Add a Pinch of Tetrel: The Transformation of a Centrosymmetric Metal into a Nonsymmorphic and Chiral Semiconductor. Issue 9 (12th January 2022)

• Record Type: Journal Article
• Authors: Lee, Shannon J.; Viswanathan, Gayatri; Carnahan, Scott L.; Harmer, Colin P.; Akopov, Georgiy; Rossini, Aaron J.; Miller, Gordon J.; Kovnir, Kirill
• Is Part Of: Chemistry. Volume 28:Issue 9(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-01-12
• Subjects: chirality -- crystal engineering -- phase transitions -- polymorphism -- solid-phase synthesis; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.202104319
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: Centrosymmetric skutterudite RhP3 was converted to a nonsymmorphic and chiral compound RhSi0.3 P2.7 (space group P 21 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 t2g ‐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 RhSi0.3 P2.7 . 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 RhSi0.3 P2.7 contained a bandgap, and this compound was shown to be a narrow gap semiconductor. Abstract : The substitution of a small amount of silicon to the known composition of RhP3 (centrosymmetric space group Im 3 ‾ ) yields novel RhSi0.3 P2.7 (space group P 21 21 21 ) which has a noncentrosymmetric, nonsymmorphic, and chiral crystal structure. We hypothesize that a combination of M − Tt and M − Pn bonding favors noncentrosymmetric structures. Therefore, by adding a "pinch" of tetrel to known centrosymmetric metal pnictide compositions, new noncentrosymmetric structures may be realized.