Heterometallic 3d–4d coordination polymers assembled from trans-[RuIII(L)(CN)2]− tectons and 3d cations

Abstract

Five new cyanido-bridged heterometallic coordination polymers have been obtained by reacting PPh₄[Ru^III(salpn)(CN)₂]·H₂O (1) and AsPh₄[Ru^III(valen)(CN)₂]·8.5H₂O (2) (H₂salpn and H₂valen being Schiff-base proligands resulting from the condensation reaction of salicylaldehyde with 1,3-propanediamine and, respectively, o-vanillin with 1,2-ethanediamine) with divalent transition metal perchlorate salts: ^∞₁[{Ru^III(salpn)(CN)₂}₃{M^II(DMF)₃}₂](ClO₄)·4DMF (M^II = Mn, 3; Co, 4) and ^∞₂[{Ru^III(valen)(CN)₂}₄{M^II(DMF)₃}₂{M^II(DMF)₄}](ClO₄)₂·4DMF (M^II = Mn, 5; Co, 6; Ni, 7), respectively. The dicyanido species, trans-[Ru(salpn)(CN)₂]⁻ and trans-[Ru(valen)(CN)₂]⁻, act as metalloligands with the 3d metal ions. Compounds 3 and 4 are isostructural one-dimensional (1D) coordination polymers with a ladder topology. Each M^II ion is hexacoordinated by three cyanido groups arising from three {Ru(salpn)(CN)₂} units and by the oxygen atoms from three DMF molecules, which are coordinated at meridional positions. Compounds 5–7 are also isostructural, their structures consisting of 2D networks with a herringbone topology. The magnetic susceptibility measurements of these 1D and 2D systems reveal the presence of dominating Ru^III–M^II antiferromagnetic (AF) interactions in compounds 3, 4, 5 and 6, while ferromagnetic Ru^III–Ni^II interactions are observed in 7. All these compounds stay in their paramagnetic state down to 1.8 K except compound 4 which possesses a 3D ordered AF ground state.