Syntheses, structures, and magnetic properties of cyano- and phenoxide-bridged Fe(iii)-Mn(iii) tetrameric assemblies formed by blocked fac-Fe tricyanide with aliphatic rings

Three tetranuclear clusters [(Tp^Me,mt3)Fe(CN) ₃Mn(L)]₂ (1, L = 5-Clacphmen; 2, L = 5-Clsalen; 3, L = 5-MeOsalen; Tp^Me,mt3 = hydrotris(3-methyl-4,5-propylene-5- methylpyrazol-1-yl)borate) were prepared by assembling the fac-Fe tricyanide with the corresponding Mn Schiff bases. The assembled molecules are linked by cyanide and phenoxide bridges. Weak π-π contacts between molecules are evident in these clusters. Compounds 1-3 exhibit slow relaxation of the magnetization. The phenoxide linkers mediate ferromagnetic coupling between the Mn centers, which is ascribed to the long axial Mn-O* length. The overall magnetic exchange coupling nature of the Fe-CN-Mn route is accounted for by the important structural parameters of bridging pathways such as Mn-N _cyano length, Mn-N_cyano-C_cyano angle, and C_eq-Fe⋯Mn-N_eq (eq = equatorial) torsion angle.