Crystal structures of the metal diborides ReB2, RuB2, and OsB2 from neutron powder diffraction - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Journal of Inorganic and General Chemistry / Zeitschrift für anorganische und allgemeine Chemie Année : 2010

Crystal structures of the metal diborides ReB2, RuB2, and OsB2 from neutron powder diffraction

Résumé

Owing to the very small scattering power of the light element, the crystal structures of metal borides that contain heavy metal atoms are difficult to determine unambiguously from X-ray diffraction data only. Using neutron diffraction methods and applying them to isotopically enriched 11B boride powders, the crystal structures of ReB2, RuB2, and OsB2 were re-determined and analysed with respect to the boron atom arrangement. In accordance with the findings from X-ray diffraction experiments, the structures exhibit corrugated boron atom layers of conjugated six-rings, either seat-like (ReB2) or boat-like (RuB2, OsB2). ReB2 crystallizes in the hexagonal crystal system, space group P63/mmc (no. 194, a = 290.05(1) pm, c = 747.72(1) pm); OsB2 and RuB2 are isostructural and crystallize orthorhombically, space group Pmmn (no. 59, a = 464.479(5) pm, b = 286.515(3) pm, c = 404.560(6) pm (RuB2); a = 468.408(5) pm, b = 287.255(3) pm, c = 407.693(6) pm (OsB2)). Boron-boron distances vary between 181.7 and 189.9 pm. For RuB2 and OsB2, shortest metal-boron distances range from 217.2 to 217.3 pm, indicating a covalent interaction between metal and boron, compared to 222.7 pm for ReB2. Metal-metal distances are between 286.5 pm and 302.2 pm. All three compounds have been described as very hard or incompressible materials.

Mots clés

Fichier principal
Vignette du fichier
PEER_stage2_10.1002%2Fzaac.201000101.pdf (1.77 Mo) Télécharger le fichier
Origine : Fichiers produits par l'(les) auteur(s)

Dates et versions

hal-00599863 , version 1 (11-06-2011)

Identifiants

Citer

Barbara Albert. Crystal structures of the metal diborides ReB2, RuB2, and OsB2 from neutron powder diffraction. Journal of Inorganic and General Chemistry / Zeitschrift für anorganische und allgemeine Chemie, 2010, 636 (9-10), pp.1783. ⟨10.1002/zaac.201000101⟩. ⟨hal-00599863⟩

Collections

PEER
46 Consultations
362 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More