text: Treatment of tantalum pentachloride with hexamethylbenzene (CMe), aluminium, and aluminium trichloride gives [M(η-CMe)AlCl].
  Tantalum-alkyne complexes catalyze cyclotrimerizations. Some tantalum-alkyne complexes are precursors to allylic alcohols. Tantalacyclopropenes are invoked as intermediates.