Aluminabenzene–Zirconium Complexes: Intramolecular Coordination of Chloride to Aluminum

The
reaction of the previously reported anionic aluminabenzene
with zirconium chlorides (CpZrCl3, Cp*ZrCl3,
and ZrCl4) gave novel zirconium complexes bearing aluminabenzene
ligand(s). The X-ray crystallographic analysis of the resulting complexes
revealed that the aluminabenzene ligand(s) coordinated to the zirconium
center in an η5-fashion as a six-electron donor.
Chloride ligand(s) on the zirconium center intramolecularly coordinated
to the Lewis acidic aluminum atom in the aluminabenzene ring. The
variable-temperature 1H NMR experiment showed a dynamic
process for dissociation and recoordination of chloride to the aluminum
center.