| 1. |
- Fahlquist, Henrik, 1983-, et al.
(författare)
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Cs10H[Ga3H8]3 : A Hydrogenous Zintl Phase Containing Propane-Like Polyanions [Ga3H8]3- and Interstitial Hydrogen
- 2013
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Ingår i: Inorganic Chemistry. - : American Chemical Society (ACS). - 0020-1669 .- 1520-510X. ; 52:12, s. 7125-7129
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Tidskriftsartikel (refereegranskat)abstract
- The hydrogenous Zintl-phase Cs10H[Ga3H8](3) containing propane-like polyanions [Ga3H(D)(8)](3-) was successfully synthesized by direct hydrogenation of a 1:1 Cs/Ga metal mixture and characterized by powder X-ray and neutron diffraction. The charge of the polyanions is balanced by two different species of cations, hydrogen-centered octahedra [H(D)Cs-6](5+) and isolated Cs+. The structure crystallizes in the hexagonal space group P6(3)/mcm (193) with the cell parameters a = 11.1108(3) angstrom, c = 18.2149(5) angstrom, Z = 2.
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| 2. |
- Fahlquist, Henrik, 1983-, et al.
(författare)
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SrH2Mg2[Co(I)H5], BaH2Mg5[Co(-I)H4]2 and RbH2Mg5[Co(-I)H4 Ni(0)H4] illustrate how small variations in counter ions are important for the solid state stabilization of 3d-transition metal hydrido complexes as well as influencing electrical and magnetic properties
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Variations in the counter ion support to low valent 3d transition metal hydrido complexes in solids state hydrides influence formal oxidation states as well as their electrical properties. In a combined study using neutron scattering and first principle calculations a very low formal oxidation state of (-I) can be described for cobalt in a slightly distorted tetrahedral Co(-I)H4-complex in BaH2Mg5[Co(-I)H4]2 and in the structurally closely related RbH2Mg5[Co(-I)H4 Ni(0)H4]. This indicates that the electron “back donating” effect via the polarisable hydride ions to the counter ions in the solid state hydrides, can be compared to more conventional “back bonding” and reduce the oxidation state down to -I. The hydrides were synthesised by hot sintering of transition metal powders with the corresponding binary alkali- and alkaline earth hydrides. In the similarly synthesized SrH2Mg2[Co(I)H5] cobalt is formally +I-valent, showing a high sensitivity to subtle differences in the counter ion framework.
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| 3. |
- Fahlquist, Henrik, 1983-
(författare)
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Transition Metal Hydride Complexes and Hydrogenated Gallium Clusters : Synthesis and Structural Properties
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Synthesis and structural characterisation of metal hydrides in two important systems are presented. The first system presented is low valent cobalt and nickel complex hydrides with the compositions BaMg5Co2H10, RbMg5CoNiH10, SrMg2CoH7and Sr4Mg4Co3H19 featuring nickel with oxidation state of 0 and cobalt with oxidation state +I and -I. The second system presented is polyanionic gallium complex hydrides with the compositions RbGaH2, RbxK(1−x)GaH2 (0.5≤x≤1), CsxRb(8−x)Ga5H15 (0≤x≤8) and Cs10Ga9H25 featuring novel hydrogenous polyanionic gallium hydride clusters mimicking common hydrocarbons. The syntheses of the compounds were performed at elevated temperatures and at moderate hydrogen pressures (50-100 bar). The structural investigations were mainly done by X-ray powder diffraction (XRPD) and neutron powder diffraction (NPD). The metal-hydrogen bond was investigated by vibrational spectroscopy using Fourier Transform IR-spectroscopy (FTIR) and Inelastic Neutron Scattering (INS).By subtle changes in the compositions of the hydrides it was possible to induce major changes in band gaps, oxidation states and structures.
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