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191.
The synthesis and preliminary solution phase ion binding properties of the N-tosylpyrrolidine calix[4]pyrrole 2 are reported. This β-octaalkyl-substituted calix[4]pyrrole, the first to be prepared via a direct condensation reaction, was obtained by reacting the 3,4-alkyl-functionalized pyrrole 8 with acetone in the presence of an acid catalyst. On the basis of (1)H NMR spectroscopic analyses and isothermal titration calorimetry, it was concluded that, compared with the parent, β-unsubstituted calix[4]pyrrole (1), compound 2 possesses significantly enhanced binding ability for halide anions in chloroform. Furthermore, 2 proved capable of solubilizing in chloroform solution the otherwise insoluble salts, CsF and CsCl. These effects are ascribed to the interactions between the four tosyl groups present in 2 and the counter cations of the halide anion salts. 相似文献
192.
Weinan Zhou Mengdi Hao Tian Lu Zhiming Duan Dr. Tridib Sarma Prof. Dr. Jonathan L. Sessler Dr. Chuanhu Lei 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(65):16173-16180
A pair of meso-unsubstituted expanded carbaporphyrins containing two carbazole moieties were prepared in high isolated yields (82 and 76 %, respectively). The two macrocycles, namely 3 and 4 , differ with respect to their substitution at the carbazole N-atoms i. e. by H and i-Bu, respectively. As prepared in their free-base forms, macrocycles 3 and 4 adopt figure-of-eight conformations and are best characterized as 40 π-electron, non-aromatic species possessing a decaphyrin(1.1.0.0.0.1.1.0.0.0) skeleton. Protonation of 3 with either trifluoroacetic acid (TFA) or perchloric acid (HClO4) produces a parallelogram-shaped structure. A similar structure is produced when N-functionalized system 4 is treated with TFA. In contrast, protonation of 4 with HClO4 leads it to adopt a twisted Möbius strip-like structure in the solid state, thus allowing access to three distinct conformational states as a function of the conditions. 相似文献
193.
Cover Picture: Design and Sensing Properties of a Self‐Assembled Supramolecular Oligomer (Chem. Eur. J. 6/2016)
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194.
Crystalline supramolecular architectures mediated by cations, anions, ion pairs or neutral guest species are well established. However, the robust crystallization of a well-designed receptor mediated by labile anionic solvate clusters remains unexplored. Herein, we describe the synthesis and crystalline behaviors of a trimacrocyclic hexasubstituted benzene 2 in the presence of guanidium halide salts and chloroform. Halide hexasolvate clusters, viz. [Cl(CHCl3)6]−, [Br(CHCl3)6]−, and [I(CHCl3)6]−, were found to be critical to the crystallization process, as suggested by the single-crystal structures, X-ray powder diffraction (XRPD), thermogravimetric analysis (TGA), scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS), and NMR spectroscopy. This study demonstrates the hitherto unexpected role that labile ionic solvate clusters can play in stabilizing supramolecular architectures.We report the synthesis and robust crystallization of a trimacrocyclic hexasubstituted benzene and guanidium mediated by unprecedented labile halide hexasolvate clusters, viz. [Cl(CHCl3)6]−, [Br(CHCl3)6]−, [I(CHCl3)6]−, and [Br(CHBr3)6]−. 相似文献
195.
Yannick Rio Dr. Wolfgang Seitz Andreas Gouloumis Dr. Purificacion Vázquez Prof. Jonathan L. Sessler Prof. Dr. Dirk M. Guldi Prof. Tomás Torres Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(6):1929-1940
A panchromatic 4,4‐difluoro‐4‐bora‐3a,4a‐diaza‐s‐indacene –zinc phthalocyanine conjugate (Bodipy–ZnPc) 1 was synthesized starting from phthalocyanine aldehyde 4 , via dipyrromethane 3 and dipyrromethene 2 . Conjugate 1 represents the first example in which a Bodipy unit is tethered to the peripheral position of a phthalocyanine core. Electrochemical and optical measurements provided evidence for strong electronic interactions between the Bodipy and ZnPc constituents in the ground state of 1 . When conjugate 1 is subjected to photoexcitation in the spectral region corresponding to the Bodipy absorption, the strong fluorescence characteristic of the latter subunit is effectively quenched (i.e., ≥97 %). Excitation spectral analysis confirmed that the photoexcited Bodipy and the tethered ZnPc subunits interact and that intraconjugate singlet energy transfer occurs with an efficiency of ca. 25 %. Treatment of conjugate 1 with N‐pyridylfulleropyrrolidine ( 8 ), an electron‐acceptor system containing a nitrogen ligand, gives rise to the novel electron donor–acceptor hybrid 1 ? 8 through ligation to the ZnPc center. Irradiation of the resulting supramolecular ensemble within the visible range leads to a charge‐separated Bodipy–ZnPc.+–C60.? radical‐ion‐pair state, through a sequence of excited‐state and charge transfers, characterized by a remarkably long lifetime of 39.9 ns in toluene. 相似文献
196.
197.
Jonathan L. Sessler 《Angewandte Chemie (International ed. in English)》1994,33(13):1348-1350
198.
Sessler JL Katayev E Pantos GD Ustynyuk YA 《Chemical communications (Cambridge, England)》2004,(11):1276-1277
A new 2,6-diamidopyridinedipyrromethane hybrid macrocycle () has been synthesized that shows a high selectivity for dihydrogen phosphate and hydrogen sulfate relative to nitrate in acetonitrile solution as judged from UV-vis spectrophotometric titrations; this leads to the suggestion that this or related systems might find use in nuclear waste remediation applications requiring the selective removal of hydrogensulfate from nitrate-rich waste mixtures. 相似文献
199.
200.
The synthesis, characterization, and X-ray structure of a heptapyrrolic macrocycle, [30]heptaphyrin(1.1.1.1.1.0.0) is reported; despite showing aromatic features, it exhibits a 'figure eight'-like structure in the solid state. 相似文献