1,721,579 research outputs found
An Investigation of Supramolecular Interactions in some Electronically Active Organic and Organometallic Materials
No full textThe opening section of this thesis reviews the application of the concepts of supramolecular chemistry to the control of the solid-state behaviour of organic and organometallic materials. The application of these concepts to our understanding of (i) electronically active salts based on TCNQ and its analogues; and (ii) simple 2,6-disubstituted pyridine derivatives is then reported.Two series of salts have been prepared based on (a) the Mn+ (mnt2-)2) anion and (b) on radialene and triazine analogues of TCNQ.- (TCNQ = 7,7,8,8-tetracyanoquinodimethane). For both these series, counter cations chosen for study were either (i) simple ammonium and pyridinium cations; (ii) cyaninium cations or (iii) ionophore-encapsulated alkali metal cations. Detailed comparison of the solid-state behaviour of these materials has revealed that in addition to electrostatic association, specific C-H......X interactions play an important structure forming role.In a parallel study C-H......X interactions have been found to play a crucial role in the solid-state behaviour of pyridine 2,6-dicarboxylate esters, where a triple interaction of this type leads to the formation of infinite tapes in the solid-state. This contact, a novel supramolecular synthon, is insensitive to the nature of the ester side arms. Preliminary studies on the effect of modifying the nature of this contact are also reported. The analogous pyridine 2,6-dicarboxamides do not show this phenomenon, but prefer a U-shaped conformation which is shown to be ideal for metal ion complexation. In particular 2,6-bis-N,N-(2-pyridylmethyl) pyridine dicarboxamide reacts with nickel (II) and copper (II) to form neutral complexes, which in the latter case are helical. However with cobalt (III) a 2:1 ligand-to-metal complex is formed.</p
Review: Children Living in Sustainable Built Environments: New Urbanisms, New Citizens by Pia Christensen, Sophie Hadfield-Hill, John Horton, Peter Kraftl
No full textReviewed Work: Children Living in Sustainable Built Environments: New Urbanisms, New Citizens by Pia Christensen, Sophie Hadfield-Hill, John Horton, Peter Kraft
Metallocene to metallocene conversion. Synthesis of an oxazoline-substituted pentamethyliridocenium cation from a ferrocenyloxazoline
Full text linkReaction of (S)-2-ferrocenyl-4-(1-methylethyl)oxazoline with [Cp*IrCl2]2 in benzonitrile with KPF6 and NaOH gave (?5-(S)-2-(4-(1-methylethyl))oxazolinylcyclopentadienyl)(?5-pentamethylcyclopentadienyl)iridium(III) hexafluorophosphate (68%). This transformation of an iron-based into an iridium-based metallocene proceeds via the rearrangement, with loss of cyclopentadienyliron, of an intermediate cationic ferrocenyliridacycle
Single crystal diffraction raw data for Fampridine hydrochloride Phase 1
No full textA set of diffraction images (in both Denzo .x and Bruker Nonius .kcd formats) collected on a Bruker Nonius KappaCCD diffractometer on an FR591 rotating anode generator equipped with confocal mirrors. The sample is Phase 1 of the Fampridine hydrochloride organic salt - a system that forms numerous complicated phases. The authors wish to make the raw data available so that those who wish to explore the modelling of these exceptionally complex systems may process the data themselves.</span
Binding of Co3+ and CoCl42- within a pyridine-cored molecular cleft
No full textWhen the novel pyridine-2,6-dicarboxylic acid bis[(quinolin-8-ylmethyl)amide] (PDQA) is treated with CoCl2 a 1:1 complex [(PDQAH(2))][(COCl4)-Cl-II] (2), is formed. Treatment of 2 with NaNO2 results in oxidation of the CoCl42- to Co-III affording [(PDQA-H)Co-III(NO2)(2)] (3) whereas under basic conditions a 2:1 (ligand:Co-III) paddle-like structure [Co-III(PDPA-2H)(2)K(H2O)(2)(CH3 OH)(1)](H2O)(2) (1) is obtained
On the self assembly of a trans-dibromo-bis-(dppfo<sub>2</sub>) iron (III), a ferrocene-ligand complex, dppfo<sub>2</sub> = [(ƞ<sup>5</sup>-C<sub>5</sub>H<sub>4</sub>P(O)Ph<sub>2</sub>)<sub>2</sub>Fe]: Letting nature do the work
No full textThe octahedral iron complex trans-[{O,O-(ƞ5-C5H4P(O)Ph2)2Fe}2Fe(III)Br2][Fe(III)Br4]has been prepared by self-assembly simply by adding anhydrous ferric chloride to a dichloromethane/methanol solution of dppf and 1,1,2,2-tetrabromoethane and then leaving to form a complex slowly. The key factor in the self-assembly is the addition of 1,1,2,2-tetrabromoethane which is the source of the bromide and is responsible for acid catalysed hydrolysis of ferric chloride.</p
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
Single crystal diffraction raw data for Fampridine hydrochloride Phase 2
No full textA set of diffraction images in Rigaku Oxford Diffraction (img) format, collected on a Rigaku FRE+ diffractometer, equipped with HF Varimax confocal mirrors and an AFC12 goniometer and HG Saturn 724+ detector diffractometer. The sample is Phase 2 of the Fampridine hydrochloride organic salt - a system that forms numerous complicated phases. The authors wish to make the raw data available so that those who wish to explore the modelling of these exceptionally complex systems may process the data themselves.</span
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