Raising the temperatures at which single-molecule magnets (SMMs) exhibit magnetic remanence is key to unlocking their potential applications in high-density data storage, as the liquid helium cooling currently required is expensive. For the last two decades lanthanide (Ln) SMMs have shown the most promise to achieve this goal, with axial dysprosium complexes predicted to show the highest energy barriers to magnetic reversal (Ueff). As the isolation of an ideal axial two-coordinate linear Dy(III) complex is a major synthetic challenge, pentagonal bipyramidal Dy complexes with strongly donating apical alkoxides and five weak equatorial donor ligands were the first SMMs to achieve Ueff values > 1000 K. Salts with axial dysprosocenium cations [Dy(Cp R )2] + (Cp R = substituted cyclopentadienyl) and related derivatives subsequently raised 100 s magnetic blocking temperatures (TB) ever-closer to the boiling point of liquid nitrogen (77 K); this was attributed to the rigidity of the coordinated aromatic ligands hindering Raman magnetic relaxation pathways. The current record-holding SMM [Dy2(C5 i Pr5)2(μ-I)3] contains a 1e - Dy-Dy bond, and has Ueff = 2345 (36) K and TB = 72 K. Prior to the isolation of these high-barrier SMMs, some of us reported the syntheses of the nearlinear Ln complexes [Ln{N(Si i Pr3)2}2] (Ln = Sm, Eu, Tm, Yb). We used the experimentally-determined atomic coordinates of the Sm(II) derivative (N-Ln-N: 175. 5(2)°) to calculate that an analogous Dy(III) bis(amide) cation [Dy{N(Si i Pr3)2}2] + could show Ueff ≈ 2600 K; this value was over triple the magnitude of the record barrier for Dy SMMs at the time (842 K for a polymetallic Dy-doped yttrium alkoxide complex). Further calculations revealed that Ueff values could remain > 1300 K even if the N-Dy-N angle was reduced to as low as 120°, provided that no additional ligands coordinated. In the interim, we synthesized the bent Ln(III) bis(amide) complexes [Ln{N(Si i Pr3)2}2][B(C6F5)4] for Ln = Sm, Tm and Yb, using the parent Ln(II) complexes [Ln{N(Si i Pr3)2}2] as starting materials; recently, a related bent Yb(III) bis(amide) complex, [Yb{N(SiPh2Me)2}2][Al{OC(CF3)3}4], has been reported. However, due to synthetic difficulties associated with installing bulky silylamides at small, charge-dense Ln(III) centers, we had previously been unable to access the desired Dy(III) bis(amide) cation [Dy{N(Si i Pr3)2}2] + . Indeed, the isolation of any Dy complex containing only two monodentate ligands has proved elusive for the wider synthetic chemistry community to date, which is particularly hampered by the predominantly ionic bonding regimes of relatively large Ln cations favoring higher coordination numbers (CNs). Here we report the isolation and characterization of the bent Dy bis(amide) complex [Dy{N(Si i Pr3)2}2][Al{OC(CF3)3}4] (1-Dy), together with the diamagnetic yttrium analog 1-Y, and other complexes that were prepared as starting materials to these synthetic targets. Magnetic measurements reveal that the SMM properties of 1-Dy are not as advantageous as originally predicted. Ab initio calculations show that the bent geometry still imposes very large magnetic anisotropy in 1-Dy, as large as for the first dysprosocenium cation [Dy(Cp ttt )2] + . As molecular rigidity has been shown to be crucial for controlling spin-phonon relaxation in dysprosocenium cations, we propose that the flexible coordination environment in 1-Dy enables rapid magnetic relaxation; the large magnetic anisotropy generated by crystal field (CF) splitting will therefore not necessarily result in a high-barrier Ln SMM unless spin-phonon relaxation enabled by molecular vibrations is adequately controlled.