[Bi₁₂Ni₇(CO)₄]^4–: Aggregation of Intermetalloid Clusters by Their Thermal Deligation and Oxidation

Reported are the synthesis and structure of the anionic intermetalloid cluster [Bi₁₂Ni₇(CO)₄]^4–. It was synthesized from the known smaller clusters Bi₃Ni₄(CO)₆^3–, Bi₃Ni₆(CO)₉^3–, and Ni@Bi₆Ni₆(CO)₈^4– by their aggregation as a result of thermal deligation and oxidation. The new cluster is structurally characterized by single-crystal X-ray diffraction in the compound (K­[crypt])₄[Bi₁₂Ni₇(CO)₄] (<b>1</b>), and its presence in solution is confirmed by electrospray mass spectrometry. It can be viewed as composed of a Ni-centered icosahedral core of Bi₆Ni₆(CO)₄ where two diametrically opposed Ni atoms are capped by Bi₃ triangles. However, its electron count is rationalized based on a structure made of fused tetrahedra

A Stannyl-Decorated Zintl Ion [Ge₁₈Pd₃(Sn^<i>i</i>Pr₃)₆]^2–: Twinned Icosahedron with a Common Pd₃‑Face or 18-Vertex <i>Hypho</i>-Deltahedron with a Pd₃‑Triangle Inside

We report the synthesis and characterization of the title anion which has a germanium/palladium cluster core of [Ge₁₈Pd₃] and six tri-isopropyl tin substituents. Its two Ge₉-halves are the first examples of germanium deltahedra with three nonsilyl substituents, tri-isopropyl tin in this case. The new cluster is made by a reaction of an acetonitrile suspension of K₄Ge₉ with ^<i>i</i>Pr₃SnCl that generates primarily tristannylated 9-atom clusters [Ge₉{Sn^<i>i</i>Pr₃}₃]⁻, followed by addition of Pd­(PPh₃)₄ to the reaction mixture. It was structurally characterized by single-crystal X-ray diffraction in [K­(222crypt)]₂[Ge₁₈Pd₃{Sn^<i>i</i>Pr₃}₆]·^<i>i</i>Pr₂O and was also confirmed in solution by ESI-MS and NMR. The new anion can be viewed both as a dimer of face-fused icosahedra (twinned icosahedron) with a common Pd₃-face, i.e., [(^<i>i</i>Pr₃Sn)₃Ge₉Pd₃Ge₉(Sn^<i>i</i>Pr₃)₃]^2– that resembles but is not isoelectronic with the known borane version B₂₁H₁₈^– or as a large <i>hypho</i>-deltahedron of 18 Ge-atoms with a triangle of Pd₃ inside, i.e., [Pd₃@Ge₁₈(Sn^<i>i</i>Pr₃)₆]^2–. DFT calculations show a very large HOMO–LUMO gap of 2.42 eV

Bi₇^3–: The Missing Family Member, Finally Isolated and Characterized

The synthesis and structure of Bi₇^3–, the only missing member of the family of heptanuclear pnictogen cluster anions Pn₇^3– (Pn = pnictogen, a group 15 element excluding the unique nitrogen), is reported. The new species is synthesized by oxidation of a solution of K₅Bi₄ by the solvent pyridine in the presence of (C₆H₆)­Cr­(CO)₃. The existence of the species in solution is confirmed by electrospray mass spectrometry, while its structure is elucidated by single-crystal X-ray diffraction in the compound [K­(2,2,2-crypt)]₃Bi₇·2py (monoclinic, <i>P</i>2₁/<i>n</i>, <i>a</i> = 13.8739(13) Å, <i>b</i> = 24.878(2) Å, <i>c</i> = 26.401(2) Å, β = 96.353(4)°, <i>V</i> = 9056.5(14) ų, <i>Z</i> = 4, and R1/wR2 = 0.0636/0.1390 for the observed data and 0.0901/0.1541 for all data)

Eclipsed- and Staggered-[Ge₁₈Pd₃{E^<i>i</i>Pr₃}₆]^2– (E = Si, Sn): Positional Isomerism in Deltahedral Zintl Clusters

We report the synthesis and characterization of the cluster anions [Ge₁₈Pd₃{Si^<i>i</i>Pr₃}₆]^2– (<b>1</b>) with a core of face-fused twinned icosahedra, Ge₁₈Pd₃, and two sets of three ^<i>i</i>Pr₃Si-substituents positioned in “eclipsed” geometry. The new anion is a positional isomer of the recently reported “staggered” stannyl-ligated counterpart [Ge₁₈Pd₃{Sn^<i>i</i>Pr₃}₆]^2– (<b>2</b>), showing the possibility to find such positional isomerism in Zintl clusters. Both anions are characterized by single-crystal X-ray diffraction, ¹H and ¹³C NMR, and negative-ion ESI-MS. Using relativistic DFT calculations, we elucidate and discuss the reasons for the different positioning of the ligands in the stannyl- and silyl-functionalized species

Eclipsed- and Staggered-[Ge₁₈Pd₃{E^<i>i</i>Pr₃}₆]^2– (E = Si, Sn): Positional Isomerism in Deltahedral Zintl Clusters

We report the synthesis and characterization of the cluster anions [Ge₁₈Pd₃{Si^<i>i</i>Pr₃}₆]^2– (<b>1</b>) with a core of face-fused twinned icosahedra, Ge₁₈Pd₃, and two sets of three ^<i>i</i>Pr₃Si-substituents positioned in “eclipsed” geometry. The new anion is a positional isomer of the recently reported “staggered” stannyl-ligated counterpart [Ge₁₈Pd₃{Sn^<i>i</i>Pr₃}₆]^2– (<b>2</b>), showing the possibility to find such positional isomerism in Zintl clusters. Both anions are characterized by single-crystal X-ray diffraction, ¹H and ¹³C NMR, and negative-ion ESI-MS. Using relativistic DFT calculations, we elucidate and discuss the reasons for the different positioning of the ligands in the stannyl- and silyl-functionalized species