Structure and Reactivity of the β-Agostic [ansa-Cp-arene]Ta(nPr) Cation: Ambivalent Behavior Induced by Intramolecular Arene Coordination.

The article describes the cationic tantalum complexes bearing an arene-substituted cyclopentadienyl ligand involving ansa-(n5-C5H4>,n6-arene) coordination. According to the authors, the coordination of the pendant arene allows resonance stabilization of low-valent species, resulting in ambivalent character. They add the cationic ansa-Cp-arene tantalum complexes can display both migratory insertion and oxidative addition reactions.