Cyano-bridged MnIII3MIII (MIII = Fe, Cr) complexes:: Synthesis, structure, and magnetic properties

Two cyano-bridged tetranuclear complexes composed of Mn(Ill) salen (salen = N,N'-ethylene bis(salicylideneiminate)) and hexacyanometalate(III) (M = Fe, Cr) in a stoichiometry of 3:1 have been selectively synthesized using {NH2(n-C12H25)(2)}(3)[M-III(CN)(6)] (M-III = Fe, Cr) starting materials: [{Mn(salen)(EtOH)}(3){M(CN)6}] (M = Fe, 1; Cr, 2). Compounds 1 and 2 are isostructural with a T-shaped structure, in which [M(CN)6](3-) assumes a meridional-tridentate building block to bind three [Mn(salen)(EtOH)](+) units. The strong frequency dependence and observation of hysteresis on the field dependence of the magnetization indicate that 1 is a single-molecule magnet.