Synthesis, crystal structure and magnetic properties of cyanide-bridged one-dimensional Ni(II)–Fe(III) complexes based on pentacyanoferrite

Four cyanide-bridged bimetallic Ni(II)–Fe(III) complexes have been synthesized and characterized in order to find new molecular materials with interesting magnetic properties. One-dimensional complexes of pentacyanoferrite(III), [Ni(2,3,2-tet)Fe(Him)(CN)5]·3H2O (1), [Ni(3,2,3-tet)][Fe(CN)5(Him)]·2H2O (2), [Ni(3,2,3-tet)][Fe(CN)5(1-CH3im)]·4H2O (3), and [NiL1][Fe(CN)5(1-CH3im)]·3H2O (4) have been prepared and characterized by X-ray single-crystal structure analysis and magnetic measurements. All complexes possesses linear or zigzag chains of alternate [Ni(L′)]2+ and [Fe(L)(CN)5]2− units, which are linked by two trans/cis cyanide ligands of [Fe(L)(CN)5]2−. Magnetic studies reveal that they exhibit intermetallic ferromagnetic coupling and long-range antiferromagnetic ordering. The strength of the Ni(II)–Fe(III) magnetic coupling has been analyzed by comparison with the related cyanide-bridged Ni(II)–Fe(III) complexes.

[Fe(CN)5(L)]2− (L = imidazole or 1-methylimidazole) have been used for the first time to construct cyanide-bridged 1D Ni(II)–Fe(III) complexes. Ferromagnetic interaction between FeIII and NiII was observed, and the strength of the magnetic coupling has been found to be related to the Ni–Ncyano bond distances and Ni–NC bond angles.Figure optionsDownload as PowerPoint slide