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991.
Bruno Crociani Simonetta Antonaroli Franco Benetollo Matteo Bertoldini 《Journal of organometallic chemistry》2008,693(26):3932-3938
The preparation of the new ligand 8-(di-tert-butylphosphinooxy)quinoline (1) and the palladium derivatives [PdCl2(1)] (2), [Pd(η3-all)(1)]+ [all = C3H5 (3a), 1-PhC3H4 (3b) and 1,3-Ph2C3H3 (3c)] and [Pd(η2-ol)(1)] [ol = dimethyl fumarate (4a) and fumaronitrile (4b)] is reported. The cationic species 3a-3c have been isolated as salts. The complex 3a(BF4) is obtained either from the reaction of 1 with [Pd(μ-Cl)(η3-C3H5)]2 or from the reaction of ClP(CMe3)2 with [Pd(η3-C3H5)(8-oxyquinoline)], followed in both cases by chloride abstraction with NaBF4. In the complexes, the ligand 1 is P,N chelated to the central metal, as shown by the X-ray structural analysis of 3a(BF4). At 25 °C in solution, 3a(BF4) and 3b(BF4) undergo a fast η3−η1−η3 dynamic process which brings about a syn-anti exchange only for the allylic protons cis to phosphorus, while for 4a and 4b a slow rotation of the olefin around its bond axis to palladium takes place. The complexes 2 and 3a(BF4) are efficient catalyst precursors in the coupling of the phenylboronic acid with aryl bromides and chlorides. 相似文献
992.
Sterically hindered salicylaldimine functionalized imidazolium salts 2 have been prepared. The structures of the synthesized compounds were determined by spectroscopic techniques. The reaction of these salts containing arylmethyl-N chain (aryl: phenyl (2a), 2,4,6-trimethylphenyl (2b), 2,3,4,5,6-pentamethylphenyl (2c)) with Pd(OAc)2 in boiling toluene afforded Pd(II) complexes 3 in high yields. The X-ray structure of 1-[3-(3,5-di-tert-butyl-2-oxophenyl)propyliminato]-3-(2,4,6-trimethylbenzyl)imidazol-2-ylidenebromopalladium(II) (3b) has been determined. The Suzuki-Miyaura reaction was used to investigate their activity as catalysts either prepared in situ or from well-defined complexes. They are efficient when activated arylbromides are used as substrates. 相似文献
993.
The new ferrocenyl substituted ditertiary phosphine {FcCH2N(CH2PPh2)CH2}2 [Fc = (η5-C5H4)Fe(η5-C5H5)] (1) was prepared, in 72% yield, by Mannich based condensation of the known bis secondary amine {FcCH2N(H)CH2}2 with 2 equiv. of Ph2PCH2OH in CH3OH. Phosphine 1 readily coordinates to various transition-metal centres including Mo0, RuII, RhI, PdII, PtII and AuI to afford the heterometallic complexes {RuCl2(p-cym)}2(1) (2), (AuCl)2(1) (3), cis-PtCl2(1) (4), cis-PdCl2(1) (5), cis-Mo(CO)4(1) (6), trans,trans-{Pd(CH3)Cl(1)}2 (7) and trans,trans-{Rh(CO)Cl(1)}2 (8). In complexes 2, 3, 7 and 8 ligand 1 displays a P,P′-bridging mode whilst for 4-6 a P,P′-chelating mode is observed. All new compounds have been fully characterised by spectroscopic and analytical methods. Furthermore the structures of 1, 2 · 2CH2Cl2, 3 · CH2Cl2, 4 · CH2Cl2, 6 · 0.5CHCl3 and 8 have been elucidated by single crystal X-ray crystallography. Electrochemical measurements have been undertaken, and their redox chemistry discussed, on both noncomplexed ligand 1 and representative compounds containing this new ditertiary phosphine. 相似文献
994.
Abdallah Hamze 《Tetrahedron letters》2008,49(15):2429-2431
Totally regioselective hydrosilylation of functionalized terminal arylalkynes was achieved using PtCl2 associated with the air-stable and bulky Xphos ligand with various silanes. Regardless of the electronic nature of the substituents on the aromatic ring, a single β-(E)-vinylsilane was obtained in excellent yields. 相似文献
995.
A new type of supramolecular chiral phosphorus-based ligands was prepared from easily available monodentate ligands through complexation between dibenzylammonium salt and dibenzo[24]crown-8 macrocycle. Rhodium complexes with these supramolecular ligands were prepared, and the supramolecular bidentate ligand-containing catalyst has demonstrated better catalytic activity for all substrates, and higher enantioselectivity except for the ortho-substituted substrates than those obtained from the parent monodentate ligand in the asymmetric hydrogenation of α-dehydroamino acid esters. 相似文献
996.
New chiral N,N-bidentate 2,2′-bis-(4-isopropyl-4-methyl-4,5-dihydro-1H-imidazol-5-one) ligands have been prepared and characterised by their 1H and 13C NMR spectra and/or optical rotation. The ligands prepared were then tested for their ability to form complexes with copper(II) salts. It was found that the most stable complex is formed from the 2,2′-bis-(4-isopropyl-1,4-dimethyl-4,5-dihydro-1H-imidazol-5-one) ligand and copper(II) chloride. The structure of this complex was determined by means of quantum-chemical computations at the B3LYP or UB3LYP/6-31G(d,p) level. According to the computations, the geometry of the copper atom most resembles a tetrahedral arrangement, which was also confirmed by means of X-ray structural analysis. It was found that the structure of this copper(II) complex does not allow the copper atom to coordinate to additional ligands; therefore, it is catalytically inactive in the asymmetric Henry reaction. 相似文献
997.
André Gustavo de A. Fernandes Pedro Ivo da S. Maia Elizeu J. de Souza Sebastião S. Lemos Alzir A. Batista Ulrich Abram Javier Ellena Eduardo E. Castellano Victor M. Deflon 《Polyhedron》2008
Novel rhenium complexes containing the maltolate (mal) or kojate (koj) anions as chelating ligands have been synthesized: [ReOCl(mal)2] (1), [ReOCl2(mal)(PPh3)] (2), [ReOBr2(mal)(PPh3)] (3), [ReOCl2(koj)(PPh3)] (4) and [ReOBr2(koj)(PPh3)] (5). The products have been characterized by FTIR, 1H, 13C, and 31P NMR spectroscopies and elemental analysis. The crystal and molecular structures of all complexes were determined. Complex 1 crystallizes monoclinic, space group C2/c, Z = 8. It contains two O,O′-bidentate maltolate ligands and one chloro ligand at the (ReO)3+ unit, so that a distorted octahedral geometry is adopted by the six-coordinated rhenium(V) center. The chloro ligand occupies a cis position to the oxo ligand. Complexes 2 and 3 are isostructural and crystallize orthorhombic, space group Pbca and Z = 8. The isostructural complexes 4 and 5 crystallize monoclinic, space group P21/n and Z = 4. In complexes 2–5, the (ReO)3+ unit is coordinated by a monoanionic O,O-bidentate unit of the maltolate (2 and 3) or kojate (4 and 5) ligand, one triphenylphosphine and two halogeno ligands (Cl in 2 and 4; Br in 3 and 5), with the rhenium(V) center in a distorted octahedral environment. The halide ligands are in cis positions to each other. 相似文献
998.
Ronald Lindner Goran N. Kaluđerović Reinhard Paschke Christoph Wagner Dirk Steinborn 《Polyhedron》2008
Reactions of [PtMe3(OCMe2)3](BF4) and [(PtMe3I)4] with pyrazole (pzH) afforded mononuclear pyrazole platinum(IV) complexes [PtMe3(pzH)3](BF4) (1) and [PtMe3I(pzH)2] (2), respectively. The formation of dinuclear pyrazolato bridged platinum(IV) complexes (PPN)[(PtMe3)2(μ-pz)3] (3), (PPN)[(PtMe3)2(μ-I)(μ-pz)2] · 1/2Et2O (4) and [K(18C6)][(PtMe3)2(μ-I)(μ-pz)2] (5) was achieved by the reaction of each 1 and 2 with [PtMe3(OCMe2)3](BF4) in the presence of KOAc followed by reaction with (PPN)Cl (PPN+ = bis(triphenylphosphine)iminium cation) and 18C6, respectively. The reaction of complex 4 with AgO2CCF3 followed by addition of RSR′ (R/R′ = Me/Me, Me/Ph) resulted in the formation of complexes [(PtMe3)2(μ-pz)2(μ-RSR′)] (R/R′ = Me/Me, 6; Me/Ph, 7). All complexes were characterized unambiguously by microanalysis and NMR (1H, 13C) spectroscopic investigations. Additionally, crystal structures of complexes 3 and 4 as well as DFT calculation are presented. Furthermore, in vitro studies on the anti-proliferative activity of complexes 2 and 5 were carried out. 相似文献
999.
《Mendeleev Communications》2023,33(2):180-183
A simple one-step synthesis of (NHC)2NiCl2 complexes containing bulky N-heterocyclic carbene (NHC) ligands relies on the C–H metallation of N,N'-diaryl-substituted azolium salts, NHC-precursors, with NiCl2Py2 in the presence of Cs2CO3 and pyridine. This procedure allows one to implement all synthetic manipulations in air. 相似文献
1000.
K. L. Tokarev M. A. Kiskin A. A. Sidorov G. G. Aleksandrov V. N. Ikorskii I. P. Suzdalev V. M. Novotortsev I. L. Eremenko 《Russian Chemical Bulletin》2008,57(6):1209-1214
The mononuclear complexes (η3-terpy)M(Piv)2·MeCN (M = Fe
ii
(3) and Co
ii
(4), and Piv is the pivalate anion) were synthesized by the reactions of polymeric iron(ii) and cobalt(ii) pivalates with 2,2′:6′,2″-terpyridine (terpy). The oxidation of compound 3 affords the pentanuclear heterospin iron(ii,iii) complex (η3-terpy)Fe5(μ4-O)(μ3-OH)(μ-OH)2(μ-Piv)7(η1-Piv)2 (5). All compounds were characterized by X-ray diffraction.
Dedicated to the 90th anniversary of the L. Ya. Karpov Institute of Physical Chemistry.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1186–1190, June, 2008. 相似文献