Complexation behaviour of LiCl and LiPF6 – model studies in the solid-state and in solution using a bidentate picolyl-based ligand. Issue 87 (23rd October 2020) - Espinosa-Jalapa, Noel Angel
Abstract : Using a new bulky bidentate ligand and combining various structure elucidation methods, coordination modes of [ligand·LiX] (X = Cl, PF6 ) complexes both in solid-state and in solution have been revealed. Abstract : Structural knowledge on ubiquitous lithium salts in solution and in the crystalline state is of paramount importance for our understanding of many chemical reactions and of the electrolyte behaviour in lithium ion batteries. A bulky bidentate Si-based ligand (6 ) was used to create simplified model systems suitable for correlating structures of LiCl and LiPF6 complexes in the solid-state and in solution by combining various experimental, spectroscopic, and computational methods. Solution studies were performed using 1 H DOSY, multinuclear variable temperature NMR spectroscopy, and quantum chemical calculations. [Ph2 Si(2-CH2 Py)2 ·LiCl]2 (3 ) dissociates into a monomeric species (9 ) in THF. For [Ph2 Si(2-CH2 Py)2 ·LiPF6 ]2 (11 ), low temperature NMR studies revealed an unprecedented chiral coordination mode (12 ) in non-coordinating solvents.