AuPb 2 I 7 : A Narrow Bandgap Au 3+ Iodide Semiconductor.

Autor: Alexander GCB; Department of Chemistry, Northwestern University , Evanston, Illinois 60208, United States., Fabini DH, Seshadri R, Kanatzidis MG; Department of Chemistry, Northwestern University , Evanston, Illinois 60208, United States.
Jazyk: angličtina
Zdroj: Inorganic chemistry [Inorg Chem] 2018 Jan 16; Vol. 57 (2), pp. 804-810. Date of Electronic Publication: 2018 Jan 02.
DOI: 10.1021/acs.inorgchem.7b02723
Abstrakt: The unusual Au 3+ ternary halide AuPb 2 I 7 has been isolated from reactions of AuI, PbI 2 , and I 2 . AuPb 2 I 7 crystallizes in the triclinic P1̅ space group as micron-scale needles with cell dimensions a = 4.5170(3) Å, b = 7.3847(4) Å, c = 12.2970(7) Å, α = 76.374(4)°, β = 83.711(4)°, γ = 72.987(3)° at room temperature with ρ = 6.538 g/cm 3 and has no structural phase transition down to 100 K. The title compound has a unique three-dimensional structure composed of [Pb 2 I 7 ] 3- pseudolayers extending in [010] bridged by square planar Au 3+ at an oblique angle in the [001] direction. The pseudolayers are composed of 1 / [Pb 2 I 2 ] 2+ chains propagating down [100] linked by square planar I - ions through [010]. AuPb 2 I 7 has a bandgap of 1.17 eV and is stable in air for several days, before degrading to PbI 2 , Au 0 , and I 2 . Density functional theory calculations show that AuPb 2 I 7 is an indirect bandgap semiconductor where the bandgap stems predominantly from Au-I metal-ligand charge transfer.
Databáze: MEDLINE