Hafnium(IV) Chloride - Uses

Uses

Hafnium chloride is the precursor to highly active catalysts for the polymerization of alkenes, especially propylene. Typical catalysts are derived from tetrabenzylhafnium.

HfCl₄ is an effective Lewis acid for various applications in organic synthesis. For example, ferrocene is alkylated with allyldimethylchlorosilane more efficiently using hafnium chloride relative to aluminium trichloride. The greater size of Hf may diminish HfCl₄'s tendency to complex to ferrocene.

HfCl₄ increases the rate and control of 1,3-dipolar cycloadditions. It was found to yield better results than other Lewis acids when used with aryl and aliphatic aldoximes, allowing specific exo-isomer formation.

Hafnium chloride is also the precursor to highly active catalysts for the polymerization of alkenes, especially propylene. Typical catalysts are derived from tetrabenzylhafnium. It was recently reported that MgCl2 supported HfCl₄ in combination with AlEt3 or Dimethyltitanocene specifically produces polypropylene.