Synthesis and structures of Sc₇Cl₁₂ and Zr₆Cl₁₅

Abstract

Abstract The indicated nine‐electron clusters of scandium and zirconium are formed in transport reactions at 880/900°C and 750/600°C, respectively. Sc 7 Cl 12 (R¯3, a – 12.959(2), c – 8.825(2), Z – 3) can be described as c.c.p. Sc 6 Cl 12 clusters with isolated metal atoms in all octahedral interstices or as Sc 3+ (Sc 6 Cl 6 i Cl 6 i−a ) 3− with Sc 3+ in Cl i octahedra between Sc 6 Cl sheets. Metal‐metal distances within the cluster are 3.201−3.230(2) Å. Zr 6 Cl 12 i Cl crystallizes in the Ta 6 Cl 15 structure (Ia3d, a – 21.141(3) Å, Z – 16) with d(ZrZr) = 3,199–3.214(4) Å. Apparent residual electron density is found in the center of both clusters, amounting to Z∼7.6 (Sc) and ∼6 (Zr) based of refinement of oxygen in these positions. The effect is thought to probably arise from errors in the diffraction data rather than partial incorporation of light nonmetal atoms such as oxygen or fluorine. Observed metal‐metal distances are compared with those in other clusters.