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1.
We have synthesized two forms of erbium tetracyanoplatinates, Er2[Pt(CN)4]3.21H2O (red form) and Er2[Pt(CN)4]2.SO4.11.5H2O (yellow form), and determined their crystal structures by X-ray diffraction. While the red form crystallizes in the orthorhombic space group Pbcn, with a = 15.4848(3) A, b = 13.8186(2) A, c = 19.07820(10) A, alpha = beta = gamma = 90 degrees, and Z = 4, the yellow form precipitates in the tetragonal space group I4cm, with a = b = 14.321(2) A, c = 13.338(3) A, alpha = beta = gamma = 90 degrees, and Z = 4. Both forms show [Pt(CN)4]2- chains but differ markedly in color and morphology. This is due to the incorporation of sulfate ions in the latter modification, leading to an increased Pt-Pt distance. The observed optical absorption and emission behavior of the title compounds is correlated with the Pt-Pt distances. 相似文献
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Graham Smith Urs D. Wermuth Peter C. Healy Jonathan M. White 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(4):o203-o207
The structures of two pseudopolymorphic hydrates of brucine, C23H26N2O4·4H2O, (I), and C23H26N2O4·5.25H2O, (II), have been determined at 130 K. In both (I) and (II) (which has two independent brucine molecules together with 10.5 water molecules of solvation in the asymmetric unit), the brucine molecules form head‐to‐tail sheet substructures, which associate with the water molecules in the interstitial cavities through hydrogen‐bonding associations and, together with water–water associations, give three‐dimensional framework structures. 相似文献
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Urs D. Wermuth Graham Smith Jonathan M. White 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(6):o353-o357
The structures of two brucinium (2,3‐dimethoxy‐10‐oxostrychnidinium) salts of the α‐hydroxy acids l ‐malic acid and l ‐tartaric acid, namely brucinium hydrogen (S)‐malate pentahydrate, C23H27N2O4+·C4H5O5−·5H2O, (I), and anhydrous brucinium hydrogen (2R,3R)‐tartrate, C23H27N2O4+·C4H5O6−,(II), have been determined at 130 K. Compound (I) has two brucinium cations, two hydrogen malate anions and ten water molecules of solvation in the asymmetric unit, and forms an extensively hydrogen‐bonded three‐dimensional framework structure. In compound (II), the brucinium cations form the common undulating brucine sheet substructures, which accommodate parallel chains of head‐to‐tail hydrogen‐bonded tartrate anion species in the interstitial cavities. 相似文献
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Graham Smith Urs D. Wermuth Jonathan M. White 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(11):o621-o624
The structure of brucinium dihydrogen citrate trihydrate (systematic name: 2,3‐dimethoxy‐10‐oxostrychnidinium dihydrogen citrate trihydrate), C23H27N2O4+·C6H7O7−·3H2O, has been determined at 130 K. The crystallographic asymmetric unit comprises two brucinium cations, two dihydrogen citrate anions and six water molecules of solvation. The two citrate anions, which are conformationally dissimilar, associate through extensive hydrogen‐bonding interactions with the common undulating brucinium cation layer substructures and the water molecules, forming a three‐dimensional framework polymer. 相似文献
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Abstract
The coordination polymer complex tetracesium bis(5-nitroisophthalate) heptahydrate [Cs4(C8H3NO6)2 (H2O)7] n has been synthesized and characterized using single-crystal X-ray diffraction. Crystals are monoclinic, space group P21/c, with Z = 4 in a cell with dimensions a = 12.3213(3), b = 6.7557(2), c = 36.2020(9) ?, β = 90.548(2)o. The complex is based on a repeating unit comprising four independent and different Cs coordination centres, two 6-coordinate, and two 8-coordinate [Cs–O, range 2.959(5)–3.386(5) ?], and seven water molecules, two of which are monodentate and the other five bridging, while all other oxygen atoms in the structure, including those of the nitro groups form inter-Cs bridges. Extensive water O–H···O hydrogen-bonding interactions give a three-dimensional framework. This structure represents the first of an alkali metal compound of 5-nitroisophthalic acid that has been reported. 相似文献7.
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