Single-Molecule-Magnet Behavior and Spin Changes Affected by Crystal Packing Effects

Five Mn3Zn2 heterometallic complexes have been synthesized and structurally and magnetically characterized. Spin ground states up to S = 6 have been observed for these complexes and are shown to depend on the cocrystallizing cation and on the terminal ligand. Large axial zero-field interactions (D = −1.16 K) are the result of near-parallel alignment of the MnIII Jahn−Teller axes. High-frequency electron paramagnetic resonance, single-crystal magnetization hysteresis, and alternating current susceptibility measurements are presented to characterize [NEt4]3[Mn3Zn2(salox)3O(N3)6X2] [X− = Cl− (1), Br− (2)] and [AsPh4]3[Mn3Zn2(salox)3O(N3)6Cl2] (3) and reveal that 1 and 2 are single-molecule magnets (Ueff = 44 K), while 3 is not.