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61.
62.
Takashi Hashimoto Takuma Nishimura Jong Min Lim Prof. Dr. Dongho Kim Prof. Dr. Hiromitsu Maeda 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(38):11653-11661
Bidipyrrin‐bridged macrocycles, prepared from NiII‐bridged dipyrrin‐based nanorings by intramolecular oxidative biaryl coupling reactions, yielded [2+4]‐type ZnII‐assisted stable twisted‐ring dimers comprising two double helices. These [2+4]‐type metal complexes can be optically resolved by chiral HPLC and exhibit tunable electronic and optical properties as a result of spring‐like motions. The double helices behave as glue to connect two macrocycles and as the screws of hinges to form thermally responsive synchronized spring systems. 相似文献
63.
Matthias Schulz Susanne Tanner Haitham Barqawi Wolfgang H. Binder 《Journal of polymer science. Part A, Polymer chemistry》2010,48(3):671-680
The end‐to‐end cyclization of telechelic polyisobutylenes (PIB's) toward cyclic polyisobutylenes is reported, using either ring‐closing metathesis (RCM) or the azide/alkyne‐“click”‐reaction. The first approach uses bisallyl‐telchelic PIB's (Mn = 1650, 3680, 9770 g mol?1) and Grubbs 1st‐, 2nd‐, and 3rd‐generation catalyst leading to cyclic PIB's in 60–80% yield, with narrow polydispersities (Mw/Mn = 1.25). Azide/alkyne‐“click”‐reactions of bisalkyne‐telechelic PIB's (Mn = 3840 and 9820 g mol?1) with excess of 1,11‐diazido‐undecane leads to the formation of mixtures of linear/cyclic PIB's under formation of oligomeric cycles. Subsequent reaction of the residual azide‐moieties in the linear PIB's with excess of alkyne‐telechelic PEO enables the chromatographic removal of the resulting linear PEO‐PIB‐block copolymers by column chromatography. Thus pure cyclic PIB's can be obtained using this double‐“click”‐method, devoid of linear contaminants. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 671–680, 2010 相似文献
64.
A series of 12‐ to 22‐membered macrocycles, with druglike functionality and properties, have been generated by using a simple and efficient copper‐catalyzed azide–acetylene cycloaddition reaction, conducted in flow in high‐temperature copper tubing, under environmentally friendly conditions. The triazole‐containing macrocycles have been generated in up to 90 % yield in a 5 min reaction, without resorting to the high‐dilution conditions typical of macrocyclization reactions. This approach represents a very efficient method for constructing this important class of molecules, in terms of yield, concentration, and environmental considerations. 相似文献
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Prins-type macrocyclizations have recently emerged as a successful strategy in the synthesis of polyketide-derived natural products. This reaction provides a concise and selective means to form tetrahydropyran-containing macrocyclic rings of varying size. A high degree of functionality within the macrocycle is tolerated and the yields for these transformations are typically good to excellent. Since the initial report of a Prins macrocyclization reaction in 1979, examples of this approach did not re-emerge until 2008. However, the use of this method in natural product synthesis has rapidly gained momentum in the synthetic community, with multiple examples of this macrocyclization tactic reported in the recent literature. 相似文献
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Dominik Lorbach Dr. Ashok Keerthi Dr. Teresa Marina Figueira‐Duarte Prof. Dr. Martin Baumgarten Dr. Manfred Wagner Prof. Dr. Klaus Müllen 《Angewandte Chemie (International ed. in English)》2016,55(1):418-421
First synthesis of the macrocycle cyclohexa(1,3‐pyrenylene) is achieved in six steps starting with pyrene, leading to a non‐aggregating highly twisted blue‐light‐emitting material. The cyclodehydrogenation of the macrocycle offers a promising synthesis route to holey‐nanographene. 相似文献
69.
Triptycene‐Based Chiral Macrocyclic Hosts for Highly Enantioselective Recognition of Chiral Guests Containing a Trimethylamino Group 下载免费PDF全文
Geng‐Wu Zhang Peng‐Fei Li Zheng Meng Han‐Xiao Wang Ying Han Prof. Chuan‐Feng Chen 《Angewandte Chemie (International ed. in English)》2016,55(17):5304-5308
A new class of chiral macrocyclic arene composed of three chiral 2,6‐dihydroxyltriptycene subunits bridged by methylene groups was designed and synthesized. Structural studies showed that the macrocyclic molecule adopts a hex‐nut‐like structure with a helical chiral cavity and highly fixed conformation. Efficient resolution was achieved through the introduction of chiral auxiliaries to give a couple of enantiopure macrocycles, which exhibited high enantioselectivity towards three pairs of chiral compounds containing a trimethylamino group. 相似文献
70.
Dr. Peter Schweyen Martin Hoffmann Jens Krumsieck Dr. Benedikt Wolfram Dr. Xiulan Xie Prof. Dr. Martin Bröring 《Angewandte Chemie (International ed. in English)》2016,55(34):10118-10121
Zinc and cadmium complexes of meso‐arylisoporphyrins carrying a pyrrolyl or dipyrrinyl substituent at the sp3 carbon atom were obtained through a simple one‐pot variation of the Alder–Longo porphyrin synthesis. Key to the formation and stabilization of isoporphyrins is the presence of metal acetates during the oxidative macrocyclization step. The characteristic Q‐bands of isoporphyrins are found in the NIR region between 750 nm and 880 nm. All of the isolated pyrrolyl‐ and dipyrrinyl‐appended isoporphyrins are stable under typical laboratory conditions and allow chemical transformations like BF2 coordination, transmetalation, and ligand exchange. 相似文献