1,720,965 research outputs found
Crystal structure of mu(3)-oxo-esakis(mu(2)-acetate)triaquatrichromium(III) 2,6-dihydroxybenzoate dihydrate
No full textThe compound [Cr-2(mu(2)-CH3COO)(6)(mu(3)-O)(H2O)(3)]DHB . 2H(2)O (DHB = 2,6-dihydroxybenzoate(-1)), as characterized by single crystal X-ray analysis and spectroscopy, is described. The compound crystallizes in the monoclinic space group Cc with a = 14.122(3), b = 15.137(4), c = 14.952(3) Angstrom, beta = 99.70(3)degrees, Z = 4. The structure of the complex consists of the trimetallic cage common to 'basic' acetates of Cr(III), Fe(III) and Rh(III), where three metal ions lie at the comers of a nearly equilateral triangle of side similar to 3.3 Angstrom, the center being occupied by a triply-bridging oxygen. The chromium coordination is compared with those found in related complexes. The DHB anion is anchored to the trichromium moiety through bonding between the carboxylate group and a metal-bound water molecule
Chromium(III) acetate, chromium(III) acetate hydroxide, or mu(3)-Oxo-esakis-(mu(2)-acetato-O,O')-triaqua-trichromium(III) acetate? Determining the structure of a complex compound by analytical and spectroscopic methods
No full textCRYSTAL-STRUCTURE OF A POLYMERIC COMPLEX OF LEAD(II) WITH 2,6-DIHYDROXYBENZOIC ACID
No full textThe complex Pb2(DHB)4 . 3H2O (DHB = 2,6-dihydroxybenzoate(- 1)) has been prepared and characterized using single-crystal X-ray diffraction. The compound consists of a polymeric network which accommodates two types of lead ions. The coordination polyhedron around the first of them can be described as a distorted pentagonal bipyramid, where four carboxylate and one phenolic oxygens are the basal coordinating atoms, while the water molecule and a second phenolic group are in the apical positions. The second lead atom is involved in a dimeric Pb-Pb unit (metal-metal distance: 4.23 angstrom) bridged by two water molecules lying at distances of 2.59 and 2.61 angstrom, respectively. The coordination at each atom of this dimeric entity is completed by a bidentate carboxylate, a monodentate carboxylate, a water molecule and two phenolic groups resulting in a heavily distorted square antiprismatic stereochemistry. The Cd(II) complex is likely to have the same structure as the lead complex
MOLECULAR-STRUCTURE AND SPECTRAL PROPERTIES OF MONONUCLEAR AND DINUCLEAR COMPLEXES FORMED BY MANGANESE(II), 2,6-DIMETHOXYBENZOATE AND 2,2'-BIPYRIDINE OR 2-METHYLPYRAZINE
No full textThe adducts formed by reaction of [Mn(dmb)(2)(H2O)(3)](n) . nH(2)O, dmb = 2,6-dimethoxybenzoato(1-), with 2,2'-bipyridine (bpy) or 2-methylpyrazine (2-Mepz) were isolated in the solid state and characterized by single crystal X-ray diffraction, IR and EPR spectroscopy, and thermogravimetry. The adduct [Mn-2(dmb)(4)(bpy)(2)(H2O)(2)]. bpy crystallizes in the monoclinic space group P2(1)/n, with a = 15.983(4), b = 11.048(4), c = 17.682(4) Angstrom, beta = 97.66(3)degrees, V = 3094.4(16) Angstrom(3), A = 2 and D-calc = 1.415 g cm(-3). The complex exhibits a dinuclear structure where two manganese(II) atoms share two carboxylate groups adopting a rather uncommon single-atom bridging mode. The coordination at each metal nucleus is completed by a further carboxylate group, acting as a monodentate donor, a water molecule and a chelating bidentate bipyridine molecule. The crystals of the adduct [Mn(dmb)(2)(2-Mepz)(2)(H2O)(2)] are monoclinic, space group P2(1)/n, with a = 8.024(3), b = 10.314(3), c = 18.289(4) Angstrom, beta = 94.72(3)degrees, V = 1508.5(8) Angstrom(3), Z = 2 and D-calc = 1.412 g cm(-3). The compound is mononuclear and consists of hexacoordinate ions bound to trans-pairs of monodentate carboxylates, water molecules and nitrogenous base molecules. The bpy adduct exhibits EPR spectra distinctive of magnetically coupled dimanganese(II) units
Synthesis and chracterization of a novel tetranuclear bimetallic complex containing rhodium(II) and zinc(II) as metal centres
No full textPOLYMERIC COMPLEXES OF 3-HYDROXY-4-METHOXY AND 3-METHOXY-4-HYDROXYBENZOIC ACIDS - CRYSTAL-STRUCTURE OF THE LINEAR-CHAIN COMPLEX OF CO(II) WITH 3-HYDROXY-4-METHOXYBENZOIC ACID
No full textPOLYMERIC COMPLEXES OF 3-HYDROXY-4-METHOXY AND 3-METHOXY-4-HYDROXYBENZOIC ACIDS - CRYSTAL-STRUCTURE OF THE LINEAR-CHAIN COMPLEX OF CO(II) WITH 3-HYDROXY-4-METHOXYBENZOIC ACID
No full text
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
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
- …
