A new bimetallic assembly magnet [[Ni(tn)2]5[FeIII(CN)6]3]n(ClO4)n.2.5nH2O (tn = trimethylenediamine) with a novel 3-D tunnel structure

A novel molecular-based magnet of three-dimensional (3-D) cyanide-bridged bimetallic assembly, Ni(tn)2]5FeII(CN)6]3]n(ClO4)n.2.5nH2O where tn = trimethylenediamine, was synthesized and structurally characterized. The compound with an asymmetric unit of C24H52.5Cl0.5Fe1.5N19Ni2.5O3.255 crystallized in the monoclinic system of the space group P2(1)/n with a = 10.173(3) A, b = 16.053(2) A, c = 26.309(3) A, beta = 91.30(2) degrees, and Z = 4. The assembly has a 3-D network structure extended by three different types of FeIII-CN-NiII-NC-FeIII linkages. The iron (FeIII) atoms are located in two different chemical environments, which were confirmed by M?ssbauer experimental results. The nickel (NiII) atoms have three different coordination environments. Cryomagnetic properties revealed that 3-D magnetic ordering occurs over the lattice below the Curie temperature around 10 K.