The Prolific Ternary System Pt/Sn/Nd: Insertion of Pt into the Structures of Sn/Nd Intermetallics Yields Structural...

The understanding of structure and bonding in intermetallic phases still lags behind that of molecular compounds. For that reason, exploring intermetallic phases and identifying structural patterns and relationships are particularly important for closing this knowledge gap. In particular, here we report on the addition of increasing amounts of platinum to ∼2:1 mixtures of tin and neodymium, which yields eight ternary Pt/Sn/Nd compounds, four of which have not been reported before. Interestingly, except for PtSnNd (1), all observed ternary phases of the system can be derived from the binary compounds Sn₂Nd and Sn₅Nd₂ by adding Pt to the composition(s), as they lie on or close to two lines: Sn₂Nd-Pt (Pt_0.21(1)Sn₂Nd (2), PtSn₂Nd (3), Pt_1.33Sn₂Nd (4), Pt_2-Sn₂₊Nd (x = 0.27(3), 5), and Pt₃Sn₂Nd (6)) or Sn₅Nd₂-Pt (Pt_1.5Sn_5-Nd₂ (x = 0.16(2), 7) and Pt₃Sn₅Nd_2- (x = 0.161(8), 8)). While the introduction of increasing amounts of Pt to the binaries Sn₂Nd and Sn₅Nd₂ leads to stepwise changes in the coordination environment of Nd, Pt preserves its coordination over the entire system in the form of interpenetrating bipyramidal {PtSn₅Nd₅} clusters.