| 1. |
- Abbasi, Alireza, et al.
(författare)
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Highly hydrated cations : Deficiency, mobility and coordination of water in crystalline nonahydrated scandium(III), yttrium(III) and lanthanoid(III) trifluoromethanesulfonate
- 2005
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Ingår i: Chemistry - A European Journal. - : Wiley. - 0947-6539 .- 1521-3765. ; 11:14, s. 4065-4077
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Tidskriftsartikel (refereegranskat)abstract
- Trivalent lanthanide-like metal ions coordinate nine water oxygen atoms, which form a tricapped trigonal prism in a large number of crystalline hydrates. Water deficiency, randomly distributed over the capping positions, was found for the smallest metal ions in the isomorphous nonahydrated trifluoromethanesulfonates, [M(H2O)(n)]CF3SO3)(3), in which M=Sc-III, Lu-III, Yb-III, Tm-III or Er-III. The hydration number n increases (n=8.0(1), 8.4(1), 8.7(1), 8.8(1) and 8.96(5), respectively) with increasing ionic size. Deuterium (H-2) solid-state NMR spectroscopy revealed fast positional exchange between the coordinated capping and prism water molecules; this exchange started at temperatures higher than about 280 K for lutetium(m) and below 268 K for scandium(m). Similar positional exchange for the fully nonahydrated yttrium(m) and lanthanum(m) compounds started at higher temperatures, over about 330 and 360 K, respectively. An exchange mechanism is proposed that can exchange equatorial and capping water molecules within the restrictions of the crystal lattice, even for fully hydrated lanthanoid(III) ions. Phase transitions occurred for all the water-deficient compounds at; 185 K. The hydrated scandium(III) trifluoromethanesulfonate transforms reversibly (Delta H degrees= -0.80(1) kJ mol(-1) on cooling) to a trigonal unit cell that is almost nine times larger, with the scandium ion surrounded by seven fully occupied and two partly occupied oxygen atom positions in a distorted capped trigonal prism. The hydrogen bonding to the trifluoromethanesulfonate anions stabilises the trigonal prism of water ligands, even for the crowded hydration sphere of the smallest metal ions in the series. Implications for the Lewis acid catalytic activity of the hydrated scandium(III) and lanthanoid(III) trifluoromethanesulfonates for organic syntheses performed in aqueous media are discussed.
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| 2. |
- Brouwer, Sophie, et al.
(författare)
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Visualising the ionome in resistant and susceptible plant-pathogen interactions
- 2021
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Ingår i: Plant Journal. - : Wiley. - 0960-7412 .- 1365-313X. ; 108, s. 870-885
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Tidskriftsartikel (refereegranskat)abstract
- At the morphological and anatomical levels, the ionome, or the elemental composition of an organism, is an understudied area of plant biology. In particular, the ionomic responses of plant-pathogen interactions are scarcely described, and there are no studies on immune reactions. In this study we explored two X-ray fluorescence (XRF)-based ionome visualisation methods (benchtop- and synchrotron-based micro-XRF [mu XRF]), as well as the quantitative inductively coupled plasma optical emission spectroscopy (ICP-OES) method, to investigate the changes that occur in the ionome of compatible and incompatible plant-pathogen interactions. We utilised the agronomically important and comprehensively studied interaction between potato (Solanum tuberosum) and the late blight oomycete pathogen Phytophthora infestans as an example. We used one late blight-susceptible potato cultivar and two resistant transgenic plant lines (only differing from the susceptible cultivar in one or three resistance genes) both in control and P. infestans-inoculated conditions. In the lesions from the compatible interaction, we observed rearrangements of several elements, including a decrease of the mobile macronutrient potassium (K) and an increase in iron (Fe) and manganese (Mn), compared with the tissue outside the lesion. Interestingly, we observed distinctly different distribution patterns of accumulation at the site of inoculation in the resistant lines for calcium (Ca), magnesium (Mg), Mn and silicon (Si) compared to the susceptible cultivar. The results reveal different ionomes in diseased plants compared to resistant plants. Our results demonstrate a technical advance and pave the way for deeper studies of the plant-pathogen ionome in the future.
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| 3. |
- Damian Risberg, Emiliana, et al.
(författare)
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Ambidentate dimethyl sulfoxide coordination in protonated dimethyl sulfoxide, (CH3)2SO-H+, and in dichlorobis(dimethyl sulfoxide) palladium(II) and platinum(II) solid solvates, by vibrational and sulfur K-edge X-ray absorption spectroscopy
- 2008
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Ingår i: Dalton Transactions.
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Tidskriftsartikel (refereegranskat)abstract
- The protonated dimethyl sulfoxide cation (CH3)2SO-H+ formed in concentrated hydrochloric acid displays a new low energy feature in its sulfur K-edge X-ray absorption near edge structure (XANES) spectrum. Density Functional Theory – Transition Potential (DFT-TP) calculations reveal that the energy of the transition S(1s) LUMO, which has antibonding *(S-O) character, has decreased about 0.8 eV. Normal coordinate force field analyses of the vibrational spectra show that the SO stretching force constant of the oxygen-coordinated (CH3)2SO-H+ species has decreased to 3.73 N cm-1 from 4.72 N cm-1 in neat liquid dimethyl sulfoxide. The effects of sulfur coordination on the ambidentate dimethyl sulfoxide molecule were investigated for the trans-Pd((CH3)2SO)2Cl2 and cis-Pt((CH3)2SO)2Cl2 complexes with square planar coordination of the chlorine and sulfur atoms. The XANES spectra again showed shifts toward low energy of the transition S(1s) LUMO, now with antibonding *(M-Cl, M-S) character, with a larger shift for M = Pt than Pd. DFT-TP calculations indicated that the differences between the XANES spectra of the geometrical isomers of the M((CH3)2SO)2Cl2 complexes are expected to be too small to allow experimental distinction. The vibrational spectra of the palladium(II) and platinum(II) complexes were recorded and complete assignments of the fundamentals were achieved. Even though the M-S bond distances are quite similar the high covalency especially of the Pt-S bonds induces significant increases in the S-O stretching force constants, 6.79 and 7.18 N cm-1, respectively.
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| 4. |
- Lindqvist-Reis, Patric
(författare)
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Structure of solvated matal ions
- 2000
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The structure of the solvated group 3 ions scandium(III),yttrium(III) and lanthanum(III), has been determined in aqueoussolution and in some oxygen donor solvents, and compared withthe hydrated group 13 ions gallium(III) and indium(III). Acombination of X-ray absorption fine structure (XAFS), largeangle X-ray scattering (LAXS), crystallography and vibrationspectroscopy has been used for the structure studies of thehydrated ions and their dimethylsulfoxide andN,N´-dimethylpropylene urea solvates in solution and inthe solid state. For the hexahydrated gallium(III) andindium(III) ions in solution, the metal-oxygen distances werefound to be 1.959(6) Å and 2.131(7) Å to the firsthydration shell, and 4.05(1) and4.13(1) Å, respectively,to fairly well-defined second hydration shells containing abouttwelve water molecules. The hydration structure of thecalcium(II) ion was studied by combining EXAFS and LAXS studiesand Molecular Dynamics simulations. The biochemically importantcalcium ion was found to be octahydrated in aqueous solutionwith abroad and asymmetric distribution of the Ca-O bonddistances around the mean value 2.46(1) Å. Also theyttrium(III) ion was found to be octahydrated in aqueoussolution with an asymmetric distribution of the Y-O bonddistances around a mean value of 2.366(5) Å. The mean Y-Odistance in the eight-coordinated compound([(H2O)4Y(µ-OSO2CH3)2]CH3SO3)nis 2.35 Å. The hydration of thelanthanum(III) ion was consistent with a coordination of ninewater molecules with the La-O distances 6´2.52(2) and3´2.65(3) Å, probably with the oxygen atoms forming atricapped trigonal prism. Also for the hydrated scandium(III)ion in aqueous solution, a capped trigonal prismaticcoordination figure, with the mean Sc-O bond distance 2.17(1)Å to the water molecules in the prism, gives the bestdescription of the structure. There seems to be 2 or 3 cappingwater molecules, but the Sc-O distances in the range 2.3-2.5Å are not well-defined. The crystal structure of [Sc(H2O)8](CF3SO3)3, which at ambient temperature is isomorphous withthe [M(H2O)9](CF3SO3)3compounds with a series of nonahydrated tricappedtrigonal prismatic lanthanide(III) ions, was studied attemperatures down to 100 K. One capping water molecule wasfound to be missing in the[Sc(H2O)8](CF3SO3)3structure, causing a displacement of the scandiumionabout 0.2 Å from the centre of the trigonal prism. Aredetermination of the isomorphous[Yb(H2O)n](CF3SO3)3structure was made, resulting in n » 8.6 forthe slightly larger Yb(III) ion. Octahedrally coordinatedscandium(III) ions were found in the crystal structures of[Sc(H2O)6][Sc(CH3SO3)6]and trans-[Sc(H2O)4Cl2]Cl×2H2O, with mean Sc-O distances of 2.08 and 2.11Å, respectively. The scandium(III) ion was found to beoctahedrally six-coordinated in dimethylsulfoxide solution,with the mean Sc-O distance 2.09 Å, and in the solid[Sc(dmso)6]I3 compound with Sc-O 2.075(3) Å. The largeryttrium(III) ion is eight-coordinated in solution with the meanY-O distance 2.36(1) Å. In the crystal structure of[Y(dmso)8]I3 the mean Y-O distance is 2.36 Å, while theY-O distance to the two dimethylsulfoxide ligands in [Y(H2O)6(dmso)2]Cl3is only 2.27 Å and the mean Y-O waterdistance 2.37 Å. Also lanthanum(III) in dimethylsulfoxidesolution was found to form an eight-coordinated complex withthe mean La-O distance 2.50(2) Å. TheN,N´-dimethylpropylene urea solvated scandium(III),yttrium(III) and lanthanum(III) ions were found to have thecoordination number six, six and seven in solution,respectively, showing that steric ligand-ligand repulsioneffects are controlling the solvation numbers in aproticsolvents for these ions with noble gas electronconfiguration.
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| 5. |
- Lundberg, Daniel, et al.
(författare)
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Coordination chemistry effects of the space-demanding solvent molecule N,N′-dimethylpropyleneurea
- 2024
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Ingår i: Dalton Transactions. - 1477-9226 .- 1477-9234. ; 53:4, s. 1817-1832
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Tidskriftsartikel (refereegranskat)abstract
- Crystallographic investigations of eight homoleptic N,N '-dimethylpropyleneurea (dmpu) coordinated metal ions in the solid state, [Mg(dmpu)(5)]I-2 (1), [Ca(dmpu)(6)]I-2 (2), [Ca(dmpu)(6)](ClO4)(2) (3), [Ca(dmpu)(6)](CF3SO3)(2) (4), [Sr(dmpu)(6)](CF3SO3)(2) (5), [Ba(dmpu)(6)](CF3SO3)(2) (6), [Sc(dmpu)(6)]I-3 (7), and [Pr(dmpu)(6)]I(I-3)(2) (8), and the complex [CoBr2(dmpu)(2)] (9) as well as the structures of the dmpu coordinated calcium, strontium, barium, scandium(III) and cobalt(II) ions and the cobalt(II) bromide complex in dmpu solution as determined by EXAFS are reported. The methyl groups in the dmpu molecule are close to the oxygen donor atom, causing steric restrictions, and making dmpu space-demanding at coordination to metal ions. The large volume required by the dmpu ligand at coordination contributes to crowdedness around the metal ion with often lower coordination numbers than for oxygen donor ligands without such steric restrictions. The crowdedness is seen in M & ctdot;H distances equal to or close to the sum of the van der Waals radii. To counteract the space-demand at coordination, the dmpu molecule has an unusual ability to increase the M-O-C bond angle to facilitate as large coordination numbers as possible. M-O-C bond angles in the range of 125-170 degrees are reported depending on the crowdedness caused by the coordination figure and the M-O bond distance. All reported structures of dmpu coordinated metal ions in both the solid state and dmpu solution are summarized to study the relationship between the M-O-C bond angle and the crowdedness around the metal ion. However, highly symmetric complexes seem to be favoured in the solid state due to favourable lattice energies. As a result, the dmpu coordinated lanthanoid(III) ions are octahedral in the solid state, while they, except lutetium, are seven-coordinate in the dmpu solution.
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| 6. |
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| 7. |
- Persson, Ingmar, et al.
(författare)
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An EXAFS Spectroscopic, Large Angle X-Ray Scattering and Crystallo¬graphic Study of the Hexahydrated and the Dimethyl Sulfoxide and Pyridine-1-Oxide Hexasolvated Mercury(II) Ions
- 2008
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Ingår i: Chemistry, A European Journal. ; 14, s. 6687-6696
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- The structure of the solvated mercury(II) ion in aqueous and dimethyl sulfoxide solution has been studied by means of large angle X-ray scattering (LAXS) and EXAFS tech¬niques. The distribution of the Hg-O bond distances is unusually wide and asymmetric in both solvents. In aqueous solution hexahydrated [Hg(OH2)6]2+ ions in distorted octahedral configuration, with the centroid of the Hg-O bond distances at 2.38(1) Å, are surrounded by a diffuse second hydration sphere, with HgOII distances around a mean value of 4.20(2) Å. In dimethyl sulfoxide solution the six Hg-O and HgS distances of the hexasolvated Hg(OS(CH3)2)6]2+ complex are centered around 2.38(1) and 3.45(2) Å, respectively. The crystal structure of hexakis¬(pyridine-1-oxide)mercury(II) perchlorate has been re-determi¬ned at 100 K. The space group R implies six equal Hg-O bond distances of 2.3416(7) Å for the Hg(ONC5H5)62+ complex, as also for the hexaaquamercury(II) perchlorate and hexakis(dimethyl sulfoxide)mercury(II) trifluoro¬methanesulfonate compounds, according to previous crystallographic results. However, EXAFS results for those compounds in all cases reveal strongly asymmetric Hg-O bond distance distributions. Vibronic coupling of close valence states in a so-called Pseudo Jahn-Teller Effect probably induces the distorted configurations.
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| 8. |
- Persson, Ingmar, et al.
(författare)
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An EXAFS Spectroscopic, Large-Angle X-Ray Scattering, and Crystallographic Study of Hexahydrated, Dimethyl Sulfoxide and Pyridine 1-Oxide Hexasolvated Mercury(II) Ions
- 2008
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Ingår i: Chemistry - A European Journal. - : Wiley-VCH Verlagsgesellschaft. - 0947-6539 .- 1521-3765. ; 14:22, s. 6687-6696
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Tidskriftsartikel (refereegranskat)abstract
- The structure of the solvated mercury(II) ion in water and dimethyl sulfoxide has been studied by means of large‐angle X‐ray scattering (LAXS) and extended X‐ray absorption fine structure (EXAFS) techniques. The distribution of the HgO distances is unusually wide and asymmetric in both solvents. In aqueous solution, hexahydrated [Hg(OH2)6]2+ ions in a distorted octahedral configuration, with the centroid of the HgO distance at 2.38(1) Å, are surrounded by a diffuse second hydration sphere with Hg⋅⋅⋅OII distances of 4.20(2) Å. In dimethyl sulfoxide, the six HgO and Hg⋅⋅⋅S distances of the hexasolvated [Hg{OS(CH3)2}6]2+ complex are centered around 2.38(1) and 3.45(2) Å, respectively. The crystal structure of hexakis(pyridine 1‐oxide)mercury(II) perchlorate has been redetermined. The space group R implies six equal HgO distances of 2.3416(7) Å for the [Hg(ONC5H5)6]2+ complex at 100 K. However, EXAFS studies of this compound, and of the solids hexaaquamercury(II) perchlorate and hexakis(dimethyl sulfoxide)mercury(II) trifluoromethanesulfonate, also with six equidistant HgO bonds according to crystallographic results, reveal in all cases strongly asymmetric HgO distance distributions. Vibronic coupling of valence states in a so‐called pseudo‐Jahn–Teller effect probably induces the distorted configurations.
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| 9. |
- Risberg, Emiliana Damian, et al.
(författare)
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Ambidentate coordination in hydrogen bonded dimethyl sulfoxide, (CH3)2SO H3O+, and in dichlorobis(dimethyl sulfoxide) palladium(II) and platinum(II) solid solvates, by vibrational and sulfur K-edge X-ray absorption spectroscopy
- 2009
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Ingår i: Dalton Transactions. - : Royal Society of Chemistry (RSC). - 1477-9226 .- 1477-9234. ; , s. 1328-1339
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Tidskriftsartikel (refereegranskat)abstract
- The strongly hydrogen bonded species (CH3)2SOH3O+ formed in concentrated hydrochloric acid displays a new low energy feature in its sulfur K-edge X-ray absorption near edge structure (XANES) spectrum. Density Functional Theory-Transition Potential (DFT-TP) calculations reveal that the strong hydrogen bonding decreases the energy of the transition S(1s) → LUMO, which has antibonding σ*(S–O) character, with about 0.8 eV. Normal coordinate force field analyses of the vibrational spectra show that the SO stretching force constant decreases from 4.72 N cm−1 in neat liquid dimethyl sulfoxide to 3.73 N cm−1 for the hydrogen bonded (CH3)2SOH3O+ species. The effects of sulfur coordination on the ambidentate dimethyl sulfoxide molecule were investigated for the trans-Pd((CH3)2SO)2Cl2, trans-Pd((CD3)2SO)2Cl2 and cis-Pt((CH3)2SO)2Cl2 complexes with square planar coordination of the chlorine and sulfur atoms. The XANES spectra again showed shifts toward low energy for the transition S(1 s) → LUMO, now with antibonding σ*(M–Cl, M–S) character, with a larger shift for M = Pt than Pd. DFT-TP calculations indicated that the differences between the XANES spectra of the geometrical cis and trans isomers of the M((CH3)2SO)2Cl2 complexes are expected to be too small to allow experimental distinction. The vibrational spectra of the palladium(II) and platinum(II) complexes were recorded and complete assignments of the fundamentals were achieved. Even though the M–S bond distances are quite similar the high covalency especially of the Pt–S bonds induces significant increases in the S–O stretching force constants, 6.79 and 7.18 N cm−1, respectively.
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| 10. |
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