Tri‐ and Pentanuclear Complexes Derived from Manganese(III) Schiff Base and Hexacyanoferrate(III) Building Blocks

A tri‐ and a pentanuclear cyanido‐bridged complex based on manganese(III) Schiff base and hexacyanoferrate(III) units, namely, [{Mn(naphtmen)} 2 {Fe(CN) 6 }][Mn(naphtmen)(CH 3 OH) 2 ] 2 ClO 4 · 5CH 3 OH · H 2 O [ 1 ; naphtmen 2– = N , N′ ‐(1,1,2,2‐tetramethylethylene)bis(naphthylideneiminato) dianion] and [{Mn(naphtmen)} 4 {Fe(CN) 6 }]ClO 4 ( 2 ), were synthesized and structurally characterized by X‐ray single‐crystal diffraction. The structural analyses show that 1 consists of linear trinuclear clusters of [{Mn(naphtmen)} 2 {Fe(CN) 6 }] – anions, which are further linked into one‐dimensional chains by the out‐of‐plane biphenolate bridges. In 2 , magnetically isolated cyanido‐bridged pentanuclear {[Mn(naphtmen)] 4 [Fe(CN) 6 ]} + cations were obtained. The temperature‐dependent magnetic susceptibilities indicate that the exchange interactions between the Fe III and Mn III ions through the cyanido bridges are ferromagnetic in 1 and 2 . The magnetic fittings for 1 and 2 gave magnetic coupling constants J MnFe = 6.68 and 4.31 cm –1 , respectively. Complex 2 exhibits a clear frequency‐dependent alternating‐current (AC) magnetic susceptibility below 3.5 K, which is due to single‐molecule magnet behavior with U eff = 23.4 cm –1 and τ 0 = 7.5 × 10 –10 s.