A lithium–aluminium heterobimetallic dimetallocene

• Published in: Nature chemistry Vol. 16; no. 7; pp. 1093 - 1100
• Main Authors: Bischoff, Inga-Alexandra, Danés, Sergi, Thoni, Philipp, Morgenstern, Bernd, Andrada, Diego M., Müller, Carsten, Lambert, Jessica, Gießelmann, Elias C. J., Zimmer, Michael, Schäfer, André
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01-07-2024; Nature Publishing Group
• Subjects: 639/638/263/406/910; 639/638/263/910; 639/638/911/406/910; Aluminum; Analytical Chemistry; Biochemistry; Carbenes; Chemistry; Chemistry and Materials Science; Chemistry/Food Science; Inorganic Chemistry; Ligands; Lithium; Magnetic resonance spectroscopy; NMR spectroscopy; Organic Chemistry; Physical Chemistry; Single crystals; Structural analysis; X-ray diffraction
• ISSN: 1755-4330; 1755-4349; 1755-4349
• DOI: 10.1038/s41557-024-01531-y

Homobimetallic dimetallocenes exhibiting two identical metal atoms sandwiched between two η
5
bonded cyclopentadienyl rings is a narrow class of compounds, with representative examples being dizincocene and diberyllocene. Here we report the synthesis and structural characterization of a heterobimetallic dimetallocene, accessible through heterocoupling of lithium and aluminylene fragments with pentaisopropylcyclopentadienyl ligands. The Al–Li bond features a high ionic character and profits from attractive dispersion interactions between the isopropyl groups of the cyclopentadienyl ligands. A key synthetic step is the isolation of a cyclopentadienylaluminylene monomer, which also enables the structural characterization of this species. In addition to their structural authentication by single-crystal X-ray diffraction analysis, both compounds were characterized by multinuclear NMR spectroscopy in solution and in the solid state. Furthermore, reactivity studies of the lithium–aluminium heterobimetallic dimetallocene with an N-heterocyclic carbene and different heteroallenes were performed and show that the Al–Li bond is easily cleaved.
Dimetallocenes are a narrow class of compounds represented by the homobimetallic examples dizincocene and diberyllocene. Now a heterobimetallic dimetallocene featuring lithium and aluminium centres has been synthesized. The Al–Li bond is shown to cleave upon reaction with N-heterocyclic carbenes and heteroallenes.