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Design of High‐Temperature Syntheses on the Example of the Heavy‐Atom Cluster Compound Sn[PtBi 6 I 12 ]
Author(s) -
Herz Maria A.,
Finzel Kati,
Ruck Michael
Publication year - 2022
Publication title -
zeitschrift für anorganische und allgemeine chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.354
H-Index - 66
eISSN - 1521-3749
pISSN - 0044-2313
DOI - 10.1002/zaac.202200080
Subject(s) - isostructural , crystallography , bismuth , octahedron , band gap , cluster (spacecraft) , phase diagram , chemistry , atom (system on chip) , semiconductor , crystal structure , isothermal process , materials science , phase (matter) , thermodynamics , physics , organic chemistry , optoelectronics , computer science , programming language , embedded system
Abstract Investigations into potential topological materials yielded the new subiodide Sn[PtBi 6 I 12 ]. The combination of thermal analyses with phase analyses of the products of isothermal ex situ syntheses allowed the establishment of a complex high‐temperature synthesis protocol for the crystal growth of the target phase despite the lack of knowledge of the quaternary phase diagram. A special challenge was to prevent the formation of competing compounds of the solid solution series (Bi 2x Sn 1–3x )[PtBi 6 I 12 ] with x ≠0. Sn[PtBi 6 I 12 ] crystallizes, isostructural to Pb[PtBi 6 I 12 ], in the rhombohedral space group R 3 ‾ with lattice parameters a =1583.2(2) pm and c =1089.70(10) pm. The compound consists of cuboctahedral [PtBi 6 I 12 ] 2− clusters and Sn 2+ cations in an octahedral coordination between the trigonal faces of two cluster units, thereby concatenating them into infinite linear chains. The chains are connected via Bi ⋯ I inter‐cluster bridges, creating a high‐entropy variant of the NaCl structure type. Sn[PtBi 6 I 12 ] is a semiconductor with an experimental bandgap of 0.8(1) eV. Fully relativistic density functional theory calculations including an implementation of the bifunctional formalism for the exchange energy indicate a topologically trivial bandgap of 0.81 eV between bands that are dominated by contributions of bismuth and iodine.