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991.
The reactions of the polysulfur and selenium cationic clusters S82+ and Se82+ with various iron carbonyls were investigated. Several new chalcogen containing iron carbonyl cluster cations were isolated, depending on the nature of the counteranion. In the presence of SbF6− as a counterion, the cluster [Fe3(E2)2(CO)10] [SbF6]2·SO2 (E = S, Se) could be isolated from the reaction of E82+ and excess iron carbonyl. The cluster is a picnic-basket shaped molecule of two iron centers linked by two Se2 groups, with the whole fragment capped by an Fe(CO)4 group. Crystallographic data for C10O12Fe3Se4Sb2F12S (I): space group monoclinic P21/c, A = 11.810(9), b = 24.023(6), c = 10.853(7) Å, β = 107.15(5)°, V = 2942(3) Å3, Z = 4, R = 0.0426, Rw = 0.0503. When Sb2F11− is present as the counterion, or Se4[Sb2F11]2 is used as the cluster cation source, a different cluster can be isolated, which has the formula [Fe4(Se2)3(CO)12] [SbF6]2·3SO2. The dication contains two Fe2Se2 fragments bridged by an Se2 group. Crystallographic data for C12O18Fe4Se6Sb2F12S3 (III): space group triclinic
, b = 18.400(9), C = 10.253(4) Å, = 93.10(4), β = 103.74(3), γ = 93.98(3)°, V = 1995(1) Å3, Z = 2, R = 0.0328, Rw = 0.0325. The CO stretches in the IR spectrum all show a large shift to higher wavenumbers, suggesting almost no τ backbonding from the metals. This also correlates with the observed bond distances. All the compounds are extremely sensitive to air and water, and readily lose SO2 when removed from the solvent. Thus all the crystals were handled at −100°C. The clusters seem to be either insoluble or unstable in all solvents investigated. 相似文献
992.
The reaction between the redox-active diphosphine ligand 4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione (bpcd) and the dirhenium compound Re2(CO)8(μ-H)(μ-η1,η2-C CPh) in CH2Cl2 at room temperature proceeds by CO loss to give the dirhenium complex Re2(CO)7(bpcd)(μ-H)(η1-C CPh) (1). This new complex was characterized in solution by IR and NMR (1H and 31P) spectroscopy and in the solid state by X-ray diffraction analysis. Re2(CO)7(bpcd)(μ-H)(η1-C CPh) crystallizes in the triclinic space group
γ = 69.240(6)°, V = 2024.9(3) Å3, Z = 2, dcalc = 1.862 g cm−3 R = 0.0221, Rw = 0.243 for 4066 observed reflections. The bpcd ligand in 1 adopts a chelating mode with a linear phenylacetylide ligand being located on the adjacent rhenium center cis to the bpcd ligand. This complex represents the first structurally characterized example of a hydrido-bridged dirhenium complex possessing both a linear acetylide ligand and a chelating diphosphine ligand. 相似文献
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993.
Terrence Nicholson Alan Davison Jon A. Zubieta Qin Chen Alun G. Jones 《Inorganica chimica acta》1995,230(1-2):205-208
The reaction of the neutral Tc(V) phenylimido complex [TcCl3(NPh)(PPh3)2] with excess PMe2Ph in refluxing MeOH gives the cationic, tris-dimethylphenylphosphine complex [TcCl2(NPh)(PMe2Ph)3]+, which is isolated as the tetraphenylborate salt. The IR spectrum of the crystalline product shows a medium intensity band at 1102 cm−1 which is assigned to ν(TcN) from the phenylimido core. The 1H NMR spectrum of the diamagnetic complex shows a series of multiplets in the aryl region and three distinct signals near 2 ppm from the phosphine methyl groups. The X-ray crystal structure, which is the first for a cationic technetium organoimido complex, shows a meridional arrangement of phosphine ligands with a chloride ligand coordinated trans to the phenylimido unit. The TcN bond length of 1.711(2) Å is consistent with the dianionic nature of the organonitrogen core. The Tc---N---C bond angle of 178.8(2)° reflects the sp hybridization of the phenylimido nitrogen atom. The coordination geometry is best described as a distorted octahedron. Crystal data for C54H58BCl2NP3Tc: triclinic space group . Structure solution based on 9986 observed reflections converged at R = 3.65%, Rw = 5.43%, GOF = 1.82. 相似文献
994.
Martin P. Waugh Roger J. Mawby Amanda J. Reid Richard J. Carter Colin D. Reynolds 《Inorganica chimica acta》1995,240(1-2):263-271
Complexes Ru(CO)2 (CH=CHR) (C6H4X-4)L2 (R=tBu, Ph, OEt; X=H, Cl, OMe; L=PMe3, PMe2Ph, P(OMe)2Ph) in which the two phosphorus ligands are mutually cis (isomer 1) react readily with ligands tBuNC, CO and P(OMe)3 to give complexes in which one of the organic ligands has migrated onto a carbonyl ligand. Vinyl migration products (5) retain the mutually cis geometry of the phosphorus ligands, and are unstable: one of the decomposition products is the ketone RCH=CHC(O)C6H4X-4. Phenyl migration products (4) are stable and have the phosphorus ligands in mutually trans positions; an X-ray crystal structure of Ru(CO) (CNtBu) {C(O)Ph} (CH=CHPh) (PMe2Ph)2 was obtained. In both cases, the incoming ligand enters trans to the newly formed acyl ligand. Vinyl migration is favoured over aryl migration by electron-donating substituents on the vinyl ligand, electron-withdrawing substituents on the aryl ligand, good σ-donor phosphorus ligands and use of tBuNC as the incoming ligand. The rate of phenyl migration in Ru(CO)2(CH=CHPh)Ph(PMe2Ph)2 is independent of tBuNC concentration: k=1.5 × 10−3 s−1 at 20°C. Isomer 3 of complexes Ru(CO)2(CH=CHR) (C6H4X-4)L2 in which the phosphorus ligands are mutually trans is much less reactive towards migration reactions. The reactivity of isomer 1 is attributed to the steric strain of two mutually cis phosphorus ligands. 相似文献
995.
Li-Juan Zhang Hua-Kuan Lin Xian-He Bu Yun-Ti Chen Xiao-Lan Liu Fang-Ming Miao 《Inorganica chimica acta》1995,240(1-2):257-262
A number of N,N′-bis(4-substituted phenyl)-1,7-diaza-12-crown-4 and N,N′-bis(4-substituted phenyl)-1, 10-diaza-18-crown-6 (where the substituents are OCH3, CH3, H, Cl, respectively) have been prepared by cyclization reaction of a ditosylate with the appropriately substituted diol. These new macrocyclic ligands have been characterized by means of elemental analysis, IR, 1H NMR and MS spectra. The crystal structures of N,N′-bis(4-chlorophenyl)-1,10-diaza-18-crown-6 (21) and its complex with barium thiocyanate Ba(SCN)2 (22) have been determined by single crystal X-ray diffraction. The crystallographic data are as follows: 21: C24H32Cl2N2O4, orthorhombic, P212121, A=4.852(1), B=11.989(2), C=41.231(8) Å, V=2398.7(8) Å3, Z=4; 22: C26H32Cl2N4O4S2Ba, monoclinic, P21/c, A=8.801(2), B=11.653(9), C=15.756(6) Å, ß=105.96(3)°, V=1553.7(14) Å3, Z=2. In the complex, the Ba atom is eight-coordinate (O(1), O(2), O(1)′, O(2)′, N(1), N(1)′, N(21), N(21)′) to form a distorted D6h geometry with the Ba atom at the center of crystallographic symmetry. 相似文献
996.
The labile cations [Cu(F-BF3)(PCy3)2] and [Cu(OTf)(PCy3)2] are versatile precursors for the formation of [Cu(X)(PCy3)2] (X = Br, I, SCN, N3) complexes by metathesis with NaX. The azide [Cu(N3)(PCy3)2] is triclinic, space group
, a = 9.755(4), B = 22.78(1), C = 9.284(6) Å, = 96.76(3), β = 115.36(3), γ = 94.20(5)°, Z = 2. 相似文献
997.
Isocyanide-substituted Re alkyl complexes cis-p-XC6H4CH2Re(CO)4(CN-p-tolyl) (X = Cl, OMe) were prepared from the PdO-catalyzed reaction of p-XC6H4CH2Re(CO)5 (X = Cl, OMe) with p-tolyl isocyanide. On heating in toluene these complexes undergo isocyanide insertion into the Re---C bond to afford iminoacyl complexes which further react to orthometallate the p-tolyl ring. An X-ray crystal structure determination on (CO)4 (3a) revealed that C19H13ClO4NRe crystallizes in the monoclinic space group P21/c with 4 formulas per unit cell. Unit cell parameters are a = 9.799 (1), B = 15.252 (2), C = 13.569 (2) Å and β = 110.788 (8)°. The structure shows Re---C bond distances indicative of substantial carbenoid character. 相似文献
998.
E. Joseph Billo Peter J. Connolly Dennis J. Sardella Jerry P. Jasinski Ray J. Butcher 《Inorganica chimica acta》1995,230(1-2):19-28
Conformations in solution of several diamagnetic nickel(II) complexes of macrocyclic tetraaza ligands are elucidated using proton NMR. There are six possible configurational isomers of planar [Ni(13aneN4)]2+ (13aneN4 = 1,4,7,10-tetraazacyclotridecane due to the orientation of the N---H protons above or below the plane of the macrocyle. Using NMR it is shown that in aqueous solution the [Ni(13aneN4)]2+ complex has the R,S,R,S or trans-II configuration. A single-crystal X-ray study demonstrates the same configuration of the nitrogen atoms in the complex [Ni(13aneN4)]ZnCl4. In the case of the 14-membered ring macrocyle cyclam (cyclam = 1,4,8,11-tetraazacyclotetradecane), previous NMR studies revealed the presence, in aqueous solution, of the previously unobserved trans-I or R,S,R,S isomer, whose spectrum is examined in greater detail here. Solution structures of nickel(II) complexes of bicyclam (1,5,8,12-tetraazabicyclo[10.2.2]hexadecane) and dachden (N, N′-bis(2-aminoethyl)-1,4-diazacycloheptane) are also reported. 相似文献
999.
J. -R. Hamon P. Hamon K. Boukheddaden J. Linars F. Varret D. Astruc 《Inorganica chimica acta》1995,240(1-2):105-108
The extremely air-sensitive 19-electron [FeICp hexaalkylbenzene)] complexes (alkyl = n-propyl, n-butyl, n-pentl) have been synthesized; variable-temperature Mössbauer data indicate a drastic decrease of the quadrupole splitting upon increasing temperature which does not correspond to a Boltzmann population of the upper Kramer's doublet due to the ‘chain effect’. It is proposed that an increasing proportion of the 17-electron Fe(I) state is involved as the chain length increases. 相似文献
1000.
Abstract: Two types of structures previously unrecorded in Erodium petals are investigated. Spherical hairs filled with liquid resembling nectar droplets are exclusive to an ibero-mauritanic group of species included in Erodium subsect. Romana. Broad flat hairs which reflect light, shining as do nectar droplets, are restricted to most of the species included in Erodium sect. Malacoidea. Long, simple hairs in petals and sepals are involved in collection of nectar droplets. Some of them are arranged at the margin of the petal claw, just over the nectaries. Others are on the internal surface of sepals or on the upper surface of petals, serving apparently the same function. Their shape is aciculate or flattened. The nectar collected among the hairs forms shining spherical droplets, perceptible to insects. The glistening flat hairs and spheres shine in a similar way, probably mimicking nectar and attracting insects. Species with these special nectar-like structures produce nectar in quantities that can be observed by the naked eye, suggesting that these structures increase the attraction efficiency of flowers. Some taxonomic and biogeographic consequences are also discussed. 相似文献