1,720,955 research outputs found
Preparation and photophysical studies of copper(I) and ruthenium(II) complexes of 4,4′-bis(3,5-dimethoxyphenyl)-6,6′-dimethyl-2,2′-bipyridine
No full textWe report the synthesis of a new ligand, 4,4'-bis(3,5-dimethoxyphenyl)-6,6'-dimethyl-2,2'-bipyridine, optimised for binding to copper(I) and with pendant functionality that can eventually be developed into metallodendritic structures. The synthesis and photophysical properties of complexes with copper(I) and ruthenium(II) are reported. The solid state structure of the complex [Cu(1)(2)][PF6] center dot MeCN (1 = 4,4'-bis(3,5-dimethoxyphenyl)- 6,6'-dimethyl-2,2'-bipyridine) is also described. (C) 2008 Elsevier B. V. All rights reserved
Supramolecular photochemistry of new ruthenium(II) oligopyridine complexes: from design to light conversion
Full text linkPhotochemistry is a natural phenomenon, which began at the origin of the universe and the
world and also a modern science which describes the interaction between light and matter in
several main science domains, such as chemistry, physics and biology. Photochemistry plays
a fundamental role in life (photosynthesis, vision, phototaxis, etc…) and also in technology
(image reproduction, photocatalysis, photodegradation, etc…). The last 30 years of
photochemistry have shown the fundamental role played in experiment and theoretical
investigations. From determination of molecular mechanisms to photocatalysis and electronic
information of complex devices, studying photochemistry is now indispensable. The
photochemical and photophysical processes of thousands of organic and organometallic,
coordination compounds complexes have been studied and elucidated, and now confirmed
with the help of theoretical tools to explain the structural, energetic and dynamic properties
of the molecules in their most important excited state. The major part of photochemical
investigations were focused on molecular species with simple processes (molecular
photochemistry).
The combination of atoms leads to molecules and the combination of molecular components
leads to supramolecular species. Current chemical research shows us that photons and energy
information can be used in supramolecular species. The interest in the chemistry of the
interaction of supramolecular species with light is great because its allows several types of
properties not previously observed. In the last few year supramolecular photochemistry has
taken an important part in chemistry. Photochemistry and supramolecular photochemistry are
interdisciplinary areas.
In this introduction we will show the meaning of supramolecular chemistry and also define
some fundamental concepts of photochemistry, and the host-guest theory and explain some
recent investigations oligopyridine chemistry .
This work shows the design of new ruthenium (II) oligopyridine complexes and their
photophysical and electrochemical properties.
Chapter I highlights some recent developments of those topics in chemistry and especially in
supramolecular systems.
Chapter II describes the synthesis via Suzuki-coupling of the in the 4-methoxyphenyl, 3,5-
dimethoxy and 1-naphthyl substitution of 4,4´ position of 2,2´-bipyridine. The corresponding
Ru(II) complexes have been prepared.
Chapter III deals with the synthesis of new starshaped X and Y metallodendrimers , the
synthesis of 4’-substitued tpy ligands their complexation with Ru(II), and the synthesis of
polynuclear supramolecular assemblies.
Chapter IV concerns the photophysical and electrochemical properties of some chapter II and
III complexes Ru(II), determination of luminescence lifetimes and quantum yields.
Chapter V decribes the synthesis of 6,6´-dimethyl-4,4´-(3,5-dimethoxyphenyl)-2,2´-bipyridine
ligand, its complexation with Cu(I) and Ru(II) and their photophysical and electrochemical
properties.
Chapter VI shows the synthesis of 1-pyrenyl substituted tpy ligand and its complexation with
Ru(II), Os(II) and Ir(III) as potent donors and acceptors for the formation of polyads.
Chapter VII concerns the synthesis of narrow band gap spacer with non-classical p electron
ring spacer. The synthesis of 4,7-trimethylsilylacetylenyl-3,1,2-benzothiadiazole and 6,13
derivate of pentacene as potent new spacers for polymetallic rod-like systems
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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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