Molecular Engineering for Single‐Chain‐Magnet Behavior in a One‐Dimensional Dysprosium–Nitronyl Nitroxide Compound

Single-chain magnets: A rational approach to decrease magnetic dipolar interactions led to the chain compound Dy (hfac) 3NIT (C6H4OPh) (see structure; NIT (R): 2- (4′-R) -4, 4, 5, 5-tetramethylimidazoline-1-oxyl-3-oxide), the first rare-earth-radical-based single-chain magnet. The compound shows slow relaxation behavior, a dynamical crossover resulting from finite-size effects, and a very rich static magnetic behavior.