Stepwise formation of metallo-prisms of iridium and rhodium complexes bearing pentamethylcyclopentadienyl ligands

Reactions of [M(Cp∗)Cl(μ-Cl)]2 (M = Ir(1a); M = Rh(1b)) with tridentate ligands tpt (tpt = 2,4,6-tripyridyl-1,3,5-triazine) gave the corresponding trinuclear complexes [M3(Cp∗)3(μ3-4-tpt-κN)Cl6] (M = Ir(2a); M = Rh(2b)), which can be converted into hexanuclear complexes [M6(Cp∗)6(μ3-4-tpt-κN)2(μ-Cl)6](O3SCF3)6 (M = Ir(3a); M = Rh(3b)) by treatment with AgO3SCF3, respectively. X-ray of 3b revealed that each of six pentamethylcyclopentadienyl metal moieties was connected by two μ-Cl-bridged atoms and a tridentate ligand to construct a cation triangular metallo-prism cavity with the volume of about 273 Å3 based on the distance of the two triazine moieties is 3.62 Å.