Heterometallic complexes combining [MnIII(salpn)]+ and [Fe(CN)6]4- units as the products of reactions between [MnIII(salpn)(H2O)C(CN)3] and [Fe(CN)6]3-/4-

The reaction of [Fe(III)(CN)(6)](3-) with neutral [Mn(salpn)(H2O)C(CN)(3)] (salpn: N,N'-propylenebis(salicylideneiminato)) (1) produces two new heterometallic complexes [{Mn-III(salpn)(H2O)}(2){Mn-III(salpn)(H2O)(0.7)(CH3OH)(0.3)}(2)Fe-II(CN)(6)]center dot n(H2O/CH3OH) (2) and [{Mn-III(salpn)}(4){Mn-III(salpn)(H2O)}(2)Fe-II(CN)(6)]{C(CN)(3)}(2)center dot 4H(2)O (3), which are characterized by single-crystal X-ray diffraction. In this reaction, the [C(CN)3](-) ligand reduces Fe(III) to Fe(II). Complex 3 can be prepared directly using hexacyanoferrate(II). One more complex containing the hexacyanoferrate(II), [{Mn-III(salpn)(CH3OH)(0.67)(H2O)(0.33)}(6)Fe-II(CN)(6)]{ClO4}(2)center dot 8H(2)O (4), is obtained in the reaction of [Fe(II)(CN)(6)](4-) with the cationic complex [Mn-2(salpn)(2)(H2O)(2)](ClO4)(2). The iron(II) centers in the complexes 2 and 4 are linked via cyano-bridges with the four and six [Mn-III(salpn)](+) fragments, respectively. The structure of 3 consists of the cyano-bridged [(Mn6FeII)-Fe-III] repeating units linked by double phenolate bridges into a one-dimensional polymeric chain. The magnetic properties of 3 indicate a ferromagnetic coupling between Mn-III centers in the double phenolate-bridged [Mn-III(salpn)](2) dinuclear subunits. Quantum calculations within the Heisenberg-Van Vleck model are performed giving the exchange constant J = 0.64 cm(-1) and the zero-field splitting parameter D = -3.5 +/- 0.5 cm(-1). The ac-susceptibility obeys the Arrhenius law with the activation energy E-a = 11.89 cm(-1).