Identifying a structural preference in reduced rare-earth metal halides by combining experimental and computational techniques

Simon Steinberg; Jakoah Brgoch; Gordon J Miller; Gerd Meyer

doi:10.1021/ic300838a

Identifying a structural preference in reduced rare-earth metal halides by combining experimental and computational techniques

Inorg Chem. 2012 Nov 5;51(21):11356-64. doi: 10.1021/ic300838a. Epub 2012 Oct 5.

Authors

Simon Steinberg¹, Jakoah Brgoch, Gordon J Miller, Gerd Meyer

Affiliation

¹ Department of Inorganic Chemistry, University of Cologne, Greinstraße 6, 50939 Cologne, Germany.

PMID: 23039183
DOI: 10.1021/ic300838a

Abstract

The structures of two new cubic {TnLa(3)}Br(3) (Tn = Ru, Ir; I4(1)32, Z = 8; Tn = Ru: a = 12.1247(16) Å, V = 1782.4(4) Å(3); Tn = Ir: a = 12.1738(19) Å, V = 1804.2(5) Å(3)) compounds belonging to a family of reduced rare-earth metal halides were determined by single-crystal X-ray diffraction. Interestingly, the isoelectronic compound {RuLa(3)}I(3) crystallizes in the monoclinic modification of the {TnR(3)}X(3) family, while {IrLa(3)}I(3) was found to be isomorphous with cubic {PtPr(3)}I(3). Using electronic structure calculations, a pseudogap was identified at the Fermi level of {IrLa(3)}Br(3) in the new cubic structure. Additionally, the structure attempts to optimize (chemical) bonding as determined through the crystal orbital Hamilton populations (COHP) curves. The Fermi level of the isostructural {RuLa(3)}Br(3) falls below the pseudogap, yet the cubic structure is still formed. In this context, a close inspection of the distinct bond frequencies reveals the subtleness of the structure determining factors.