Phosphine‐Stabilized Copper–Antimony Clusters: Syntheses, Structures, and Theoretical Investigations of [Cu₁₂(SbSiMe₃)₆(PiPr₃)₆], [Cu₄₀Sb₁₂(PMe₃)₂₀], and [Cu₄₅Sb₁₆(PEt₂Me)₁₆]

Molecular alloys: The composition and properties of the title compounds suggests that they can be regarded as molecular alloys. The single-crystal structures of these phosphine-stabilized compounds are determined (see picture for structure of [Cu45Sb16(PEt2Me)16]; Sb red, Cu blue, P green) and confirmed by density functional theory (DFT) calculations.