Unpredicted but It Exists: Trigonal Sc₂Ru with a Significant Metal–Metal Charge Transfer

Abstract

The Sc 2 Ru compound, obtained by high-temperature synthesis, was found to crystallize in a new trigonal hP 45 structure type [space group P 3̅ m 1; a = 9.3583(9) Å and c = 11.285(1) Å]: Ru@Sc 8 cubes, Ru@Sc 12 icosahedra, and uncommon Ru@Sc 10 sphenocoronae are the building blocks of a unique motif tiling the whole crystal space. According to density functional theory studies, Sc 2 Ru is a metallic compound characterized by multicenter interactions: a significant charge transfer occurs from Sc to Ru, indicating an unexpectedly strong ionic character of the interactions between the two transition metals. Energy calculations support our experimental results in terms of stability of this compound, contributing to the recurrent discussion on the limits of the high-throughput first-principles calculations for metallic materials design.

Flux Growth, Crystal Structure, and Chemical Bonding of Yb2PdGe3, an AlB2Superstructure within the Rare-Earth Series

“…Interestingly, these characteristic features of covalently bonded p -block elements are practically identical for both germanium and palladium. Such intriguing anionic behavior of palladium and other transition metals (e.g., Ru, Ir, Pt, Au, Ag) has been increasingly reported in the literature ,,− and considered responsible for unprecedented chemical properties. , Hence, the QTAIM effective charges indicate that the crystal structure of Yb 2 PdGe 3 is composed of false[ PdGe 3 false] ∞ 2 honeycomb anionic layers spaced by Yb cations.…”

Magnetic phase separation in the EuPdSn2ground state

“…Interestingly, Eu is the only QTAIM cation (+1.02) and Pd bears a negative effective charge of À0.92, enriching the family of intermetallic compounds containing an anionic late transition metal. [44][45][46][47][48][49][50] The Q eff (Eu) is almost half of the formal one supporting its involvement in covalent interactions. The shapes of the atomic basins are quite characteristic for transition metal rare-earth tetrelides: Eu cations are quite spherical whereas both Pd and Sn display polyhedral shapes, sharing convex surfaces with Eu and flat among them.…”