The synthesis, structures and magnetic properties of polynuclear RuIII–3d (3d = MnII/III, NiII, CuII) compounds based on [RuIII(Q)2(CN)2]−

Abstract

The synthesis, crystal structures and magnetic properties of six cyano-bridged heterobimetallic compounds prepared from a paramagnetic Ru^III building block, trans-(PPh₄)[Ru^III(Q)₂(CN)₂] (1) (Q = the anion of 8-hydroxyquinoline), are described. 1 reacts with hydrated MnCl₂ in MeOH or DMF to produce a trinuclear compound {[Ru^III(Q)₂(CN)₂]₂[Mn^II(MeOH)₄]}·8MeOH (2), or a 1-D zigzag chain {[Mn^II(DMF)₂(Cl)](μ-CN)₂[Ru^III(Q)₂]}_n(3). The Mn^II has a distorted octahedral environment in 2 and a trigonal-bipyramidal environment in 3. 1 reacts with [Mn^III(L¹)(Cl)(H₂O)] in MeOH to produce the 1-D {[Ru^III(Q)₂](μ-CN)₂[Mn^III(L¹)]}_n (4) that consists of alternating Mn^III and Ru^III units. 1 also reacts with [Cu^II(cyclam)Br₂] and [Ni^II(cyclam)Cl₂] in MeOH to produce the trinuclear complexes [Ru^III(Q)₂(CN₂)]₂[M^II(cyclam)] (M = Cu^II (5) and Ni^II (6)). On the other hand, the reaction of 1 with [Ni^II(cyclen)Cl₂] produces a 1-D zigzag chain {([Ru^III(Q)₂(CN₂)][Ni^II(cyclen)])[Ru^III(Q)₂(CN₂)]}_n (7). Compounds 2–4 exhibit antiferromagnetic coupling between Ru^III and Mn^III/II centres. Antiferromagnetic coupling also occurs between Ru^III and Cu^II centres in 5. On the other hand, compounds 6 and 7 exhibit ferromagnetic coupling between Ru^III and Ni^II through cyanide bridges.