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101.
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
102.
Samiul Islam Chowdhury Ryo Tanaka Yuushou Nakayama Takeshi Shiono 《Journal of polymer science. Part A, Polymer chemistry》2020,58(11):1564-1570
The copolymerization of norbornene (NB) and divinylbenzene (DVB) was carried out using anilinonaphthoquinone-ligated nickel complexes of the type [Ni(C10H5O2NAr)(Ph)(PPh3)] ( 1a : Ar = C6H3-2,6- iPr; 1b : Ar = C6H2-2,4,6-Me; 1c: Ar = C6H5) with modified methylaluminoxane (MMAO) as a cocatalyst. The DVB content was varied (5–25 mol%) and the resulting copolymers exhibited number-average molecular weights (Mn) of 40,000–69,000 g/mol with polydispersities (PDI = 1.5–1.8). The styryl group of the NB/DVB copolymer was used for grafting poly(methyl methacrylate) by reverse atom transfer radical polymerization using azobisisobutyronitrile in the presence of copper chloride and bipyridine. 相似文献
103.
Daria Jamroz Nathalie Fischer-Durand Marcin Palusiak Sławomir Wojtulewski Szymon Jarzyński Marlena Stępniewska Michèle Salmain Bogna Rudolf 《应用有机金属化学》2020,34(4):e5507
Novel transition metallocarbonyl complexes carrying a norbornene or an oxanorbornene group were synthesized by [4 + 2] cycloaddition between the organometallic maleimide dienophiles and cyclopentadiene or furan, respectively. The oxanorbornene adduct was obtained as a mixture of endo and exo isomers as confirmed by X-ray diffraction and NMR spectroscopy. The (oxa)norbornene groups further provided convenient chemical reporters to carry out inverse electron demand Diels-Alder (iEDDA) reactions with tetrazine derivatives. Detailed kinetic studies with a model tetrazine revealed that faster rates of reaction were determined with both isomers of the oxanorbornene complex with respect to the norbornene complexes. Eventually, incorporation of metallocarbonyl entities into bovine serum albumin equipped with tetrazine handles was achieved as shown by IR spectroscopy of the protein conjugates. 相似文献
104.
Nadja Noormofidi 《European Polymer Journal》2010,46(4):694-701
Two norbornene derivatives bearing phenantroimidazole dyes, namely endo/exo-11-(4-(1H-phenanthro[9,10-d]imidazol-2-yl)phenoxy) undecylbicyclo[2.2.1] hept-5-ene-2-carboxylat (5) and 11-(4-(1-Methyl-1H-phenanthro[9,10-d]imidazol-2-yl)phenoxy) undecylbicyclo[2.2.1]hept-5-ene-2-carboxylate (6) were synthesized. 5 and 6 were used to prepare statistical copolymers with endo,exo-bicyclo[2.2.1.]hept-2-ene-5,6-dicarboxylic acid dimethylester (7) via ring opening metathesis polymerization. The photophysical properties of the monomers and polymers and to what extent polymerization and substitution patterns influence the photophysical properties were investigated. Furthermore, the optical response upon addition of acid was investigated. The emission of monomer 5 shows a small bathochromic shift of 13 nm upon protonation while the emission of the resultant polymer poly5/7 exhibits a large red shift of 62 nm. In contrast, the according methylated monomer 6 and the resulting polymer poly6/7 gave similar absorption and emission characteristics. The differences were attributed to an increased tendency of the non-methylated dyes to interact when brought in close proximity in the polymer. 相似文献
105.
106.
Structural elucidation of dioxa‐cage compounds from tetrahydroisobenzofuran‐1(3H)‐one: analysis of NMR data and GIAO chemical shifts calculations 下载免费PDF全文
Gabriela da Costa Resende Elson Santiago Alvarenga 《Magnetic resonance in chemistry : MRC》2016,54(12):968-974
The polycyclic compounds, especially the dioxa‐cages, have attracted considerable attention in recent years. In our work, a series of 9β‐substituted 3‐oxo‐4,11‐dioxatetracyclo[5.2.1.15,8.02,6]undecane compounds were unexpectedly isolated during bromination, chlorination and epoxidation reactions of the 3‐hydroxy‐3a,4,7,7a‐tetrahydro‐4,7‐methanoisobenzofuran‐1(3H)‐one. After careful analysis of the NMR data, the chemical shifts of the isolated and the expected products were predicted by theoretical calculations using density functional theory and gauge including atomic orbitals. The best correlation between calculated and experimental data was evaluated by comparing mean absolute errors and applying DP4 probability methodology. Results from both approaches indicated a correct structural elucidation. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
107.
An efficient and convenient procedure has been developed for the ruthenium-catalyzed [2π + 2π] cycloadditions of dimethylacetylene dicarboxylate with norbornenes. Reaction is significantly accelerated in microwave conditions, while the commonly used benzene solvent was replaced by environmentally benign tetrahydrofuran.
108.
Naofumi Naga Yukio Imanishi 《Journal of polymer science. Part A, Polymer chemistry》2003,41(3):441-448
Copolymerization of ethylene or propylene and norbornene (NB) was carried out with stereospecific zirconocene catalysts rac‐ethylenebis(indenyl)zirconium dichloride, rac‐dimethylsilylenebis(indenyl)zirconium dichloride ( 2 ), rac‐dimethylsilylenebis(2‐methylindenyl)zirconium dichloride, and diphenylmethylene(cyclopentadienyl)(9‐fluorenyl)zirconium dichloride combined with cocatalysts at 40 °C. Temperature‐rising elution fractionation of the copolymers was carried out with cross‐fractionation chromatography with o‐dichlorobenzene as a solvent, and a broad distribution of the copolymer composition was detected. The fraction eluted at lower temperature contained higher NB. The effect of the polymerization time was examined in the ethylene–NB copolymerization with catalyst 2 , and the higher‐temperature elution fraction increased with increasing polymerization time. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 441–448, 2003 相似文献
109.
Karen Lienkamp Christoph F. Kins Sterling F. Alfred Ahmad E. Madkour Gregory N. Tew 《Journal of polymer science. Part A, Polymer chemistry》2009,47(5):1266-1273
Unprotected exo,exo‐5‐norbornene‐2,3‐dicarboxylic acid and exo,exo‐7‐oxa‐5‐norbornene‐2,3‐dicarboxylic acid were polymerized via ring‐opening metathesis polymerization. This reaction yielded polymers with molecular weights (Mn from GPC) ranging from 31 to 242 kg/mol and polydispersity indices between 1.05 and 1.12, using Grubbs' third generation catalyst. The water solubility as a function of pH value of the polymers was investigated by dynamic light scattering (DLS). DLS and acid‐base titration revealed that the oxanorbornene polymer was water soluble over a wider pH range than its norbornene analog. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 1266–1273, 2009 相似文献
110.
Gomboo Myagmarsuren Vitaly S. Tkach Dmitry S. Suslov Mikhail L. Chernyshev Fedor K. Shmidt 《Reaction Kinetics and Catalysis Letters》2007,90(1):137-143
Catalyst systems based on palaadium carboxylates and boron trifluoride etherate were examined in the dimerization of styrene,
telomerization of butadiene with diethylamine and homopolymerization of norbornene. The systems are shown to have higher efficiency
than their palladium β-diketonate prototypes at analogous conditions. 相似文献