From dimer to trimer zirconium complexes. Insights into the Electron-Rich framework Provided by the Asymmetric Zr3O2Cl5 core

• Published in: Inorganic chemistry communications 2024-12, Vol.170, p.113331, Article 113331
• Main Authors: Dibdalli, Yuvaraja, Morales-Verdejo, Cesar, Muñoz-Castro, Alvaro, Molins, Elies, Amshumali, Mungalimane K.
• Format: Article
• Language: English
• Subjects: Computational analysis; Electron-rich framework; Hydrolysis; Magnetic susceptibility; Sodium amalgam reduction; Zirconium
• ISSN: 1387-7003
• DOI: 10.1016/j.inoche.2024.113331

[Display omitted] •Synthesized novel zirconium dimer and trimer complexes.•Dimeric complexes formed via reduction with sodium amalgam.•Trinuclear complexes obtained through hydrolysis with water.•Structures determined using X-ray diffraction.•Computational analysis elucidated steric repulsion’s role and Zr-ligand interaction variations. This contribution presents novel zirconium dimer and trimer complexes. Reduction of the starting complex, [{(η5-C5Me5) ZrCl2}2-as-Ic] (where, as-Ic = 1,8-dihydro-as-indacene, and η5-C5Me5 = pentamethylcyclopentadiene), using sodium amalgam (Na/Hg (0.5 %)) yielded a dimeric zirconium complex, [{(η5-C5Me5)Zr(μ2-Cl)}2-as-Ic] (1). Subsequent treatment of complex (1) with hydrolyzed water (H2O) in toluene produced a trinuclear zirconium complex, [{(η5-C5Me5) Zr(μ2-Cl)2)}3(μ3-O)(µ-OH)] (2), featuring bridging chloride ions and oxygen ligands, with hydroxide formation. The structures of complexes (1) and (2) were determined using X-ray diffraction methods. Computational analysis of two isomers of (2) elucidated the role of steric repulsion in determining the experimentally characterized structure. The Zr-ligand interaction displayed variation in Zr-C5Me5 coordination upon charge variation from Zr(IV) → Zr(III) → Zr(IV) in the precursor ([{(η5-C5Me5) ZrCl2}2-as-Ic]), (1), and (2). In (2), a well-defined electron-rich region above the central oxygen atom in the Zr3 framework is localized, providing suitable characteristics for further exploration of active catalytic sites.