US Patent Issued to NOVA Chemicals (International) on Nov. 25 for "Synthesis of metallocene polymerization catalyst" (Canadian Inventors)

ALEXANDRIA, Va., Nov. 25 -- United States Patent no. 12,479,874, issued on Nov. 25, was assigned to NOVA Chemicals (International) S.A. (Fribourg, Switzerland).

"Synthesis of metallocene polymerization catalyst" was invented by Charles Carter (Calgary, Canada) and Janelle Smiley-Wiens (Calgary, Canada).

According to the abstract* released by the U.S. Patent & Trademark Office: "A one pot synthetic method for making a bridged cyclopentadienyl/fluorenyl type ligand the corresponding ansa metallocene polymerization catalyst. In a key step, a cyclopentadienide/fluorenide dianion is prepared by combining a fluorene compound, a fulvene compound, and at least 2 molar equivalents of KN(SiMe3)2 in any order in the presence of an ether solvent unde...