Structural Patterns and Forms of Aggregation of Metallated Diamido Donor Ligands upon Going from Lithium to Thallium(I)

• Published in: European journal of inorganic chemistry Vol. 2000; no. 12; pp. 2577 - 2583
• Main Authors: Galka, Christian H., Trösch, Dominique J. M., Schubart, Martin, Gade, Lutz H., Radojevic, Sanja, Scowen, Ian J., McPartlin, Mary
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag GmbH 01.12.2000; WILEY‐VCH Verlag GmbH
• Subjects: Lithium / Amides; N ligands / Structure elucidation; Thallium
• ISSN: 1434-1948; 1099-0682
• DOI: 10.1002/1099-0682(200012)2000:12<2577::AID-EJIC2577>3.0.CO;2-J

Two polyfunctional lithium amides, [(2‐C5H4N)C(CH3){CH2N(Li)SiMe2R}2]2 [R = Me (3), tBu (4)], have been synthesized and structurally characterized by X‐ray crystallography. They were found to have dimeric structures containing ladder‐type Li−N arrangements in which the form of aggregation and thus folding of the ladder appears to be influenced by the steric demand of the N‐bonded silyl groups. Substitution of the lithium ions by thallium(I) was achieved in two steps, yielding the mixed metal amide [(2‐C5H4N)C(CH3){CH2N(Li)SiMe3}{CH2N(Tl)SiMe3}]2 (5) and the thallium(I) diamide [(2‐C5H4N)C(CH3){CH2N(Tl)SiMe3}2]2 (6). X‐ray diffraction studies of both compounds revealed a dimeric ring structure through Li−N links for the former, while the latter is monomeric and only weakly aggregated in the crystal structure through a short, unsupported thallium(I)−thallium(I) contact of 3.500(2) Å.