Bimetallic assemblies [Ni(L)2]3[Fe(CN)6]X2(L=ethylenediamine, trimethylenediamine;: X=PF6-, ClO4-) with a three-dimensional network extended through FeII-CN-NiII linkages

Three-dimensional cyanide-bridged bimetallic assemblies [Ni(L)(2)](3)[Fe-II(CN)(6)]X-2 ((L,X) = (ethylenediamine (en), PF6-) (1), (trimethylenediamine (tn), PF6-) (2), (tn, ClO4-) (3)) were synthesized and structurally characterized. Compounds 1-3 crystallize in the trigonal system of the space group R (3) over bar with a = b = 13.743(1) Angstrom, c = 17.802(2) Angstrom, and Z = 3 for 1, a = b = 14.588(1) Angstrom, c = 17.050(2) Angstrom, and Z = 3 for 2, and a = b = 14.337(2) Angstrom, c = 17.294(4) Angstrom, and Z = 3 for 3. All the assemblies have an isotropic three-dimensional network structure extended through Fe-CN-Ni linkages. The network is based on a cube formed by 8 [Fe(CN)(6)](4-) anions at the corners and 12 [Ni(L)(2)](2+) cations at the edges. Two hexafluorophosphate or perchlorate anions are located in the cavity of the Fe8Ni12 cube and align along a diagonal axis that coincides with the c axis. Magnetic measurements show a ferromagnetic interaction between the nearest Ni-II ions through the diamagnetic Fe-II ion.