Synthesis, structure and magnetism of new polynuclear transition metal aggregates assembled with Schiff-base ligand and anionic N-donor ligands

Three new polynuclear aggregates [Co6(sae)4(N3)6(MeO)2(MeOH)2]·0.5H2O (1), [Mn4O(sae)4(C(CN)3)(MeOH)3](NO3)·MeOH (2) and [NaFe6(sae)6(MeO)6] (N(CN)2)·H2O (3) have been synthesized with mixed ligands of Schiff-base (salicylidene-2-ethanolamine, H2sae) and various anionic N-donor ligands (N3−, N(CN)2− or C(CN)3−) and transition metal salts in methanol solution. Crystallographic data for 1: trigonal, R3¯, a = 26.113(4) Å, b = 26.113(4) Å, c = 20.689(4) Å, γ = 120°, V = 12,218(3) Å3, Z = 9, R1(wR2) = 0.0753(0.2176); for 2: orthorhombic, Pna21, a = 20.746(4) Å, b = 13.357(3) Å, c = 17.992(4) Å, V = 4985.6(2) Å3, Z = 4, R1(wR2) = 0.0357(0.0969); for 3: monoclinic, C2/c, a = 30.311(6) Å, b = 12.452(3) Å, c = 20.789(4) Å, β = 94.75(3)°, V = 7820(3) Å3, Z = 4, R1(wR2) = 0.0773(0.2299). Compound 1 exhibits a new rod-like [CoIII4CoII2] structural feature. Compound 2 contains an unusual tetranuclear [MnIII4] cationic core. Compound 3 possesses a well-known circle-like [FeIII6] unit encapsulated a central sodium cation. Magnetic properties of these compounds have been studied revealing the presence of (i) intra-molecular antiferromagnetic interactions in 2 and 3 that induce an overall ST = 0 ground state and (ii) CoII–CoII ferromagnetic interactions in complex 1.