A New Family of Homo‐ and Heterometallic Manganese Complexes at High Oxidation States Derived from the Oxidation of Mn II with Ce IV : Syntheses, Structures, and Magnetic Properties

A series of homo‐ and heterometallic manganese(III or IV) clusters, [Mn 2 O 2 (pybim) 4 ](NO 3 ) 4 · 11H 2 O [ 1 ; pybim = 2‐(2‐pyridyl)benzimidazole], [Mn 3 O 4 (bipy) 4 (H 2 O) 2 ][Ce(NO 3 ) 5 (H 2 O)][NO 3 ] 2 · 2H 2 O ( 2 ; bipy = 2,2′‐bipyridine), [Mn 2 Ce 3 O 6 (pta) 6 (NO 3 ) 2 (dmf) 4 ] · H 2 O ( 3 ; Hpta = p ‐toluic acid), and [Mn 8 CeO 8 (pta) 12 (dmf) 4 ] ( 4 ), were prepared by the reaction of simple Mn 2+ salts with (NH 4 ) 2 [Ce(NO 3 ) 6 ] under different experimental conditions. The single‐crystal X‐ray diffraction analyses established that these complexes possess inorganic cores that have various structural topologies, which range from the [Mn 2 O 2 ] 4+ rhomb, a Mn 3 triangle within [Mn 3 O 4 ] 4+ , and the nonplanar [Mn 8 O 8 ] 8+ loop that centrally traps a Ce 4+ ion to the [Mn 2 Ce 3 O 6 ] 8+ cage that contains a Mn 2 Ce 3 trigonal bipyramid. The solid‐state magnetic susceptibility studies revealed that these four complexes possess distinctly different magnetic properties, namely, both 1 and 2 show strong antiferromagnetic interactions between the Mn IV centers, whereas 3 is weakly antiferromagnetic, and 4 , however, has predominantly ferromagnetic interactions.