Evidence for Methylaluminoxane (MAO) Molecular Structure and Reactivity from Ultrahigh Magnetic Field <sup>27</sup> Al MAS NMR Spectroscopy Combined with DFT Calculations
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 <sup>1</sup>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<sub>2</sub>Me<sub>2</sub>], 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.
Authors
- Eva Zurek (ORCID: https://orcid.org/0000-0003-0738-867X)
- Jochen Autschbach (ORCID: https://orcid.org/0000-0001-9392-877X)
- Mostafa Taoufik (ORCID: https://orcid.org/0000-0002-3627-5263)
- Laurent Delevoye (ORCID: https://orcid.org/0000-0003-3146-9365)
- Julien Trébosc (ORCID: https://orcid.org/0000-0002-4034-855X)
- Régis Michaël Gauvin (ORCID: https://orcid.org/0000-0002-4788-4363)
- Franck Fayon (ORCID: https://orcid.org/0000-0001-5086-5625)
- David Gajan (ORCID: https://orcid.org/0000-0002-0182-1674)
- Kai C. Szeto
Institutions
- Université Claude Bernard Lyon 1 (FR)
- Buffalo State University (US)
- Université d'Orléans (FR)
- Centre National de la Recherche Scientifique (FR)
- Chimie ParisTech - PSL (FR)
- Université de Lille (FR)
- Université Paris Sciences et Lettres (FR)
- Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement (FR)
- Institut de Recherche de Chimie Paris (FR)
- Laboratoire de Spectrométrie Ionique et Moléculaire (FR)
- Conditions Extrêmes et Matériaux Haute Température et Irradiation (FR)
- Unité de catalyse et de chimie du solide de Lille (FR)
- Université d'Artois (FR)
- École d'Ingénieurs en Chimie et Sciences du Numérique (FR)
- University at Buffalo, State University of New York (US)
- École Centrale de Lille (FR)
Publication Details
- Journal
- Angewandte Chemie International Edition
- Published
- 2025-05-23
- DOI
- https://doi.org/10.1002/anie.202508409
- Citations
- 8
- Primary Topic
- Advanced NMR Techniques and Applications
- Type
- article
- Field-Weighted Citation Impact
- 6.05
Funders
- Centre National de la Recherche Scientifique
- Région Hauts-de-France
- Institut Chevreul