Syntheses, structures, and magnetic properties of tetranuclear Ni4II and Ni2IIMn2III complexes with ONO tridentate ligands

Tetranuclear Ni4II and Ni2IIMn2III complexes of N-(2-hydroxymethylphenyl)salicylideneimine (H2L1), [Ni4Cl2(L1)2(HL1)2] (1), [Mn2Ni2Cl2(L1)4(H2O)2] (2), and Ni(II)4 complex of N-(2-hydroxymethylphenyl)salicylamine (H2L2), [Ni4(L2)4(CH3OH)2] (3) have been characterized by X-ray crystal structure analyses and magnetic measurements. The structure analyses revealed that complexes 1 and 2 have a defective double-cubane metal core connected by μ3-alkoxo bridges. Complex 1 contains two types of tridentate ligands coordinating as dianionic (L12−) and monoanionic (HL1−). The double-cubane core of 1 is significantly distorted due to an effect of chloride anions as bridging atoms. Complex 2 consists of two μ-phenoxo NiII–MnIII heteronuclear units making a dimer-of-dimers structure. Complex 3 contains dianionic (L2)2− ligands and forms Ni4II cubane core. Magnetic measurements of complex 2 indicate that a weak ferromagnetic interactions (JNiMn = 1.5 cm−1, JNiNi = 20 cm−1) are dominant in this hetero-metal core.

Tetranuclear Ni4II and Ni2IIMn2III complexes with a unique defective double-cubane core connected by μ3-alkoxo bridges of N-(2-hydroxymethylphenyl)salicylideneimine have been characterized by X-ray crystal structure analyses and magnetic measurements. Magnetic susceptibility measurements revealed an S = 6 ground state of Ni2IIMn2III double-cubane.Figure optionsDownload as PowerPoint slide