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Correction to: Double end-on azido derivative of a tridentate (NNO) Schiff base dimeric copper(II) complex: synthesis, X-ray structure, magnetic property and catalytic effectiveness (Journal of Coordination Chemistry, (2020), 73, 20-22, (3062-3078), 10.1080/00958972.2020.1836360)
No full textWhen the article was published online, the author name Dariusz Bieńko had not been included in the article. Now, this had been added and republished online
Cyanide bridged 2-D homometallic mixed-valence copper coordination polymer: synthesis, crystal architecture, Hirshfeld surface analysis and magnetic behavior
No full textA 2-D homometallic mixed-valence copper coordination polymer, catena-poly[[tetrakis(μ-cyanido)-{(1-(N-acetopyridinine)-2-aminoethane)}-tri-copper] methanol monosolvate], {[Cu3(L)(CN)4]·CH3OH}n (1) [L = 1-(N-acetopyridinine)-2-aminoethane], has been isolated using a one-pot reaction of the building components and was characterized. The crystal structure consists of [CuIIL]2+ units and copper(I) ions bridged by μ-CN anions. The copper(II) center of the CuN5 chromophore displays a square pyramidal coordination geometry provided by three N atoms of the tridentate Schiff base and two N atoms of μ-NC ions, while the copper(I) centers adopt a trigonal-planar geometry. Three copper centers are interconnected through μ-CN/μ-NC via {-Cu1(L)(μ-NC)2Cu2(μ-CN)Cu3(μ-NC)-} units to form 2-D polymeric ribbons parallel to the b-axis. These 2-D polymeric ribbons in the crystalline state are further stabilized through π···π stacking interactions. Hirshfeld surface analysis was performed to gain additional insight into the interactions responsible for the packing of 1. Variable-temperature magnetic susceptibility studies showed a weak ferromagnetic interaction among the copper centers in 1 through cyanide bridges with J = 1.28 cm−1
Preparation of nano Arsenic(III) sulfide from arsenic(III)-dithiocarbamate precursors: Synthesis, spectral, single crystal X-ray structural, BVS and CSM analysis of tris(disubstituteddithiocarbamato)arsenic(III) complexes
No full textNano As2S3 was prepared solvothermally from three dithiocarbamte precursor complexes [As(chmdtc)3] (1), [As(chedtc)3] (2) and [As(dchdtc)3] (3) (where chmdtc = cyclohexylmethyldithiocarbamate, chedtc = cyclohexylethyldithiocarbamate and dchdtc = dicyclohexyldithiocarbamate). The nano arsenic trisulfide was characterized by PXRD, SEM-EDX, HRTEM-SAED techniques. The arsenic(III) complexes, (1), (2) and (3) were prepared and characterized by electronic, IR, TG/DTA and NMR (1H and 13C) spectra and single crystal X-ray diffraction. Electronic spectra of the complexes show signature bands in the range: 446–451 nm due to charge transfer transitions. Thioureide νC−N bands observed at 1444, 1468 and 1470 cm−1 for (1), (2) and (3) respectively indicate the partial double bonded nature. NMR spectra show that the immediate environment around thioureide nitrogen was largely affected by complex formation. 13C NMR confirmed the presence of thioureide carbon as a weak signal in the range: 197.63–198.32 ppm. The single crystal X-ray structures of [As(chmdtc)3] (1) [As(chedtc)3] (2) and [As(dchdtc)3] (3) indicate that the central atom is in a highly distorted octahedral environment of sulfur atoms due to the presence of lone pair of electrons. Continuous Shape measures of AsS6 cores in the three complexes are 7.5752, 6.2013 and 8.2473 for (1), (2) and (3) respectively confirm the proximate geometry to be octahedral. Complex (3) deviates to the largest extent from the octahedral geometry than the other two because of the largest steric demand of the two cyclohexyl rings. Two sets of As-S distances, shorter ones are in the range: 2.3164(7)–2.3438(8) Å and the longer ones are in the range: 2.841(2)–2.913(2) Å resulting in heteroleptic bonding. As a contrast to [As(chmdtc)3] (1), ethylcyclo- and dicyclo-analogues show non-covalent S—H, C—H and H—H short contacts, which results in supramolecular interactions. BVS calculations with structural data confirmed the formal oxidation state of arsenic as 3.0
Azido derivatives of dinuclear copper(II) and 1D polynuclear nickel(II) complexes containing an unsymmetrical bidentate amine: synthesis, crystalline architecture, and magnetic behavior
No full textDinuclear copper(II) complex [Cu2(L)2(μ2-1,1-N3)2(N3)2] (1) with double μ1,1-azido bridges and polynuclear nickel(II) complex [Ni(L)(μ2-1,1-N3)(μ2-1,3-N3)]n (2) with alternate double μ1,1-azido and μ1,3-azido bridges [L = 1-amino-2-(dimethylamino)ethane, N3− = azide ion] have been synthesized and were characterized by physicochemical and spectroscopic methods. X-ray structural analysis revealed that each Cu(II) center of 1 adopts a distorted square-pyramidal geometry with a CuN5 chromophore ligated through two N atoms of L, two N atoms of double bridging (μ1,1-N3), and one N atom of terminal azide ion. On the other hand, each Ni(II) center around the asymmetric unit of 2 adopts a distorted octahedral geometry with a NiN6 chromophore ligated through two N atoms of L, two N atoms of double μ1,1-N3, and two N atoms of double μ1,3-N3 bridges. The adjacent nickel centers are connected to alternate double μ1,1-N3 and double μ1,3-N3 bridges, affording a one-dimensional (1D) polymeric chain structure. Temperature-dependent magnetic susceptibility measurements evidenced a dominant antiferromagnetic interaction between the metal centers of both complexes 1 and 2
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
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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