1,721,043 research outputs found
Di- and polynuclear silver(I) derivatives with a new multitopic pyrimidine-base tri-thioether ligand
No full textFour novel silver(I) derivatives containing a new flexible multitopic ligand L, incorporating both the pyrimidine
and the thioether linkages, have been synthesized and characterized. The X-ray crystal structure of the
ligand L shows that two of the three arms of the free ligand adopt an anti geometry about the CH2-S bonds,
while the third one is in a distorted gauche conformation. [(L)Ag(BF4)] and [(L)Ag(PF6)] are insoluble likely
polymeric species, with a cationic network and uncoordinated anions. However, soluble derivatives are
obtained with AgNO3 and AgCF3SO3, where the counter-ions in the solid state are coordinated to the Ag(I)
ion. The X-ray crystal structure of derivative [(L)Ag(NO3)] is composed by dinuclear molecules in which
each L bridges two silver ions through the coordination of the nitrogen atoms of two pyrimidine rings. All
silver(I) derivatives emits bluish-green light with a maximum emission at 517 nm, when excited at 370 nm
source. The quite low emission increases by five times for derivative [(L)Ag(CF3SO3)] on cooling to 50 K
Unsymmetrical Thio-Porphyrazines for NLO: Synthesis, Properties, and Computational Studies
No full textMS.A4.P.15
Complessi Acilpirazolonici di Argento(I) incorporati in Polietilene ad Alta Densita o in Cloruro di Polivinile con Potente Attivita' Antibatterica
No full textSono stati studiati complessi di Ag(I) che contengono leganti 4-acil-5-pirazolonici con differenti caratteristiche elettroniche e steriche, e diversi imidazoli L come leganti ancillari (L = imidazolo (imH); 1-metilimidazolo (Meim); 1-benzilimidazolo (Bzim); 2-etil-imidazolo (2EtimH); 1-benzil-2-metilimidazolo (2Mebzim); di(imidazol-1-il)metanone (COdim); 2,4,6-trimetilpiridina (Me3py); 2-trifluorometilbenzimidazolo (2tfbimH)). La sintesi, caratterizzazione, e struttura cristallina di questi composti è riportata nella seguente invenzione.
È stato trovato che questi composti additivati al polietilene alta densità (HDPE) o polivinilcloruro (PVC) esplicano una potente attività antimicrobica senza rilascio di ioni Ag+. In particolare, specifici test sono stati condotti su derivati additivati ai dischi di polietilene alta densità per verificarne la loro attività antimicrobica verso sospensioni di E. coli, P. aeruginosa e S. aureo
Silver(I) Acylpyrazolonate Complexes embedded in High Density Polyethylene or in polyvinyl chloride with Potent Antibacterial Activity
No full textComposite plastics, containing silver(I) acylpyrazolonate complexes embedded in high density polyethylene or polyvinyl chloride, display potent antibacterial activity by contact, without silver ions release
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
Europium(III) and Terbium(III) Luminescent Lanthanidomesogens
No full textLiquid-crystalline columnar phenanthroline-based ligand, for the first time substituted in 4,7-positions, is synthesized and used to induce low temperature mesomorphism in his corresponding lanthanide complexes. Stable liquid crystalline Eu(III) and Tb(III) complexes with low transition temperatures and low viscosity mesophases are obtained and their thermal and photophysical properties investigated as a function of their different solid, soft and liquid crystalline organisations. The eight-coordination around the metal lanthanide centre is further fulfilled by six oxygen atoms of three bidentate 1-phenyl-3-methyl-4-benzoylpyrazol-5-one proligands
Cyclometalated Pt(IV) trans-diiodo adducts: experimental and computational studies within an homologous series of compounds
No full textFour cyclometalated Pt(iv) compounds, 1a,b and 2a,b, were successfully obtained by oxidative addition of I 2 to 2-phenylpyridinate (PhPy) and Nile Red (NR) derived Pt(ii) complexes with acetylacetonate (acac) or hexafluoroacetylacetonate (hacac) ancillary ligands. Single crystal X-ray diffraction, electrochemical, photophysical and computational studies have been performed in comparison with the analogues Pt(ii) compounds, shedding new light on the role of the oxidation state of the metal centre towards both the luminescence properties and the dioxygen quenchin
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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