Octametallic Cluster of Cp*Ir(glycinato) Cations

Removal of chloride from Cp*Ir­(glycinato)Cl in noncoordinating
solvents with Ag­[PF6] or Tl­[PF6] leads to the
formation of a closed octametallic loop of cations. The same loop
also sequesters a number of PF6– counter
anions. This is in contrast with reports that piano-stool complexes
with amino acids form only trimetallic [Cp*Ir­(aminoacidato)]33+ moieties upon creating the cation. Cp*Ir­(glycinato)­Cl
also forms a trimetallic compound as well as a octametallic compound,
and the octametallic vs trimetallic formation appears to be dependent
on the anion. The synthesis and characterization of the octametallic
complex, as well as some monometallic and trimetallic compounds, are
reported, including the X-ray crystal structures.