Ligand-Directed Assembly of Multimetallic Aluminum Complexes: Synthesis, Structure and ROP Catalysis
Por:
García-López J.-D., García-Álvarez A.-C., Hernández-Balderas U., Gallardo-Garibay A., Jancik V., Martínez-Otero D., Moya-Cabrera M.
Publicada:
1 ene 2024
Resumen:
Multinuclear aluminum complexes are useful catalysts for the ring opening polymerization (ROP) of ?-caprolactone (?-CL), often outperforming monometallic analogues in the production of biodegradable polycaprolactone (PCL). These complexes require control over metal-metal distance, ligand structure, and substituents. Herein, we report on the preparation of mono-, bi-, and octametallic aluminum complexes through direct chelation of multidentate bis(phosphino)-2,2-dimethyl-1,3-diamino ligands Me2C[CH2NHR2P(O)]2; R=Ph(1), iPr(2), tBu(3). Ligands 1–3 yielded bimetallic complexes with two types of coordination pockets, as well as bimetallic systems with identical coordination environments. In addition to the diversity of structural patterns within the present series, the catalytic performances of [AlR2{?2-N,N’,–(Me2C{CH2NPh2P(O)}2}-(?2-O,O’-AlR2)] (R=Me(4), Et(5), iBu(6)) outperformed that of the monometallic [AlEt2{?2-O,O’-(Me2C(CH2NtBu2P(O))2H} (10), showing controlled and immortal ROP of ?-CL in the presence of BnOH as co-initiator. DFT calculations suggest that the primary active site for 4–6 is the N-Al–N center. Gaining insight into the underlying principles that lead to high activity and controlled production of PCL in bimetallic systems can help design tailor-made complexes with enhanced performance. © 2024 The Authors. European Journal of Inorganic Chemistry published by Wiley-VCH GmbH.
Filiaciones:
García-López J.-D.:
Centro Conjunto de Investigación en Química Sustentable UAEM-UNAM, Carretera Toluca-Atlacomulco Km 14.5, Toluca, Estado de México, 50200, Mexico
García-Álvarez A.-C.:
Universidad Nacional Autónoma de México, Instituto de Química, Circuito Exterior s/n, Ciudad Universitaria, Cd. Mex, 04510, Mexico
Hernández-Balderas U.:
Centro Conjunto de Investigación en Química Sustentable UAEM-UNAM, Carretera Toluca-Atlacomulco Km 14.5, Toluca, Estado de México, 50200, Mexico
Universidad Nacional Autónoma de México, Instituto de Química, Circuito Exterior s/n, Ciudad Universitaria, Cd. Mex, 04510, Mexico
Gallardo-Garibay A.:
Centro Conjunto de Investigación en Química Sustentable UAEM-UNAM, Carretera Toluca-Atlacomulco Km 14.5, Toluca, Estado de México, 50200, Mexico
Universidad Nacional Autónoma de México, Instituto de Química, Circuito Exterior s/n, Ciudad Universitaria, Cd. Mex, 04510, Mexico
Jancik V.:
Centro Conjunto de Investigación en Química Sustentable UAEM-UNAM, Carretera Toluca-Atlacomulco Km 14.5, Toluca, Estado de México, 50200, Mexico
Universidad Nacional Autónoma de México, Instituto de Química, Circuito Exterior s/n, Ciudad Universitaria, Cd. Mex, 04510, Mexico
Martínez-Otero D.:
Centro Conjunto de Investigación en Química Sustentable UAEM-UNAM, Carretera Toluca-Atlacomulco Km 14.5, Toluca, Estado de México, 50200, Mexico
Universidad Nacional Autónoma de México, Instituto de Química, Circuito Exterior s/n, Ciudad Universitaria, Cd. Mex, 04510, Mexico
Moya-Cabrera M.:
Centro Conjunto de Investigación en Química Sustentable UAEM-UNAM, Carretera Toluca-Atlacomulco Km 14.5, Toluca, Estado de México, 50200, Mexico
Universidad Nacional Autónoma de México, Instituto de Química, Circuito Exterior s/n, Ciudad Universitaria, Cd. Mex, 04510, Mexico
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