title: Room-temperature synthesis of nickel borides via decomposition of NaBH(4) promoted by nickel bromide.
abstract: We report the formation of nickel borides, at room temperature and pressure, from the decomposition of NaBH(4) promoted by the addition of nickel bromide at different concentrations in a dispersing organic medium, tetrahydrofuran and pentane. The nickel borides, formed as amorphous powders, were analyzed, and the structure information served as input for modeling a periodic lattice structure with the same composition. Experimentally, the nickel boride phases were predominantly composed of a boron-rich phase with composition NiB(3). Combining FT-IR, X-ray diffraction analyses, and theoretical structure determination, we suggest for it a monoclinic structure, with symmetry group P2(1)/c, lattice parameters a =3.038 Å, b = 8.220 Å, c = 5.212 Å, α = β = 90.00° and γ = 87.57°. The enthalpies of formation of the nickel boride phases, as well as the lattice stability, were calculated using density functional theory and density functional perturbation theory methods.
authors.affiliation: ETH Zürich, Department of Chemistry and Applied Biosciences, Lab Inorganic Chemistry, Wolfgang-Pauli Strasse 10, CH-8093 Zürich, Switzerland. riccarda.caputo@inorg.chem.ethz.ch
authors.forename: Riccarda
authors.initials: R
authors.lastname: Caputo
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Guzzetta
authors.forename: Alexander
authors.initials: A
authors.lastname: Angerhofer
mesh_terms: D001880:Boranes / Q000138:chemical synthesis* / Q000737:chemistry; D001894:Borohydrides / Q000737:chemistry*; D001965:Bromides / Q000737:chemistry*; D018360:Crystallography, X-Ray; D008958:Models, Molecular; D009532:Nickel / Q000737:chemistry*; D013696:Temperature
chemical_list: D001880:Boranes; D001894:Borohydrides; D001965:Bromides; C049893:nickel boride; D009532:Nickel; C025364:sodium borohydride