Similar K@Au10Sn10 polyhedra in the markedly different structures of KAu4Sn6 and KAu3Sn3. Syntheses and characterization

TitleSimilar K@Au10Sn10 polyhedra in the markedly different structures of KAu4Sn6 and KAu3Sn3. Syntheses and characterization
Publication TypeJournal Article
Year of Publication2008
AuthorsLi B, Corbett JD
Journal TitleInorganic Chemistry
Volume47
Pages3610-3616
Date PublishedMay
Type of ArticleArticle
ISBN Number0020-1669
Accession NumberISI:000255380500026
Keywordsau, clusters, gold substitution, intermetallic compounds, networks, phases, rb, solid-state, STABILIZATION, tin
Abstract

These compounds were synthesized by high-temperature reactions of the elements in welded Ta tubes and characterized by X-ray diffraction methods and linear muffin-tin orbital (LMTO) calculations. AAu(4)Sn(6) (A = K, Rb) have a new structural type (Fddd, Z = 8), and KAu3Sn3 (Pmmn, Z = 2) is isostructural with SrAu3In3. Both orthorhombic structures contain similar condensed K@Au10Sn10 polyhedral building blocks, which can be described as overall 6-8-6 arrangements of planar rings or, alternatively, as hexagonal prisms centered by K and augmented about the waists by 8-rings of Au and Sn. However, the 3D Au-Sn networks differ appreciably in both composition and the modes of condensation. In KAu3Sn3, the prisms stack by sharing both hexagonal faces with like neighbors along a, whereas those in KAu4Sn6 condense in a complex zigzag network. Compared with related indium systems,, the structure change from KAu4In6 (P6m2, Z = 1) to KAu4Sn6 apparently illustrates the effect of complex factors such as atom size and valence electron counts on structure, whereas the SrAu3In3 and KAu3Sn3 pair are isotypic. Both compounds are Pauli-paramagnetic and inert to water at room temperature for several days. Tight-binding electronic structure (LMTO) calculations emphasize the dominance and strength of the heteroatomic Au-Sn bonding.

DOI10.1021/ic701997x
Alternate JournalInorg. Chem.