as with monochelate fluorinated β‐ketonaphthyliminato ligand, {CF3C(O)CHC[N(naphthyl)]CH3}Pd(CH3)(PPh3) ( C2 ), were synthesized and their solid‐state structures were confirmed using X‐ray crystallographic analysis. The Pd(II) complexes were employed as precursors to catalyze norbornene (NB) homo‐ and copolymerization with ester‐functionalized NB derivative using B(C6F5)3 as a co‐catalyst. High activity up to 2.3 × 105 gpolymer molPd?1 h?1 for the C1 /B(C6F5)3 system and 3.4 × 106 gpolymer molPd?1 h?1 for the C2 /B(C6F5)3 system was exhibited in NB homopolymerization. Moreover, the Pd(II) complexes exhibited a high level of tolerance towards the ester‐functionalized MB monomer. In comparison with the C1 /B(C6F5)3 system, the C2 /B(C6F5)3 system exhibited better catalytic property towards the copolymerization of NB with 5‐norbornene‐2‐carboxylic acid methyl ester (NB‐COOCH3), and soluble vinyl‐addition‐type copolymers were obtained with relatively high molecular weights (3.6 × 104–7.5 × 104 g mol?1) as well as narrow molecular weight distributions (1.49–2.15) depending on the variation of monomer feed ratios. The NB‐COOCH3 insertion ratio in all copolymers could be controlled in the range 2.8–21.0 mol% by tuning a content of 10–50 mol% NB‐COOCH3 in the monomer feed ratios. Copolymerization kinetics were expressed by the NB and NB‐COOCH3 monomer reactivity ratios: rNB‐COOCH3 = 0.18, rNB = 1.28 were determined for the C1 /B(C6F5)3 system and rNB‐COOCH3 = 0.19, rNB = 3.57 for the C2 /B(C6F5)3 system using the Kelen–Tüdõs method. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
95.
Kazuhiro Morita Tamotsu Hashimoto Michio Urushisaki Toshikazu Sakaguchi 《Journal of polymer science. Part A, Polymer chemistry》2013,51(11):2445-2454
Cationic cyclopolymerizations of 2,2‐bis(vinyloxymethyl)bicyclo[2.2.1]heptane ( 1 ), 5,5‐bis(vinyloxymethyl)‐2‐bicyclo[2.2.1]heptene ( 2 ), and 2,2‐bis(vinyloxymethyl)tricyclo[3.3.1.1]3, 7decane ( 3 ), divinyl ethers with a norbornane, norbornene, or adamantane unit, respectively, were investigated with the HCl/ZnCl2 initiating system in toluene and methylene chloride at ?30 °C. All the reactions proceeded quantitatively to give gel‐free, soluble polymers in organic solvents. The number‐average molecular weight (Mn) of the polymers increased in direct proportion to monomer conversion and further increased on addition of a fresh monomer feed to the almost completely polymerized reaction mixture. The contents of the unreacted vinyl groups in the produced soluble polymers were less than ~10 mol %, and therefore, the degree of cyclization of the polymers was determined to be over ~90%. These facts show that cyclopolymerization of 1 , 2 , and 3 exclusively occurred and the poly(vinyl ether)s with the cyclized repeating units and polycyclic pendants were obtained with their molecular weights being regulated. BF3OEt2 initiator also caused cyclopolymerization of 1 , 2 , and 3 to give the corresponding high‐molecular‐weight cyclopolymers quantitatively. Glass transition temperatures (Tg's) of poly( 1 ) and poly( 2 ) were 165–180 °C, and Tg's of poly( 3 ) were 211–231 °C; these values are very high as vinyl ether polymers. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 2445–2454 相似文献
96.
近些年来,基于导向策略的Pd催化间位C(sp2)-H键活化反应取得了重要进展.人们通过远程导向策略,针对不同底物发展了多种U型导向基,在一些单保护氨基酸配体(MPAA)的协助下,实现了多种底物的烯基化、芳基化和乙酰氧基化反应.最近,人们又将Pd催化导向邻位C-H键活化和Catellani反应相结合,使用结构简单的导向基实现了高选择性的间位C-H键的烷基化和芳基化反应.这两种策略均可用于一些生物活性分子或者药物分子前体的后期修饰与合成当中.本文将针对这一领域的最新研究进展做一概述. 相似文献
97.
Il Gu Jung Soo Young Choi Youn K. Kang Young Keun Chung 《Journal of organometallic chemistry》2009,694(2):297-889
In situ generated cationic (η3-substituted allyl) palladium N-heterocyclic carbene (NHC) complexes are air-stable active catalysts for the olefin polymerization of (bicyclo[2.2.1]hept-5-en-2-yl)methyl acetate (5-norbornene-2-methyl acetate) (endo:exo = 7:3). Catalytic activities, polymer yields, molecular weights, and molecular weight distributions of polymers were investigated under various reaction conditions. The catalytic activity was highly dependent not only on the reaction condition such as a solvent or the reaction temperature but also on the structure of the catalyst that include substituents of the allyl group in the catalyst and the counter anion. As the bulkiness of the allyl group increased, the catalytic activity of the catalysts increased. 相似文献
98.
ZHANG Li ;CHEN Jian-Xina ;ZHANG Wen-Jie ;LI Ai-Ke ;ZHU Mei-Ping ;LIN Xin-Rong ;YU You-Yi ;ZHANG Zhi-Chun 《结构化学》2009,28(12):1666-1670
The title compound,bromo-(2-diphenylphosphino-N-(2-oxybenzylidene)-aniline)- nickel,was synthesized by simple condensation of 2-diphenylphosphino-N-(2-oxybenzylidene)- aniline with NiBr2·6H2O and characterized by elemental analysis,IR spectra and single-crystal X-ray diffraction. The crystal belongs to the triclinic system,space group P1 with a = 9.756(2),b = 10.232(2),c = 13.313(3)A,α = 95.09(3),β = 102.48(3),γ = 95.45(3)o,V = 1283.5(4) A^3,C29H23BrNNiO2P,Mr = 587.07,Z = 2,Dc = 1.519 g/cm^3,λ(MoKα) = 0.71073 A,F(000) = 596 and μ = 2.402 mm^-1. The structure was refined to the final R = 0.0408 and wR = 0.0965 for 4507 observed reflections (I 〉 2σ(I)). Intermolecular π-π interactions (with distances of about 3.705 A) are pronounced in the crystal structure. Under methylaluminoxane (MAO) activation,the title compound was able to catalyze norbornene polymerization,exhibiting good polymerization activities. 相似文献
99.
Johannes Carolus Jansen Raniero Mendichi Paolo Locatelli Incoronata Tritto 《Macromolecular rapid communications》2001,22(17):1394-1398
The kinetics of the ethylene‐norbornene copolymerization, catalyzed by rac‐Et(Ind)2ZrCl2/MAO, 90%rac/10%meso‐Et(4,7‐Me2Ind)2ZrCl2/MAO and rac‐H2C(3‐tert‐BuInd)2ZrCl2/MAO was followed by sampling from the reaction mixture at fixed time intervals. Catalyst activity, copolymer composition and molar mass were studied as a function of time. The polymers showed an unusually low polydispersity and a significant increase in their molar mass with time, suggesting a quasi‐living polymerization. 相似文献
100.
Hiromichi Fujioka Yasushi Nagatomi Naoyuki Kotoku Hidetoshi Kitagawa Yasuyuki Kita 《Tetrahedron》2000,56(52):10141-10151
An asymmetric desymmetrization of saturated and unsaturated cyclic and acyclic meso-1,2-diols has been developed from the ene acetals, prepared from the norbornene carboxyaldehyde and meso-1,2-diols. The intramolecular haloetherification of the ene acetals as a key step afforded 8-membered acetals in a stereoselective manner just by the reaction of norbornene olefin even when the ene acetals from unsaturated meso-1,2-diols having olefins in the same molecule were used. Subsequent reductive elimination, followed by protecting the hydroxy group and transacetalization, gave optically active 1,2-diol derivatives and the starting ene acetals in good yields. 相似文献