Synthesis and molecular structure of [(Ph3P)2N]2[Os8(CO)22]

Synthesis of Well‐Defined Bicapped Octahedral Iron Clusters [(trenL)2Fe8(PMe2Ph)2]n (n=0, −1)

“…From our previous research on the synthesis of polynuclear complexes we have learned that well-defined octahedral hexanuclear clusters can be prepared by dimerization of two trinuclear units supported by hexamine ligands. [9,11] In the present report we expanded the ligand backbone into atetraamine moiety by use of tren to accommodate af ourth metal per ligand, affording bicapped octahedral octanuclear clusters.Prediction of polynuclear cluster geometry can be made by use of Wades rules, [23] later expanded by Lewis et al [24] to polycarbonyl clusters.P redictions by Wades rules are applicable to many cluster types and nuclearities. [25] Ther eported species 1 and 2a, b do not strictly follow these rules as the calculated number of skeletal electron pairs (Sk) is 6o r8 (although 7isthe expected number).…”

“…[9] In the present report we expanded the ligand backbone into a tetraamine moiety by use of tren to accommodate a fourth metal per ligand, affording bicapped-octahedral octanuclear clusters. Prediction of polynuclear cluster geometry can be made by use of Wade’s rules, [23] later expanded by Lewis et al [24] to polycarbonyl clusters. Wade’s rules predictions are applicable to many cluster types and nuclearities.…”

“…[26] This discrepancy may be in part to the geometry restriction imposed by the tren L 8− ligand in contrast to the self-assembled polycarbonyl clusters, which relax to the respective thermodynamically stable configuration. In fact, there are no reported [27] bicapped-octahedral molecular clusters for first-row transition metal (TM) homonuclear clusters; though examples with second-row TM [7b, 28] and third-row TM, [24b, 29] as well as one heterobimetallic [Os 6 Pt 2 ] cluster are known. [30] Thus, the ligand framework reported here allowed us to synthesize octairon clusters with a rare cluster configuration and redox tunability.…”

Large gallanes and the PSEPT theory: a theoretical study of Ga n H n+2 clusters (n = 7–9)

“…Octagallane (10) In accordance with the modified W-M rule [8], the octagallane Ga 8 H 10 should adopt a closed structure with the same arrangement as B 8 H 8 2− [48,49]-called a dodecahedron or bisdisphenoid (eight vertices, twelve edges, and twelve triangular facets)-with eight terminal hydrogen atoms and two others, ensuring two Ga-Ga bridged bonds. It can also described as two interpenetrating tetrahedra, or it can be derived from a square antiprism in which the square bases become folded lozenges (Scheme 3).…”

[Tl8]6− in Cs8Tl8O: A Naked Eight‐Vertex closo‐Deltaeder as a Cluster Anion

“…The earlier examples of bicapped octahedra were limited to transition metals. [21] The lack of such clusters within the boron or carbon chemistry was ascribed to the high strain of only four orbitals (per atom) contributing to the bonding. [22] When moving to the higher homologues, d orbitals are available which might reduce the angular strain.…”