Kaminsky catalyst (syndiotactic)

Other names: dichlorido(η⁵-fluorenyl)(η⁵-cyclopentadienyl)hafnium

C₁₉H₁₄HfCl₂

16/50 common

Dichlorido(η⁵-fluorenyl)(η⁵-cyclopentadienyl)hafnium is a kind of Kaminsky catalyst for the production of syndiotactic polyolefins, which means that produced polymer sites have the alternating stereochemistries. Its structure features a hafnium center coordinated to a fluorenyl ligand, a cyclopentadienyl (Cp) ligand, and two chloride ligands, creating a constrained geometry that enforces syndiotacticity during polymerization. Typically activated by methylaluminoxane (MAO), it enables precision polymerization of highly stereospecific polyolefin materials.