The synthesis and reactivity of the heptanuclear dianion [Os7(CO)20]2- including the synthesis and structural characterizations of the compounds [Os7(CO)20(AuPEt)32] and [Os8(CO)20(η6-C6H6]

Angelo J. Amoroso, Brian F G Johnson, Jack Lewis, Chi Keung Li, Catherine A. Morewood, Paul R. Raithby, Maria D. Vargas, Wing Tak Wong

Research output: Journal article publicationJournal articleAcademic researchpeer-review

15 Citations (Scopus)


Reduction of the heptaosmium cluster [Os7(CO)21] With [Et4N][NH4) gives the cluster dianion [Os7(CO)20]2-, 1, in high yield. The reaction of the dianion with [AuP R3Cl] (R=Et or Ph) in the presence of TlPF6 forms [Os7((CO)20(AuP R3)2] [R=Et (2a);R = Ph(2b)] in 80% yield, while the corresponding reaction with (Os(C6H6)(CH3CN)3]2+ gives [Os8(CO)20 (η6-C6H6)] (3) in reasonable yield (ca. 30%). The dianion, 1, and the clusters 2 and 3 have been fully characterized by bout spectroscopic and crystallographic methods. The crystal structure of the [Ph4P]+ salt of 1 shows that the metals in the anion adopt a capped octahedral geometry, with all twenty carbonyl ligands in terminal sites. The metal core geometry in 2a is best described as a tricapped octahedron, and is based on the structure of the dianion 1 with two adjacent octahedral faces capped by the Au atoms of the two AuPEt3 groups. In a similar fashion, the geometry of 3 is related to that of 1 with the addition of an Os(C6H6) unit capped to a triangular face, to give a bicapped octahedral framework.
Original languageEnglish
Pages (from-to)163-173
Number of pages11
JournalJournal of Cluster Science
Issue number1
Publication statusPublished - 1 Mar 1995
Externally publishedYes


  • arene
  • Cluster carbonyl
  • crystal structure
  • gold
  • osmium

ASJC Scopus subject areas

  • Inorganic Chemistry

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