Syntheses, structures and magnetic properties of heterobimetallic complexes based on a new tetracyanometalate precursor

A new mononuclear tetracyanometallic complex, (n-Bu4N)[(dbphen)Fe(CN)4] (1, dbphen = 5,6-dibromo-1,10-phenanthroline), has been prepared by reacting [(dbphen)FeII(py)2(SCN)2] and KCN in water and further oxidized with chlorine. With the use of 1 as building block, two trinuclear Fe2M complexes, [(dbphen)2Fe2(CN)8Cu(Me3tacn)]·3H2O (2), [(dbphen)2Fe2(CN)8Ni(dabhctd)]·2H2O (3) and a chain complex of squares [(dbphen)2Fe2(CN)8Co(MeOH)2]n (4), have been synthesized and structurally characterized. Magnetic studies show ferromagnetic coupling between FeIII and MII (M = Cu, 2; Ni, 3) ions bridged by cyanides in complexes 2 and 3, while complex 4 exhibits meta-magnetic behavior.