Synthesis and crystal structure of a new alkaline earth nickel phosphide phase: BaNi9P5

Metal-Rich Phosphides Obtained from the Lead Flux: Synthesis, Crystal, and Electronic Structure of Sr5Pt12P9 and BaPt3P2

Using a high-temperature ampoule technique and lead metal as a flux, we have grown single crystals and determined crystal structures from single-crystal X-ray diffraction data of two metal-rich phosphides, Sr₅Pt₁₂P₉ (P 2₁/m, a = 6.1472(3) Å, b = 25.1713(13) Å, c = 6.4635(3) Å, β = 99.604(2)°, Z = 2, R₁ = 0.0326, wR₂ = 0.0786) and BaPt₃P₂ (P 2₁2₁2₁, a = 6.3605(6) Å, b = 6.8541(7) Å, c = 11.3493(12) Å, Z = 4, R₁ = 0.0231, wR₂ = 0.0501). Both compounds belong to their own structure types and feature 3D networks of Pt and P atoms, with the channels occupied by alkaline earth metal cations. Density functional theory calculations reveal Sr₅Pt₁₂P₉ to be a metal, while BaPt₃P₂ is a narrow-gap semiconductor with a band gap of 0.24 eV. Bonding analysis shows that both compounds feature networks of prominent covalent localized Pt-P bonds, responsible for their structural stability, as well as additional weaker and, likely, less localized Pt-Pt interactions.

The Metal Flux: A Preparative Tool for the Exploration of Intermetallic Compounds

This review highlights the use and great potential of liquid metals as exotic and powerful solvents (i.e. fluxes) for the synthesis of intermetallic phases. The results presented demonstrate that considerable advances in the discovery of novel and complex phases are achievable utilizing molten metals as solvents. A wide cross-section of examples of flux-grown intermetallic phases and related solids are discussed and a brief history of the origins of flux chemistry is given. The most commonly used metal fluxes are surveyed and where possible, the underlying principal reasons that make the flux reaction work are discussed.

Ni x P12-Käfige – Die Kristallstrukturen der Verbindungen SrNi9P5 (x = 18) und BaNi10P6 (x = 14)

The new ternary phosphides SrNi9P5 and BaNi10P6 were synthesized by heating the elements at 900°–1100°C. Single crystal X-ray methods revealed that SrNi9P5 is isotypic with BaNi9P5 and crystallizes hexagonally [P63/mmc; Z = 2; a = 6.529(1) Å, c = 10.732(1) Å], whereas BaNi10P6 forms a new structure with orthorhombic symmetry [Cmca, Z = 4; a = 6.449(1) Å, b = 16.191(1) Å, c = 8.784(1) Å]. The structures are best described as an arrangement of alkaline-earth metal atoms, which are surrounded by Ni18P12(SrNi9P5) and Ni14P12 cages (BaNi10P6), respectively.