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101.
A Modular Class of Fluorescent Difluoroboranes: Synthesis,Structure, Optical Properties,Theoretical Calculations and Applications for Biological Imaging
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Sylvestre P. J. T. Bachollet Dr. Daniel Volz Béla Fiser Stephan Münch Dr. Franziska Rönicke Dr. Jokin Carrillo Harry Adams Prof. Ute Schepers Enrique Gómez‐Bengoa Prof. Stefan Bräse Prof. Joseph P. A. Harrity 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(35):12430-12438
Ten borylated bipyridines (BOBIPYs) have been synthesized and selected structural modifications have been made that allow useful structure–optical property relationships to be gathered. These systems have been further investigated using DFT calculations and spectroscopic measurements, showing blue to green fluorescence with quantum yields up to 41 %. They allow full mapping of the structure to determine where selected functionalities can be implemented, to tune the optical properties or to incorporate linking groups. The best derivative was thus functionalised with an alkyne linker, which would enable further applications through click chemistry and in this optic, the stability of the fluorophores has been evaluated. 相似文献
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A Boron‐Fluorinated Tris(pyrazolyl)borate Ligand (FTp*) and Its Mono‐ and Dinuclear Copper Complexes [Cu(FTp*)2] and [Cu2(FTp*)2]: Synthesis,Structures, and DFT Calculations
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Dr. Timo Augenstein Franziska Dorner Kevin Reiter Hanna E. Wagner Dr. Delphine Garnier Prof. Dr. Wim Klopper Prof. Dr. Frank Breher 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(23):7935-7943
Reaction of [Si(3,5‐Me2pz)4] ( 1 ) with [Cu(MeCN)4][BF4] ( 2 ) gave the mono‐ and dinuclear copper complexes [Cu2(FTp*)2] ( 3 ) and [Cu(FTp*)2] ( 4 ). Both complexes contain the so‐far unprecedented boron‐fluorinated FTp* ligand ([FB(3,5‐Me2pz)3]? with pz=pyrazolyl) originating from 1 , acting as a pyrazolyl transfer reagent, and the [BF4]? counter anion of 2 , serving as the source of the {BF} entity. The solid‐state structures as well as the NMR and EPR spectroscopic characteristics of the complexes were elaborated. Pulsed gradient spin echo (PGSE) experiments revealed that 3 retains (almost entirely) its dimeric structure in benzene, whereas dimer cleavage and formation of acetonitrile adducts, presumably [Cu(FTp*)(MeCN)], is observed in acetonitrile. The short Cu???Cu distance of 269.16 pm in the solid‐state is predicted by DFT calculations to be dictated by dispersion interactions between all atoms in the complex (the Cu?Cu dispersion contribution itself is only very small). As revealed by cyclic voltammetry studies, 3 shows an irreversible (almost quasi‐reversible at higher scan rates) oxidation process centred at Epa=?0.23 V (E01/2=?0.27 V) (vs. Fc/Fc+). Oxidation reactions on a preparative scale with one equivalent of the ferrocenium salt [Fc][BF4] (very slow reaction) or air (fast reaction) furnished blue crystals of the mononuclear copper(II) complex [Cu(FTp*)2] ( 4 ). As expected for a Jahn–Teller‐active system, the coordination sphere around copper(II) is strongly distorted towards a stretched octahedron, in accordance with EPR spectroscopic findings. 相似文献
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Dr. Priyabrata Ghana Dr. Franziska D. van Krüchten Dr. Thomas P. Spaniol Prof. Dr. Jun Okuda 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(45):10718-10723
Protonolysis of the titanium alkyl complex [Ti(CH2SiMe3)(Xy-N3N)] (Xy-N3N=[{(3,5-Me2C6H3)NCH2CH2}3N]3−) supported by a triamidoamine ligand, with [NEt3H][B(3,5-Cl2C6H3)4] or [PhNMe2H][B(C6F5)4] afforded the cations [Ti(Xy-N3N)][A] (A−=[B(3,5-Cl2C6H3)4]− ( 1[B(ArCl)4] ; B(ArCl)4=tetrakis(3,5-dichlorophenyl)borate); A−=[B(C6F5)4]− ( 1[B(ArF)4] ; B(ArF)4=tetrakis[3,5-bis(trifluoromethyl)phenyl]borate). These Lewis acidic cations were reacted with coordinating solvents to afford the cations [Ti(L)(Xy-N3N)][B(C6F5)4] ( 2-L ; L=Et2O, pyridine and THF). XRD analysis revealed a trigonal monopyramidal (TMP) geometry for the tetracoordinate cations in 1[B(ArX)4] and trigonal bipyramidal (TBP) geometry for the pentacoordinate cations in 2-L . Variable-temperature NMR spectroscopy showed a dynamic equilibrium for 2-Et2O in solution, involving the dissociation of Et2O. Coordination to the titanium(IV) center activated the THF molecule, which, in the presence of NEt3, underwent ring-opening to give the titanium alkoxide [Ti(O(CH2)4NEt3)(Xy-N3N)][B(3,5-Cl2C6H3)4] ( 3 ). Hydride abstraction from Cβ,eq of the triamidoamine ligand arm in [Ti(CH2SiMe3)(Xy-N3N)] or [Ti(NMe2)(Xy-N3N)] with [Ph3C][B(3,5-Cl2C6H3)4] led to the diamidoamine–imine complex [Ti(R){(Xy-N=CHCH2)(Xy-NCH2CH2)2N}][B(3,5-Cl2C6H3)4] (R=CH2SiMe3 ( 4 a ); R=NMe2 ( 4 b )). Hydride addition to 4 b with [Li(THF)][HBPh3] gave [Ti(NMe2)(Xy-N3N)], whereas KH deprotonated further to give [Ti(NMe2){(Xy-NCH=CH)(Xy-NCH2CH2)2N}] ( 5 ). XRD on single crystals of 3 and 4 b confirmed the proposed structures. 相似文献
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Markus Gellesch Franziska Hammerath Vicky Süß Marcel Haft Silke Hampel Sabine Wurmehl Bernd Büchner 《Journal of nanoparticle research》2017,19(9):307
The increasing interest in nanoscale materials goes hand in hand with the challenge to reliably characterize the chemical compositions and structural features of nanosized objects in order to relate those to their physical properties. Despite efforts, the analysis of the chemical composition of individual multi-element nanoparticles remains challenging—from the technical point of view as well as from the point of view of measurement statistics. Here, we demonstrate that zero-field solid-state nuclear magnetic resonance (NMR) complements local, single particle transmission electron microscopy (TEM) studies with information on a large assembly of chemically complex nanoparticles. The combination of both experimental techniques gives information on the local composition and structure and provides an excellent measurement statistic through the corresponding NMR ensemble measurement. This analytical approach is applicable to many kinds of magnetic materials and therefore may prove very versatile in the future research of particulate magnetic nanomaterials. 相似文献
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