Campus Units

Chemistry, Ames Laboratory

Document Type

Article

Publication Version

Published Version

Publication Date

2013

Journal or Book Title

Inorganic Chemistry

Volume

52

First Page

13623

Last Page

13630

DOI

10.1021/ic402145k

Abstract

Quantitative syntheses, structure determinations and interpretations, and band calculations are reported for the nonstoichiometric rhombohedral (Rc) and monoclinic (C2/c) Sr2Au6(Au3–xTx) (T = Zn, Ga) compounds. Several different compositions of the two Sr phases were similarly refined from single crystal X-ray diffraction data as Rc: a ≈ 8.43 Å, c ≈ 21.85 Å, Z = 6 and C2/c: a ≈ 14.70 Å, b ≈ 8.47 Å, c ≈ 8.70 Å, β ≈ 123.2°, Z = 4. The Rc Zn phase is stable in the composition region x ∼ 2.5–2.9 whereas its C2/c neighbor is the major product at x ∼ 2.2–2.3. Gallium versions of both were also identified. Both Rc and C2/c structural types contain hexagonal-diamond-like gold superlattices stuffed with strings of interstitial Sr and disordered triangular (Au,T)3 units. The latter space group is a maximal, nonisomorphic subgroup of the former, and the decrease in interstitial radius from Ba to Sr (∼0.08 Å experimentally) evidently drives the symmetry reduction, relaxation, and small distortions, principally around the Sr sites. Au–Au bonding among the Au hexagons in the host lattices and with gold components in the triangular interstitials is dominant and reflected in their tight packing and short interatomic separations.

Comments

This is an article from Inorganic Chemistry 52 (2013): 13623, doi: 10.1021/ic402145k. Posted with permission.

Copyright Owner

American Chemical Society

Language

en

File Format

application/pdf

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