New Double Salts with Boron‐Centered Zirconium Clusters: Syntheses and Structures of Cs[ZrCl₅]·Cs₂[(Zr₆B)X₁₅] (X = Cl or Cl+I), and Anion Distribution in the Mixed Halide Phase

AbstractTwo new members of a double salt containing halide supported zirconium octahedra were obtained from solid state reactions. Single‐crystal X‐ray data refinements established the isotypic compounds as Cs[ZrCl5]·Cs2[(Zr6B)Cl15] (I) (R3¯c, Z = 6, a = 12.765(2), c = 34.652(6)Å, R1(F) = 0.0339, wR2(F2) = 0.0770) and the mixed halide Cs[ZrCl5]·Cs2[(Zr6B)Cl14.57(2)I0.43] (II) (R3¯c, Z = 6, a = 12.777(2), c = 34.668(7)Å, R1(F) = 0.0459, wR2(F2) = 0.1279), respectively. The structure contains a network of boron centered [(Zr6B)Cli12] clusters interbridged three‐dimensionally by 6/2 Xa‐a atoms at all zirconium vertices (X = Cl, or Cl+I, respectively). Within voids of the cluster network [ZrCl5]— anions and Cs+ cations are located, allowing for the description as a double salt. The [ZrCl5]— anion (D3h‐symmetry) has been found so far only in this structure type. The space requirement of a variety of transition metal complexes is estimated and compared with the volume of the [ZrCl5]— anion in order to see if other double salts are geometrically possible. Besides the unusual [ZrCl5]— ion the mixed chloride‐iodide structure reveals another interesting feature. Contrary to many other structures an ordered chlorine atom substitution by iodine is observed on the cluster interconnecting site. The phase width for Cs[ZrCl5]·Cs2[(Zr6B)Cl15‐xIx] has been found to cover 0 ≤ x ≤ 1.