Low-coordinate rare-earth and actinide complexes

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

“…The remarkable optical, magnetic and catalytic properties of the lanthanides (Ln) have provided numerous technological applications, 1 and design criteria now exist to build complexes with precise geometrical features that maximize these attributes. [2][3][4][5][6][7][8][9][10] Highly axial Ln 3+ complexes have recently become desirable targets for the single-molecule magnet (SMM) community as such geometries can provide maximum anisotropy for several Ln 3+ ions; [2][3][4][5][11][12][13] indeed, we have previously predicted that a hypothetical near-linear Dy 3+ cation [Dy{N(Si i Pr 3 ) 2 } 2 ] + could exhibit a record energy barrier to the reversal of magnetization, providing the inspiration for this work. 14 Some of us [15][16][17][18] and others 19,20 have recently shown that isolated axial Ln 3+ metallocenium cations [Ln(Cp R ) 2 ] + (Cp R ¼ substituted cyclopentadienyl) can be prepared by halide abstraction from [Ln(Cp R ) 2 (X)] precursors by using the silylium reagent [H(SiEt 3 ) 2 ][B(C 6 F 5 ) 4 ].…”

“…The isolation of low coordinate Ln complexes is oen synthetically challenging, as the predominantly ionic bonding regimes in these systems favour high coordination numbers to maximize the number of electrostatic interactions between ligand donor atoms and relatively large Ln cations. 8 Seminal work by Bradley in the early 1970s provided the trigonal pyramidal Ln complexes, [Ln{N(SiMe 3 ) 2 } 3 ], which exhibit additional Ln/Cg-Sib interactions that stabilize the coordinatively unsaturated Ln 3+ centres. 23,24 In the interim, numerous trigonal pyramidal and planar Ln 3+ and Ln 2+ complexes have been accessed by using a combination of sterically demanding ligands and strict anaerobic conditions.…”

Co-crystallization of red emitting (NH4)3Sc(SO4)3:Eu3+ microfibers: structure–luminescence relationship for promising application in optical thermometry

“…Therefore, CN = 6 is typical for Sc 3+ in the most of scandium-containing compounds. 33 For Sc 3+ ions, coordination numbers of 7 and 8 are frequently found, but higher coordination numbers often exist as well.…”

Rare Earth Starting Materials and Methodologies for Synthetic Chemistry

“…This step-change in RE chemistry was also propelled by the many advances in anaerobic manipulation techniques and ligand design, which in turn led to discoveries that challenged common assumptions and opened unexpected research avenues. 7 , 10 …”

“…The Organometallic Chemistry of the Lanthanide Elements in Low Oxidation States; 1987 (ref ( 40 )) Edelmann, F. T. Scandium, Yttrium, and the Lanthanide and Actinide Elements, Excluding their Zero Oxidation State Complexes; 1995 (ref ( 6 )) Edelmann, F. T. Lanthanides and Actinides; 1997 (ref ( 9 )) Anwander, R. Principles in Organolanthanide Chemistry; 1999 (ref ( 8 )) Anwander, R. Herrmann, W. A. Features of Organolanthanide Complexes; 2005 (ref ( 39 )) Liddle, S. T. Lanthanides: Organometallic Chemistry Fundamental Properties; 2012 (ref ( 41 )) Nicholas, H. M.; Mills, D. P. Lanthanides: Divalent Organometallic Chemistry; 2017 (ref ( 42 )) Ortu, F.; Mills, D. P. Low Coordinate Rare Earth and Actinide Complexes; 2019 (ref ( 7 )) Layfield, R. A. Lanthanides; 2021 (ref ( 43 )) …”