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排序方式: 共有261条查询结果,搜索用时 15 毫秒
141.
The synthesis of 5,15-bis[4-(methoxycarbonyl)phenyl]-10,20-diphenylporphyrin (2) and its reduction to 5,15-bis[4-(hydroxymethyl)phenyl]-10,20-diphenylporphyrin (3), and so its oxidation to provide 5,15-bis(4-formylphenyl)-10,20-diphenylporphyrin (4) are reported. The copolymer possessing β-cyclodextrin (β-CD), π-conjugated porphyrin and polyazomethine systems was synthesized by the polycondensation of porphyrin-dialdehyde monomer (4) and β-cyclodextrin/1,4-phenylenediamine complex (5). The monomers and the copolymer were characterized by UV-Vis, 1H-NMR and IR spectra. Furthermore, 1H-NMR and FT-IR spectra confirmed locating the aromatic ring of 1,4-phenylenediamine molecule in the center of β-cyclodextrin cavity. 相似文献
142.
Long Zhanga Xing Xin Caob Hai Xia Jiangb Biao Jiang Yu Xin Cui a State Key Laboratory of Natural Biomimetic Drugs School of Pharmaceutical Sciences Peking University Beijing China b 《中国化学快报》2009,20(6)
To investigate the structural form of gossypol and gossypolone Schiff's bases,seven relevant Schiff's bases were synthesized and the electrospray ionization-tandem mass spectrometry(ESI-MS/MS) with low-energy collision-induced dissociation was used to analyze their fragmentations.A common fragmentation pathway with the loss of RNH_2 from those schiff's bases quasi-molecular ions was observed and proposed on the basis of their MS/MS spectra data.This common pathway indicated that those Schiff's bases exis... 相似文献
143.
通过二茂铁甲醛与丙二胺反应得到双二茂铁基醛亚胺配体N~1,N~3-双二茂铁亚甲基丙烷-1, 3-二胺(FcMP), FcMP与MoO_2Cl_2(THF)_2的四氢呋喃溶液作用, 合成了双二茂铁基醛亚胺钼(VI)配合物. 以配合物为催化剂, 叔丁基过氧化氢为氧化剂, 分别以苯乙烯和环己烯为底物, 考察了温度、时间、催化剂量及溶剂对于烯烃均相环氧化反应的催化性能的影响. 结果表明, 在最优实验条件下, 反应12 h, 环己烯的转化率为88%, 环氧环己烷的选择性为98%;苯乙烯的转化率为84%, 氧化苯乙烯的选择性为76%. 催化剂经简单分离可回收使用, 且催化活性基本保持不变. 同时对环氧化反应的机理进行了初步探讨. 相似文献
144.
Po-Yuan Lu 《Tetrahedron》2009,65(36):7415-7421
The metal salts mediated oxidative free radical reaction of 2-amino-1,4-benzoquinones is described. Imine radicals can be generated by the oxidation of 2-amino-1,4-benzoquinones with Mn(III) and Ag(II). The dimeric products 4 and 14 were formed via the intermolecular radical coupling reaction of the corresponding radical intermediates 5 and 15. In the presence of styrene, twistane 17 was afforded from 2-phenylamino-1,4-benzoquinone 1 via a radical annulation reaction of imine radical 5. 相似文献
145.
An acyclic diimine ligand, H4L1, formed in methanol from the condensation of 1,4-diformyl-2,3-dihydroxybenzene (1) with two equivalents of 2-aminoethanol, was reacted with two equivalents of solid zinc(II) acetate dihydrate. Diffusion of diethyl ether into the reaction solution yielded a mixture of orange crystals of an octanuclear complex, [ZnII8(H2L1)4(OAc)8] (2), and red crystals of a hendecanuclear complex, [ZnII11(H2L1)6(OAc)6(O)2] (3). 相似文献
146.
147.
The control of the presence of OH−/CN− nucleophiles in an aqueous-ethanolic solution of [Mo(CN)4O(pcn)]2− anions (pcn = 2-pyrazinecarbonitrile) allows for selective transformation of the organonitrile ligand. The nucleophilic addition of CN− to the triple bond of the pendant nitrile group in pcn results in reduction of the nitrile group to an imine which is subsequently deprotonated and coordinated to the molybdenum(IV) atom in a bidentate mode to afford the complex anion [Mo(CN)3O(pnccn)]2− (Hpnccn = pyrazinecyanoimine), as revealed by its X-ray crystal structure. Such a synthetic and crystallographic demonstration of the reduction of an organonitrile with the capture of a metal-bound imine intermediate is uncommon. Elemental analysis verified the formulation [PPh4]2[Mo(CN)3O(pnccn)]·2.5H2O (1) and the physicochemical behaviour of [Mo(CN)3O(pnccn)]2− was investigated using spectroscopy (IR, UV–Vis and NMR) and cyclic voltammetry. The compound is the first known example with coordinated primary imine group among cyanocomplexes of Mo. The structural and spectroscopic properties of 1 are compared with those of the compounds resulting from the competitive metal-assisted ligand hydrolysis. The equilibrium constant for the protonation of the cyanoimine ligand, pK = 5.54 ± 0.03, has been determined by the spectrophotometric titrations at room temperature. 相似文献
148.
A multicomponent assembly process (MCAP) was utilized to prepare versatile intermediates that are suitably functionalized for subsequent cyclizations via Ullmann and Heck reactions to efficiently construct substituted 2,6-methanobenzo[b][1,5]oxazocines and 1,6-methanobenzo[c]azocines, respectively. The intramolecular Ullmann cyclization was conducted in tandem with an intermolecular arylation that enabled the rapid syntheses of a number of O-functionalized methanobenzoxazocines. 相似文献
149.
Biswanath Das Keetha Laxminarayana B. Ravikanth B. Ramarao 《Tetrahedron letters》2006,47(51):9103-9106
The allylation of aldehydes and imines has efficiently been carried out by treatment with allyltributylstannane in the presence of a catalytic amount of 2,4,6-trichloro-1,3,5-triazine at room temperature to form the corresponding homoallylic alcohols and amines, respectively, in high yields. 相似文献
150.
Narinder SinghDoo Ok Jang 《Tetrahedron letters》2011,52(20):2608-2610
An imine linked fluorescent receptor for AMP has been synthesized with both hydrogen bond donor and hydrogen bond acceptor motifs as recognition sites in the design of a receptor. The receptor recognizes AMP selectively over a number of tested anions and biomolecules such as ADP and ATP, as illustrated through fluorescent enhancement. 相似文献