Alkali Metal Based Triimidosulfite Cages as Versatile Precursors for Single‐Molecule Magnets

Based on the potassium [{S( t BuN) 2 ( t BuNH)} 2 K 3 (tmeda)‐K 3 {(HN t Bu)(N t Bu) 2 S} 2 ] ( 1 ) and sodium precursors [S( t BuN) 3 (thf) 3 ‐Na 3 SNa 3 (thf) 3 (N t Bu) 3 S] ( 2 ), [S( t BuN) 3 (thf) 3 Na 3 {(HN t Bu)(N t Bu) 2 S}] ( 3 ) and [(tmeda) 3 S‐{Na 3 (N t Bu) 3 S} 2 ] ( 4 ) the syntheses and magnetic properties of three mixed metal triimidosulfite based alkali‐lanthanide‐metal‐cages [( t BuNH)Dy{K(0.5tmeda)} 2 {(N t Bu) 3 S} 2 ] n ( 5 ) and [ClLn{Na(thf)} 2 {(N t Bu) 3 S} 2 ] with Ln=Dy ( 6 ), Er ( 7 ) are reported. The corresponding potassium ( 1 ) and sodium ( 2 – 4 ) based cages are characterized through XRD and NMR experiments. Preventing lithium chloride co‐complexation led to a significant increase of SMM performance to previously reported sulfur‐nitrogen ligands. The subsequent Dy III ‐complexes 5 and 6 display slow relaxation of magnetization at zero field, with relaxation barriers U =77.0 cm −1 for 5 , 512.9 and 316.3 cm −1 for 6 , respectively. Significantly, the latter complex 6 also exhibits a butterfly‐shaped hysteresis up to 7 K.