High-spin metal–cyanide clusters: species incorporating [Mn(salen)]+ complexes as a source of anisotropy Original Research Article

The use of N,N′-ethylenebis(salycylideneiminato) (salen) complexes of MnIII in assembling high-spin metal–cyanide coordination clusters with significant magnetic anisotropy is demonstrated. The reaction of [Mn(salen)(H2O)2]+with [Cr(CN)6]3− in aqueous solution generates {Cr[CNMn(salen)(H2O)]6}[Cr(CN)6]·6H2O (1), a previously reported compound featuring a heptanuclear cluster with a distorted octahedral geometry. A fit to the variable-temperature magnetic susceptibility data for 1 revealed the presence of weak antiferromagnetic coupling of within the cluster, giving rise to an S=21/2 ground state. In addition, variable-field magnetization data collected at low temperatures revealed the presence of magnetic anisotropy in the ground state, with the best fit yielding zero-field splitting parameters of D=+0.19 cm−1 and A reaction intended to produce a direct analogue of 1 by employing [Fe(CN)6]3− in place of [Cr(CN)6]3− instead gave an unusually complex compound of formula {Fe(CN)4[CNMn(salen)(MeOH)]2}{[Mn(salen)(H2O)]2}[Mn(salen)(H2O)(MeOH)]2[Fe(CN)6]·4H2O (2). The crystal structure and magnetic properties of this compound are reported.