| 1. |
- Gustafsson, Björn, 1970, et al.
(author)
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Complexes between copper(I) halides and 1,2-phenylenediamine
- 2005
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In: Inorganica Chimica Acta. - : Elsevier BV. - 0020-1693. ; 358, s. 1327-1330
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Journal article (peer-reviewed)abstract
- Two copper(I) compounds containing 1,2-phenylenediamine have been prepared and characterised by means of crystal structure determination. The compounds catena-μ-1,2-phenylenediamine(acetonitrile)chlorocopper(I) (1) and catena-μ-1,2-phenylenediamine(acetonitrile)bromocopper(I) (2) are isostructural, bridging to form polymeric chains being effected solely by the aromatic amine and not by halide. Copper(I) exhibits distorted tetrahedral coordination geometry in both complexes. The chains are interconnected to form layers through short intermolecular XH interactions of 2.32.6 , involving amine hydrogen atoms and the terminal chloride or bromide bonded to copper(I). Neither compound is prone to decomposition by loss of the acetonitrile ligand, the reason for this being apparent from inspection of their crystal structures.
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| 2. |
- Holmqvist, Kenneth, et al.
(author)
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Eye tracking : empirical foundations for a minimal reporting guideline
- 2023
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In: Behavior Research Methods. - : Springer Science and Business Media LLC. - 1554-3528. ; 55:1, s. 364-416
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Journal article (peer-reviewed)abstract
- In this paper, we present a review of how the various aspects of any study using an eye tracker (such as the instrument, methodology, environment, participant, etc.) affect the quality of the recorded eye-tracking data and the obtained eye-movement and gaze measures. We take this review to represent the empirical foundation for reporting guidelines of any study involving an eye tracker. We compare this empirical foundation to five existing reporting guidelines and to a database of 207 published eye-tracking studies. We find that reporting guidelines vary substantially and do not match with actual reporting practices. We end by deriving a minimal, flexible reporting guideline based on empirical research (Section "An empirically based minimal reporting guideline").
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| 3. |
- Moberg, Viktor, et al.
(author)
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Efficient Cluster-Based Catalysts for Asymmetric Hydrogenation of α-Unsaturated Carboxylic Acids.
- 2012
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In: Chemistry: A European Journal. - : Wiley. - 1521-3765 .- 0947-6539. ; 18:39, s. 12458-12478
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Journal article (peer-reviewed)abstract
- The new clusters [H(4) Ru(4) (CO)(10) (μ-1,2-P-P)], [H(4) Ru(4) (CO)(10) (1,1-P-P)] and [H(4) Ru(4) (CO)(11) (P-P)] (P-P=chiral diphosphine of the ferrocene-based Josiphos or Walphos ligand families) have been synthesised and characterised. The crystal and molecular structures of eleven clusters reveal that the coordination modes of the diphosphine in the [H(4) Ru(4) (CO)(10) (μ-1,2-P-P)] clusters are different for the Josiphos and the Walphos ligands. The Josiphos ligands bridge a metal-metal bond of the ruthenium tetrahedron in the "conventional" manner, that is, with both phosphine moieties coordinated in equatorial positions relative to a triangular face of the tetrahedron, whereas the phosphine moieties of the Walphos ligands coordinate in one axial and one equatorial position. The differences in the ligand size and the coordination mode between the two types of ligands appear to be reflected in a relative propensity for isomerisation; in solution, the [H(4) Ru(4) (CO)(10) (1,1-Walphos)] clusters isomerise to the corresponding [H(4) Ru(4) (CO)(10) (μ-1,2-Walphos)] clusters, whereas the Josiphos-containing clusters show no tendency to isomerisation in solution. The clusters have been tested as catalysts for asymmetric hydrogenation of four prochiral α-unsaturated carboxylic acids and the prochiral methyl ester (E)-methyl 2-methylbut-2-enoate. High conversion rates (>94 %) and selectivities of product formation were observed for almost all catalysts/catalyst precursors. The observed enantioselectivities were low or nonexistent for the Josiphos-containing clusters and catalyst (cluster) recovery was low, suggesting that cluster fragmentation takes place. On the other hand, excellent conversion rates (99-100 %), product selectivities (99-100 % in most cases) and good enantioselectivities, reaching 90 % enantiomeric excess (ee) in certain cases, were observed for the Walphos-containing clusters, and the clusters could be recovered in good yield after completed catalysis. Results from high-pressure NMR and IR studies, catalyst poisoning tests and comparison of catalytic properties of two [H(4) Ru(4) (CO)(10) (μ-1,2-P-P)] clusters (P-P=Walphos ligands) with the analogous mononuclear catalysts [Ru(P-P)(carboxylato)(2) ] suggest that these clusters may be the active catalytic species, or direct precursors of an active catalytic cluster species.
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