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

Abstract

Centrosymmetric skutterudite RhP 3 was converted to a nonsymmorphic and chiral compound RhSi 0.3 P 2.7 (space group P2 1 2 1 2 1 ) 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-RhSi 2 P 4 and fac-RhSi 3 P 3 fragments is πelectron 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 RhP 3 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.

Probing of the Noninnocent Role of P in Transition-Metal Phosphide Hydrogen Evolution Reaction Electrocatalysts via Replacement with Electropositive Si

“…The success of the arc-melted Ni–Si precursor relies on the idea that both refractive elements are introduced into the reaction medium with P at the same time and are both in close spatial proximity. This methodology works well for the synthesis of many complex ternary and multinary materials. − Interestingly, using the arc-melted precursor methodology, a new Ni 3 SiP 2 phase was synthesized along with the reported Ni 2 SiP, Ni 5 Si 2 P 3 , and Ni 7 Si 2 P 5 phases. Reference materials were synthesized by arc-melting for NiSi, and by the direct reaction of Ni and P in a stoichiometric ratio in identical conditions to those of NiSi 1– x P x for Ni 5 P 4 (Figure S2).…”

Machine Learning-Guided Discovery of Ternary Compounds Containing La, P, and Group 14 Elements

“…It should be noted that partial occupancies and atomic mixings between Si and P are not considered in our predictions because it is challenging for DFT to deal with such situations. Nevertheless, majority of studied M–Si–P phases show no such mixing. − Initial assignment of Si/P is done based on single-crystal X-ray diffraction. High quality datasets allow to refine P/Si.…”

“…High quality datasets allow to refine P/Si. We have utilized 31 P and 29 Si solid-state NMR spectroscopy to verify Si/P assignments. − We hypothesized that the ML-guided DFT predictions for ordered La–Si–P system are reliable.…”

Enhancing Properties with Distortion: A Comparative Study of Two Iron Phosphide Fe2P Polymorphs

“…48 Polymorphism can also significantly vary the transport properties of complex ternary and quaternary materials, such as clathrates or tetrel-phosphides. 6,40,49 The violet-P 11 polymorph of phosphorus shows a bandgap >2.0 eV, which is considerably larger than for other white or red P allotropes. 50 Many new polymorphs can be made using different flux media or low temperature profiles to access metastable phases.…”

“…CuSe 2 with a pyrite crystal structure shows superconductivity at a higher temperature than the CuSe 2 marcasite phase. , The semimetallic nature of the cubic NiP 2 polymorph requires less overpotential for hydrogen/oxygen evolution reactions (HER/OER) than for the semiconducting monoclinic NiP 2 phase . Polymorphism can also significantly vary the transport properties of complex ternary and quaternary materials, such as clathrates or tetrel-phosphides. ,, The violet-P 11 polymorph of phosphorus shows a bandgap >2.0 eV, which is considerably larger than for other white or red P allotropes . Many new polymorphs can be made using different flux media or low temperature profiles to access metastable phases .…”