479 research outputs found
An introduction to anion receptors based on organic frameworks
No full textThis review article provides a broad overview to the area of anion coordination by synthetic organic receptors and includes examples of different functional groups used to bind anions. The first section examines neutral anion receptors containing amide-, sulfonamide-, urea- and thiourea-based receptors. Then aromatics such as pyrrole, carbazole and indole are discussed before concluding the discussion of neutral systems with examples of hydroxy OH donors. A brief overview of charged systems is also provided
Interactions of organic halide and nitrate salts with meso-octamethylcalix[4]pyrrole
No full textProton NMR titrations have been performed with meso-octamethylcalix[4]pyrrole and a variety of organic chloride and bromide salts in dichloromethane-d2. The results show apparently increasing chloride stability constants within each set of anion salts (tetrabutylammonium < imidazolium < pyridinium). Addition of 1-ethyl-3-methylimidaolium (EMIM) nitrate to dichloromethane-d2 solutions of calix[4]pyrrole caused significantly larger downfield shifts of the pyrrole NH protons of calix[4]pyrrole than addition of equimolar quantities of tetrabutylammonium nitrate. The first crystal structure of a nitrate complex of a calix[4]pyrrole is also presented
Anion binding vs. sulfonamide deprotonation in functionalised ureas
No full textSulfonamide groups, commonly used as neutral hydrogen bond donors in a wide variety of anion receptors, deprotonate upon addition of certain basic anionic guests in two simple functionalised ureas
The construction of Karen Karnak: The multi-author-function
No full textThis thesis is situated within the comparatively recent developments of Web 2.0 and the emergence of interactive WikiMedia, and explores the mode of authorship within a Read/Write culture compared to that of a Read/Only tradition. The hypothesis of this study is that the role of the audience has become merged with the author, and as such, represents new functions and attributes, distinct from a more conventional concept of authorship, in which the roles of audience and author are more separate. Read/Write and participatory culture, as defined by this study, is focused on collaboration, and includes the influences of D.I.Y. culture, Open-Source practices and the production of text by multiple authors. Multi-authorship presents a re-thinking of several concepts which support the notion of the individual author, since the focus of multi-authorship is not on attribution and ownership of a finished text, but on the continued malleability of a text. Modes of multi-authorship, demonstrated in the use of the pseudonyms Alan Smithee and Karen Eliot, represent declarative authors whose names signify multiple origins, whilst concurrently indicating a distinct body of work. The function of these names form an important context to this study, since primary research involves the construction of an experimental mode of multi-authorship utilising WikiMedia technology and the interaction of thirty nine participants, who are invited to create a body of work under the collective pseudonym Karen Karnak. The data generated by this experiment is analysed using aspects of Michel Foucault's author-function to identify and determine power structures inherent in the WikiMedia context. The interplay of power structures, including concepts such as identity, ownership and the body of work, affect the resulting mode of authorship and contribute to the construction of Karen Karnak, suggesting further areas of research into the emerging multi-author
Anion-induced conformational changes in 2,7-disubstituted indole-based receptors
No full textThe conformational preorganization and anion-induced conformational changes of indole-based receptors functionalized with an amide group at the 2-position and a variety of amide, urea and thiourea moieties at the 7-position have been studied by the means of NMR spectroscopy. NOE experiments showed that anti–anti orientation across C2–C2 and C7–N7 bonds is preferred for receptors 1–4 in acetone solution in the absence of anions. Anion–receptor interactions have been evaluated through 1H and 15N chemical shift changes. In 2,7-bis-carboxamido functionalized indoles the interaction with chloride and bromide anions primarily occurs at the indole H1 proton. The introduction of urea and thiourea moieties increases the number of hydrogen bond donor sites which manifests itself in a distribution of halide–receptor interactions among the H1, H7 and H7 protons. Acetate anions also interact strongly with indole and urea NH donor groups, whereas nitrate anions interact solely with H7 and H7 urea/thiourea protons. NOE enhancements in the presence of anions revealed that anion–receptor complexes favour the syn–syn conformation of the C2 and C7 substituents
Organic salt inclusion: the first crystal structures of anion complexes of N-confused calix[4] pyrrole
No full textThe first crystal structures of anion complexes of N-confused calix[4]pyrrole are presented showing chloride binding to the three unconfused pyrrole NH groups and imidazolium inclusion in the calixpyrrole cup
2,7-functionalized indoles as receptors for anions
No full textA series of 2,7-functionalized indoles have been synthesized with appended amide and/or urea or thiourea groups. Anion complexation studies show a marked difference in the mode of interaction of carboxylates with indole-ureas vs indole-amides
Ionic liquid-calix[4]pyrrole complexes: pyridinium inclusion in the calixpyrrole cup
No full textPyridinium based ionic liquids form complexes with meso-octamethylcalix[4] pyrrole with both the anion and cation binding to the tetrapyrrole macrocycle
Structural diversity in the first metal complexes of 2,5-dicarboxamidopyrroles and 2,5-dicarbothioamidopyrroles
No full textMetal complexes of 2,5-dicarboxamidopyrroles and 2,5-dicarbothioamidopyrroles have been structurally characterised for the first time, complementing the significant amount of work that has been reported for the analogous pyridine ligands. N,N-Bis(3,5-dinitrophenyl)-3,4-diphenyl-1H-pyrrole-2,5-dicarboxamide forms octahedral bis(tridentate) complexes with cobalt(III) and nickel(II), where the ligands are bound to the metal centres through deprotonated pyrrole and amide N atoms. N,N-Dibutyl-3,4-diphenyl-1H-pyrrole-2,5-dicarboxthioamide and N,N-diphenyl-3,4-diphenyl-1H-pyrrole-2,5-dicarboxthioamide also form bis(tridentate) cobalt complexes but are only deprotonated at the pyrrole N atom, the remainder of the coordination sphere comprising the thioamide S atoms. The dibutyl derivative was isolated as a Co(II) complex, whereas the diphenyl system deposited a Co(III) complex. In contrast, N,N-dibutyl-3,4-dichloro-1H-pyrrole-2,5-dicarboxamide was found to act as a bidentate ligand, in an octahedral cobalt(II) complex comprising of two bidentate pyrrole ligands, and two aqua ligands. Synthesis of N,N-bis(pyridin-2-ylmethyl)-3,4-diphenyl-1H-pyrrole-2,5-carboxamide gave a pyrrole ligand with increased denticity. Reaction with cobalt(II) chloride resulted in the isolation of a dinuclear helicate complex. The ligand was found to have undergone addition of a methoxy group to one of the linking methylene carbons, presumably as a result of the oxidative addition of solvent methanol
Metaphors of Intellectual Capital of a County
No full textGareth Morgan w swojej przełomowej książce pt. Obrazy organizacji zapoczątkował nowy nurt w myśleniu o organizacjach, nazwany postmodernizmem w zarządzaniu. Chociaż jego prace otworzyły wiele nowych możliwości dla badaczy organizacji, wydaje się, że nie zostały w pełni wykorzystane, szczególnie, jeśli chodzi o badania nad kapitałem intelektualnym. Celem niniejszego opracowania jest choćby częściowe wypełnienie tej luki. Autor zdefiniował 14 metafor kapitału intelektualnego powiatu, stworzonych zgodnie z filozofią zaproponowaną przez G. Morgana. Metafory mają na celu umożliwienie lepszego zrozumienia kapitału intelektualnego w instytucjach publicznych, w tym przypadku w powiatach. Metafory opracowane przez autorów zostały ocenione w trakcie badań empirycznych przez wybranych ekspertów, którzy wyrazili swoje opinie na temat ich trafności opisowej. Jako podsumowanie każda z metafor otrzymywała ocenę odzwierciedlającą jej zdolności do wyjaśniania (subiektywnej) rzeczywistości. Rzeczywistość oczywiście jest rozumiana jako subiektywne odzwierciedlenie poglądów respondentów. Z założenia metafora odnosi się do doświadczeń ludzi, nie do rzeczywistości.Gareth Morgan in his seminal book “Image of Organization” gave birth to a new school of management, which is now called ‘postmodernism in management’. Although it opened up a number of research opportunities, it seems that they have not been fully utilized, especially in the research on intellectual capital. This paper aims to fill this void. The authors proposes a set of 14 metaphors developed according to Gareth Morgan’s school of thought. The metaphors are intended to provide a better understanding of intellectual capital of a public entity, in this case a county. The metaphors developed by the author have been evaluated by experts who expressed their opinions on the quality of the metaphors. During the empirical study each of the metaphors was evaluated as far as its quality is concerned. In conclusion, each of the metaphors is given a rating according to it explanatory value
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