Electronic structures of bent lanthanide(III) complexes with two N-donor ligands

• Published in: Chemical science (Cambridge) Vol. 1; no. 45; pp. 1493 - 152
• Main Authors: Nicholas, Hannah M, Vonci, Michele, Goodwin, Conrad A. P, Loo, Song Wei, Murphy, Siobhan R, Cassim, Daniel, Winpenny, Richard E. P, McInnes, Eric J. L, Chilton, Nicholas F, Mills, David P
• Format: Journal Article
• Language: English
• Published: CAMBRIDGE Royal Soc Chemistry 07.12.2019; Royal Society of Chemistry
• Subjects: Chemistry; Chemistry, Multidisciplinary; Coordinates; Coordination compounds; Crystallography; Electronic structure; Lanthanides; Ligands; Magnetic properties; Organic chemistry; Oxidation; Physical Sciences; Science & Technology; Valence; CHEMISTRY; CRYSTAL-STRUCTURES; DESIGN; SILYLAMIDES; DFT; ANISOTROPY
• ISSN: 2041-6520; 2041-6539
• DOI: 10.1039/c9sc03431e

Low coordinate metal complexes can exhibit superlative physicochemical properties, but this chemistry is challenging for the lanthanides (Ln) due to their tendency to maximize electrostatic contacts in predominantly ionic bonding regimes. Although a handful of Ln 2+ complexes with only two monodentate ligands have been isolated, examples in the most common +3 oxidation state have remained elusive due to the greater electrostatic forces of Ln 3+ ions. Here, we report bent Ln 3+ complexes with two bis(silyl)amide ligands; in the solid state the Yb 3+ analogue exhibits a crystal field similar to its three coordinate precursor rather than that expected for an axial system. This unanticipated finding is in opposition to the predicted electronic structure for two-coordinate systems, indicating that geometries can be more important than the Ln ion identity for dictating the magnetic ground states of low coordinate complexes; this is crucial transferable information for the construction of systems with enhanced magnetic properties. Halide abstraction chemistry is performed on a series of trigonal lanthanide(III) complexes to provide bent complexes that contain only two N-donor ligands.