Synthesis, Crystal Structures, and Magnetic Properties of Two Tetrahedral Mn II Mn III 3 Complexes

Two tetranuclear manganese complexes, [NaMn II Mn 3 III (μ 4 ‐O 2– )(HL) 3 (SCN) 4 ] ( 1 ) and [NaMn II Mn 3 III (μ 4 ‐O 2– )(HL) 3 Cl 4 ][NaMn II Mn 3 III (μ 4 ‐O 2– )(HL) 3 Cl 3 (H 2 O)]ClO 4 · 3.5H 2 O ( 2 ) were obtained from the reaction of manganese perchlorate with a quadridentate Schiff base ligand, 3‐(2‐hydroxybenzylideneamino)propane‐1, 2‐diol (H 3 L) derived from condensation of 2‐hydroxybenzaldehyde with 3‐amino‐1, 2‐propanediol, as well as the coligand KSCN or NaCl under basic conditions. Single‐crystal X‐ray studies reveal that those two complexes all have a mixed‐valent tetrahedral core, which contains an apical Mn II ion and three basal Mn III ions situated in the [Mn 3 (μ 4 ‐O 2– )] 7+ equilateral triangle plane. Fitting of the magnetic susceptibility data to the theoretical χ m T vs. T expression, revealed that the presence of only antiferromagnetic interactions between the central metal atoms in 1 , while both antiferromagnetic and ferromagnetic interactions are present in 2 .