Evidence for Methylaluminoxane (MAO) Molecular Structure and Reactivity from Ultrahigh Magnetic Field 27 Al MAS NMR Spectroscopy Combined with DFT Calculations
Year: 2025
Type: article
Abstract: The structure and reactivity of methylaluminoxane (MAO), a reagent of major interest for olefin polymerization, both industrially and academically, has been probed using ultrahigh magnetic field solid‐state NMR (28.2 T, 1200 MHz for 1 H Larmor frequency). High resolution methods combined with density functional calculations allowed for the identification and quantification of five major aluminum sites, providing precise information on the structure of MAO at the molecular level. Based on reactivity studies with THF and [ZrCp 2 Me 2 ], the main reactive centers are identified as bismethyl aluminum species stabilized via a bridging methyl group from a neighboring Al center, featuring both high chemical shift and quadrupolar coupling constants (162 ppm and 27.4 MHz, respectively). This approach demonstrates the ability to monitor the chemistry of MAO with unprecedented precision, enabling a state‐of‐the‐art understanding of its structure and reactivity.
Institutions: Lyon 1 Université, Centre National de la Recherche Scientifique, Catalyse, Polymérisation, Procédés et Matériaux, École d'Ingénieurs en Chimie et Sciences du Numérique, Université d'Orléans, Conditions Extrêmes et Matériaux Haute Température et Irradiation, École Normale Supérieure de Lyon, Centre de RMN à Très Hauts Champs de Lyon, Buffalo State University, University at Buffalo, State University of New York, Université de Lille, Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement, Institut Michel-Eugène Chevreul, Unité de Catalyse et Chimie du Solide, Chimie ParisTech - PSL, Institut de Recherche de Chimie Paris
Language: English
Subfield: Organic Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $5,510
OpenAlex ID: W4410695612