| 1. |
- Almesåker, Ann, et al.
(författare)
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Coordination chemistry of N,N,4-tris(pyridin-2-ylmethyl)aniline, a novel flexible, multimodal ligand
- 2007
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Ingår i: CrystEngComm. - : Royal Society of Chemistry (RSC). - 1466-8033. ; 9:11, s. 997-1010
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Tidskriftsartikel (refereegranskat)abstract
- The ligand N, N, 4-tris(pyridin-2-ylmethyl) aniline was synthethised using a multicomponent reaction, which is applicable to the synthesis of a large library of similarly structured ligands. A range of metal complexes with copper, cobalt and manganese ions were crystallised as discrete complexes, dimers and 1D coordination polymers, illustrating the flexibility of the ligand in the preparation of diverse structures. While coordination about the metal centres is similar in each group with a common metal ion, the different structures represent materials with varying structural and packing topologies. Varying the counterions and crystallisation solvents gives rise to discrete complexes, dimers and a porous 1D coordination polymer. In the latter case, solvent molecules entrapped in the channels are replaceable and guest exchange is detected by single crystal and powder diffraction indicating interesting storage possibilities.
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| 2. |
- Almesåker, Ann, et al.
(författare)
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One-pot synthesis of tripodal tris(2-aminoethyl)amine derivatives from seven molecular components
- 2009
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Ingår i: Tetrahedron Letters. - : Elsevier BV. - 0040-4039 .- 1359-8562. ; 50:16, s. 1847-1850
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Tidskriftsartikel (refereegranskat)abstract
- Complex tripodal tris(2-aminoethyl)amine (tren)-based ligands have been prepared in a single-pot reaction of tren with 3 equiv each of cyclohexenone and a benzaldehyde derivative (i.e., from seven components and three molecular types). The highest yield of product was obtained for p-nitrobenzaldehyde, the most electrophilic aldehyde used. (C) 2009 Published by Elsevier Ltd.
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| 3. |
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| 4. |
- Boija, Susanne, et al.
(författare)
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Determination of conditional stability constants for some divalent transition metal ion-EDTA complexes by electrospray ionization mass spectrometry
- 2014
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Ingår i: Journal of Mass Spectrometry. - : Wiley. - 1076-5174 .- 1096-9888. ; 49:7, s. 550-556
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Tidskriftsartikel (refereegranskat)abstract
- Conditional stability constants of coordination complexes comprising divalent transition metals, Cu2+, Ni2+, Zn2+, Co2+, and ethylenediaminetetraacetic acid (EDTA) were determined utilizing electrospray ionization mass spectrometry. The deviation of signal response of a reference complex was monitored at addition of a second metal ion. The conditional stability constant for the competing metal was then determined through solution equilibria equations. The method showed to be applicable to a system where Co2+ and Zn2+ competed for EDTA at pH 5. When Cu2+ and Ni2+ competed for EDTA, the equilibrium changed over time. This change was shown to be affected in rate and size by the type of organic solvent added. In this work, 30% of either methanol or acetonitrile was used. It was found that if calibration curves are prepared for both metal complexes in solution and the measurements are repeated with sufficient time space, any change in equilibrium of sample solutions will be discovered. Copyright © 2014 John Wiley & Sons, Ltd. Copyright © 2014 John Wiley & Sons, Ltd.
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| 5. |
- Hidestål, Olle, et al.
(författare)
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A chiral biselectrophile for efficient asymmetric synthesis in water
- 2005
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Ingår i: Green Chemistry. - : Royal Society of Chemistry (RSC). - 1463-9270 .- 1463-9262. ; 7:5, s. 259-261
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Tidskriftsartikel (refereegranskat)abstract
- The development of an efficient asymmetric dihydroxylation of 1,6-dibromodiene afforded a chiral biselectrophilic diol that displayed highly useful reactivity in water, as demonstrated by a three-step, two-pot asymmetric synthesis of a highly functionalized tetrahydrofuran.
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| 6. |
- Petersson, M. J., et al.
(författare)
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Unexpected regiospecific reactivity of a substituted phthalic anhydride
- 2007
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Ingår i: Tetrahedron. - : Elsevier BV. - 0040-4020 .- 1464-5416. ; 63:6, s. 1395-1401
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Tidskriftsartikel (refereegranskat)abstract
- Regioselective nucleophilic addition at C1 of anhydride 7 by a range of nucleophiles occurs to produce amide, ester and thioester derivatives 8-15 (60-99%). The increased electrophilic reactivity of the C I carbonyl group of anhydride 7 is supported by a competition experiment with phthalic anhydride. Unexpected formation of lactams 18 and 19 from amides 12 and 13 was shown to proceed via the lactamols 16 and 17 and could be controlled by the reaction conditions. The solid-state structure of 19 is reported. (c) 2006 Published by Elsevier Ltd.
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| 7. |
- Scott, J. L., et al.
(författare)
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Guest signaling compound: trans-3,3 '-bis(diphenylhydroxymethyl)azobenzene
- 2007
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Ingår i: Crystal Growth & Design. - : American Chemical Society (ACS). - 1528-7483 .- 1528-7505. ; 7:6, s. 1049-1054
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Tidskriftsartikel (refereegranskat)abstract
- A chromogenic azobenzene compound, (E)-(3,3'-(diazene-1,2-diyl)bis(3,1-phenylene))bis(diphenylmethanol), forms lattice inclusion compounds with a range of common solvents. It is yellow in the unsolvated crystalline form, but orange or orange-red when crystallized as solvates with guest molecules that contain hydrogen-bond acceptors. Close examination of crystal structures of unsolvated and solvated forms reveals that differences in hydrogen bonding and a change in conformation of the azobenzene core are responsible for the change in lambda of absorption of the chromophore and hence color of the crystals. Hirshfeld surfaces and fingerprint plots reveal subtle differences in intermolecular interactions in the solvated and unsolvated crystalline forms.
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| 8. |
- Svanedal, Ida, 1979-, et al.
(författare)
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Metal Ion Coordination, Conditional Stability Constants and Solution Behavior of Chelating Surfactant Metal Complexes
- 2014
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Ingår i: Langmuir. - : American Chemical Society (ACS). - 0743-7463 .- 1520-5827. ; 30:16, s. 4605-4612
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Tidskriftsartikel (refereegranskat)abstract
- Coordination complexes of some divalent metal ions with the DTPA (diethylenetriaminepentaacetic acid)-based chelating surfactant 2-dodecyldiethylenetriaminepentaacetic acid (4-C12-DTPA) have been examined in terms of chelation and solution behavior. The headgroup of 4-C 12-DTPA contains eight donor atoms that can participate in the coordination of a metal ion. Conditional stability constants for five transition metal complexes with 4-C12-DTPA were determined by competition measurements between 4-C12-DTPA and DTPA, using electrospray ionization mass spectrometry (ESI-MS). Small differences in the relative strength between the coordination complexes of DTPA and 4-C12-DTPA indicated that the hydrocarbon tail only affected the chelating ability of the headgroup to a limited extent. The coordination of Cu2+ ions was investigated in particular, using UV-visible spectroscopy. By constructing Job's plots, it was found that 4-C12-DTPA could coordinate up to two Cu2+ ions. Surface tension measurements and NMR diffusometry showed that the coordination of metal ions affected the solution behavior of 4-C 12-DTPA, but there were no specific trends between the studied divalent metal complexes. Generally, the effects of the metal ion coordination could be linked to the neutralization of the headgroup charge of 4-C 12-DTPA, and the resulting reduced electrostatic repulsions between adjacent surfactants in micelles and monolayers. The pH vs concentration plots, on the other hand, showed a distinct difference between 4-C12-DTPA complexes of the alkaline earth metals and the transition metals. This was explained by the difference in coordination between the two groups of metal ions, as predicted by the hard and soft acid and base (HSAB) theory.
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| 9. |
- Zasadowski, Dariusz, et al.
(författare)
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Removal of dissolved and colloidal substances from mechanical pulping white waters by flotation
- 2011
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Ingår i: 16th International Symposium on Wood, Fiber and Pulping Chemistry - Proceedings, ISWFPC. - Tianjin : China Light Industry Press. ; , s. 1238-1242
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Various sorts of process water, foaming agents and a new chelating surfactant have been investigated in the chemical optimization of flotation ofwaters generated at laboratory and white water from mechanical pulping. Turbidity measurements, the Orcinol method for quantitative carbohydrate analysis and total organic carbon (TOC) as well as gas chromatography (GC) of extractives, have been carried out to determine theremoval and characteristics of Dissolved and Colloidal substances (DisCo). The tests have been realized under different conditions, such as using different flotation cells, foaming agents and complexing agents at different temperatures and pH values. It was found that a reduction of thewhite water turbidity of 70% and a 50% removal of the lipophilic substances from the white water can be obtained in a single-stage flotationunit, and that the selection of suitable flotation equipment, foaming agents and solution conditions plays a very important role in the removalcapacity of the unwished substances.
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