Cationic group 1 carbodiphosphorane complexes

• Published in: Polyhedron Vol. 196; p. 115014
• Main Authors: Münzer, Jörn E., Sieg, Grégoire H.R., Vehlies, Robert, Fuzon, Patrick A., Xie, Xiulan, Neumüller, Bernhard, Kuzu, Istemi
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.03.2021
• Subjects: Carbodiphosphorane; Lithium; NMR; Sodium; X-Ray; X-Ray; Lithium; NMR; Carbodiphosphorane; Sodium
• ISSN: 0277-5387
• DOI: 10.1016/j.poly.2020.115014

We present the first examples of carbodiphosphorane (CDP) complexes with alkali metal cations (Li+ and Na+). The homoleptic CDPR stabilized Li and Na cations, respectively, were isolated as tris(silylamido) ferrates in the solid state. In solution, a chemical exchange process in the Li+ and Na+ complexes are at hand. [Display omitted] •First examples of carbodiphosphorane (CDP) complexes with alkali metal cations (Li+ and Na+) were synthesised.•Coordination sphere of the cationic group 1 center is provided by two CDP ligands.•Li+ and Na+ complexes are in equilibrium with the starting materials in solution (chemical exchange process). Reactions of carbodiphosphorane (CDPR) ligands with equimolar quantities of group 1 and Fe(II) bis(trimethylsilyl)amides result in the isolation of discrete CDP-stabilized ion pairs, [M(CDPR)2]+[Fe{N(SiMe3)2}3]− (M = Li, Na; R = hexaphenyl, cyclopropyl-tetraphenyl). X-ray diffraction analysis revealed that the coordination sphere of the cationic group 1 center is provided by two CDPR ligands. In the solid state, we investigated the influence of the ligand substituents on the resulting architecture of the title complexes by utilizing different CDP ligands. In solution, we examined the stability of these complexes by variable temperature NMR spectroscopy. This study revealed that all title complexes show lability in solution due to dynamic processes: they are subject to a chemical exchange with the corresponding starting materials.