1,721,063 research outputs found
(2S*)-2-Hydroxy-2- (2S*,5R*)-5-(1-hydroxy-1-methyl-ethyl)tetrahydrofuran -2-yl -1-phenylethanone
No full textThe molecules of the title compound, C15H20O4, link via a single intermolecular hydrogen bond to form chains running along the b axis
Methyl 2-hydroxy-2-[5'-hydroxy-5'-(1-hydroxy-1-methylethyl)-5,2'-dimethylperhydro-2,2'-bifuranyl-5-yl]acetate
No full textThe relative configuration was determined for the title compound, C16H28O7, which was obtained as a mixture of epimers. There are both intra- and intermolecular hydrogen bonds, the latter forming dimers around the crystallographic centres of inversion
Nicotinium nitrate monohydrate
No full textIn the title compound, C6H6NO2+center dot NO3-center dot H2O, the nicotinium cation is essentially planar. N-H center dot center dot center dot O, O-H center dot center dot center dot O and C-H center dot center dot center dot O hydrogen bonds link the molecules into layers parallel to the (101) plane
2-(4-pyridyl)pyrrolo 3,2-h quinoline
No full textThe structure of the title compound, C32H22N6, comprises two unique molecules that associate via N-H . . .N interactions to form a single convoluted hydrogen-bonded polymer chain. The dihedral angles between the indole rings and the substituted pyridyl rings are 13.43 (14) and 22.34 (12) Angstrom
Synthesis and structural features of the first thallium(I) selenoether derivatives
No full textThe first evidence for thallium(I) complexes involving selenoether ligands is presented, together with the structure determinations for the 1D chain species [Tl{MeSe(CH2)(3)Se-Me}]PF6 and the 3D network species [Tl{MeSe(CH2)(2)Se-Me}]PF6
Structure of uranium(VI) oxide dihydrate, UO3. 2H(2)O; synthetic meta-schoepite (UO2)(4)O(OH)(6). 5H(2)O
No full textThe structure of uranium oxide dihydrate, also known as meta-schoepite (UO2)(4)O(OH)(6). 5H(2)O, has been determined from a synthetic single crystal. The structure, at 150 K, space group Pbcn, lattice constants a = 14.6861 (4), b = 13.9799 (3) and c = 16.7063 (5) Angstrom, consists of layers of stoichiometry (UO2)(4)O(OH)(6), formed from edge-sharing UO7 pentagonal bipyramids, interleaved with hydrogen-bonded water molecules. Three of the layer hydroxyl groups are linked through hydrogen bonding to single water molecules and the three remaining OH units form interactions with water molecules that each act as acceptors in two hydrogen bonds. One of the water molecules in the inter-layer region is disordered over two symmetry-related sites and forms hydrogen-bonded interactions only within the layer and with the uranyl O atoms. The relationship of the structure of meta-schoepite to that of schoepite is discussed in detail
(1S*,4S*,5R*,8R*)-8-(3,4-Dimethoxyphenyl)-4-(3,4,5-trimethoxyphenyl)-3,7-dioxabicyclo(3.3.0)octan-2-one
No full textThe X-ray study of the title compound, C23H26O8, (I), confirmed the endo,exo-furofuranone structure of the important intermediate compound in the process of the total synthesis of (+/-)-epimagnolin A, which employs a new approach involving a highly diastereoselective CDH insertion reaction [Brown et al. (2001). Tetrahedron Lett. 42, 473-475]
Triisopropyl-(5-(4-nitrophenyl)tetrahydrofuran-3-ylidenemethyl)silane
No full textIn the title compound, C20H31NO3Si, the nitrophenyl groups of adjacent molecules overlap to form pi-pi-stacked pairs
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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