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), PF 6 - ) ( 1 ), (trimethylenediamine (tn), PF 6 - ) ( 2 ), (tn, ClO 4 - ) ( 3 )) were synthesized and structurally characterized. Compounds 1 − 3 crystallize in the trigonal system of the space group R 3̄ with a = b = 13.743(1) Å, c = 17.802(2) Å, and Z = 3 for 1, a = b = 14.588(1) Å, c = 17.050(2) Å, and Z = 3 for 2, and a = b = 14.337(2) Å, c = 17.294(4) Å, 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 Fe 8 Ni 12 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.