Tetranuclear Homo‐ and Heterometallic Manganese(III) and Nickel(II) Complexes: Synthesis, Structure, and Magnetic Studies

Abstract

AbstractThree new polynuclear cluster complexes were synthesized and characterized using single‐crystal X‐ray measurements, infrared spectroscopy, and elemental analyses. A Schiff‐base, 2‐{[(1‐hydroxybutan‐2‐yl)imino]methyl}phenol (himpH2), synthesized in situ from the reaction of salicylaldehyde and (±)‐2‐aminobutanol, was used as ligand. Reactions of the ligand with different MnII and NiII salts led to two homometallic complexes and a heterometallic complex with [MnIII4] (1), [NiII4] (2), and [MnIII2NiII2] (3) cores exhibiting square, cubane‐type, or butterfly arrangement, respectively. Analysis of the temperature dependence of the magnetic susceptibility of compounds 1–3, using appropriate spin Hamiltonians, indicated that the [MnIII4] and [NiII4] compounds show dominant ferromagnetic coupling of the spin carriers, whereas the [Mn2Ni2] compound has antiferromagnetic MnIII–NiII and ferromagnetic NiII–NiII interactions, with a spin ground state St = 2. Analyses of the magnetization data in 0–5 T fields at 2 K indicate the presence of positive zero‐field splitting (ZFS) values, which is consistent with the absence of slow magnetic relaxation.