Crystal structure and magnetic properties of [{Cu(cyclam)}3{Fe(CN)6}2] · 6H2O, a cyano-bridged assembly with a rope-ladder chain structure

The title complex is made up of centrosymmetric S-shaped pentanuclear [{Cu(cyclam)}3{Fe(CN)6}2] units, held together by two weak and complementary Fe-CN⋯Cu bonds to form a rope-ladder chain. Interestingly enough, the ferromagnetic interaction between Cu(II) and Fe(III) ions through the long Cu-N axial bonds is not so weak as is usually assumed.