Add a Pinch of Tetrel: The Transformation of a Centrosymmetric Metal into a Nonsymmorphic and Chiral Semiconductor

Shannon J Lee; Gayatri Viswanathan; Scott L Carnahan; Colin P Harmer; Georgiy Akopov; Aaron J Rossini; Gordon J Miller; Kirill Kovnir

doi:10.1002/chem.202104319

Add a Pinch of Tetrel: The Transformation of a Centrosymmetric Metal into a Nonsymmorphic and Chiral Semiconductor

Chemistry. 2022 Feb 16;28(9):e202104319. doi: 10.1002/chem.202104319. Epub 2022 Jan 12.

Authors

Shannon J Lee^{1

2}, Gayatri Viswanathan^{1

2}, Scott L Carnahan^{1

2}, Colin P Harmer^{1

2}, Georgiy Akopov^{1

2}, Aaron J Rossini^{1

2}, Gordon J Miller¹, Kirill Kovnir^{1

2}

Affiliations

¹ Department of Chemistry, Iowa State University, 50011, Ames, IA, USA.
² Ames Laboratory, US DOE, 50011, Ames, IA, USA.

Abstract

Centrosymmetric skutterudite RhP₃ was converted to a nonsymmorphic and chiral compound RhSi_0.3 P_2.7 (space group P2₁ 2₁ 2₁ ) by means of partial replacement of Si for P. The structure, determined by a combination of X-ray crystallography and solid state ³¹ P NMR, exhibits branched polyanionic P/Si chains that are unique among metal phosphides. A driving force to stabilize the locally noncentrosymmetric cis-RhSi₂ P₄ and fac-RhSi₃ P₃ fragments is π-electron back-donation between the Rh t_2g -type orbitals and the unoccupied antibonding Si/P orbitals, which is more effective for Si than for P. In situ studies and total energy calculations revealed the metastable nature of RhSi_0.3 P_2.7 . Electronic structure calculations predicted centrosymmetric cubic RhP₃ to be metallic which was confirmed by transport properties measurements. In contrast, the electronic structure for chiral orthorhombic RhSi_0.3 P_2.7 contained a bandgap, and this compound was shown to be a narrow gap semiconductor.

Keywords: chirality; crystal engineering; phase transitions; polymorphism; solid-phase synthesis.

Abstract

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