Design of single cyanide-bridged tetranuclear bimetallic rectangles exhibiting ferromagnetic coupling

The cyanide-bridged tetranuclear bimetallic rectangles (XPh4)4[Fe2IIICu2II(μ-CN)4(CN)8(L)2]·nH2O [X = P (1) and As (2); L = bpcam (1) and bpca (2); n = 4 (1) and 0 (2)] have been prepared and characterized by X-ray diffraction; 1 exhibits intramolecular ferromagnetic interactions leading to a low-lying quintet spin state.