Lanthanide (Ln) compounds often exhibit fascinating properties, 1 and low coordinate Ln complexes with precise geometries can display enhanced optical and magnetic behavior due to the influence of the crystal field (CF) on electronic structures. Coordinatively unsaturated Ln complexes are often challenging to synthesize as large Ln cations exhibit predominantly electrostatic bonding with ligands, promoting high coordination numbers. Sterically demanding ligands can be used to saturate Ln coordination spheres; however, heteroleptic low-coordinate Ln complexes are still relatively scarce due to facile Schlenk-type equilibria, therefore advances in ligand design are required to prepare larger families of these complexes to define their electronic structures. Bis(silyl)amides have proved to be particularly adept at stabilizing low coordinate Ln complexes as they combine relatively hard N-donor atoms with numerous additional Ln•••Cγ-Siβ electrostatic interactions. The near-linear Ln 2+ complexes [Ln{N(Si i Pr3)2}2] (1-Ln, Ln = Sm, Eu, Tm, Yb) were synthesized by salt metathesis methods; the single electron transfer (SET) reaction of 1-Sm with 2,2,6,6-tetramethylpiperidinyl-1-oxy radical (TEMPO • ) gave the approximately trigonal planar Sm 3+ complex [Sm{N(Si i Pr3)2}2(TEMPO)] (2-Sm), where the resultant TEMPO -anion exhibits a κ 1 -O binding mode. While Ln radical compounds and their magnetic properties have been studied for many years, including an early single chain magnet and as single-molecule magnets (SMMs), there are only a handful of structurally characterized TEMPO • radicals coordinated to Ln 3+ centers. -24 TEMPO • has been most commonly employed in low oxidation state f-block chemistry as an oxidant to deliver O or TEMPO -anions. Of most relevance here, in 2012 Evans and co-workers reported that the oxidation of [{Y[N(SiMe3)2]2(THF)}2(µ,η 2 :η 2 -N2)]2 with TEMPO • yielded the Y 3+ bis(silyl)amide complex [Y{N(SiMe3)2}2(η 2 -TEMPO)(THF)], which exhibits a TEMPO -anion binding side-on via both oxygen and nitrogen atoms. More recently, some of us disclosed the syntheses of the bent Ln 3+ complexes [Ln{N(Si i Pr3)2}2][B(C6F5)4] (3-Ln; Ln = Sm, Dy, Tm, Yb). We envisaged that 3-Ln would be bound more readily by Lewis bases than 1-Ln due to a combination of more accessible reactive sites provided by their bent geometries and more Lewis acidic Ln centers. Here we report the synthesis of approximately trigonal planar Ln 3+ complexes, [Ln{N(Si i Pr3)2}2(TEMPO)]