Synthesis and Evaluation of Trialkyl Ammonium Tetrakis(perfluorophenyl) Aluminate, a Highly Efficient Activator for High-Temperature Ethylene-α-Olefin Copolymerization Reactions

• Published in: Organometallics Vol. 43; no. 20; pp. 2651 - 2661
• Main Authors: Bremer, Sean, Bellair, Robert J., Scholtz, Travis W., Senecal, Todd D., Klosin, Jerzy
• Format: Journal Article
• Language: English
• Published: American Chemical Society 28.10.2024
• ISSN: 0276-7333; 1520-6041
• DOI: 10.1021/acs.organomet.4c00268

The new salt, [HNMe­(C18H37)2]­[Al­(C6F5)4], was prepared and was shown to be highly effective as an activator for Group IV precatalysts in high-temperature ethylene-1-octene copolymerization reactions. The performance of this activator closely mirrors that of the state-of-the-art activator borate-based analogue. Unlike the borate analogue, the aluminate activator reacts readily with water at ambient temperature, generating pentafluorobenzene, the only fluorine-containing product. Such a feature might be helpful when preparing polymers without any charged contaminants. Unlike some of the other aluminum compounds containing perfluorophenyl groups, [HNMe­(C18H37)2]­[Al­(C6F5)4] was found not to be impact-sensitive and is stable at ambient temperature for months. Detailed evaluation of this aluminate salt and several other aluminum alkyls/aryls (e.g., Al­(C6F5)3(THF), Al­(C6F5)3, AlEt3, and MMAO-3A) was carried out to evaluate their reactive chemistry and safety profiles.