In this work, the isolation of compounds containing the [Dy{N(Si i Pr)3}2] + cation has realized a longstanding goal to synthesize a formally two-coordinate Dy(III) complex, allowing the magnetic properties of this new class of SMM to be determined. We have found a larger than predicted effect of the N-Dy-N angle on SMM behavior, with the significantly bent geometry of [Dy{N(Si i Pr)3}2] + resulting in relatively low-lying and highly mixed excited mJ states. Frozen solution magnetic data indicate a species with substantially slower relaxation dynamics, suggesting that a more linear N-Dy-N angle can be adopted in this phase, but this could not be unambiguously confirmed. We propose that fast magnetic relaxation in [Dy{N(Si i Pr)3}2] + arises from a combination of its large deviation from linearity and the flexible coordination environment, in accord with the rigidity of coordinated ligands being of equal importance to the control of molecular geometry for SMMs to show high blocking temperatures. complexes. Single crystal XRD data were collected on either an Oxford Diffraction Agilent Supernova profile was applied for all structures. The structures were solved using SHELXT; 60 the datasets were refined by full-matrix least-squares on all unique F 2 values. Anisotropic displacement parameters were used for all non-hydrogen atoms with constrained riding hydrogen geometries, with the exception of borohydride H atoms, which were located in the difference map and refined isotropically; Uiso(H) was set were close to heavy atoms and were of no chemical significance. CrysAlisPro was used for control and integration, and SHELX was employed through OLEX2 for structure solution and refinement.