| Abstract
| - The isostructural, chiral molecular magnetic materials with the formula [MxM‘2-x(ca)2(1,4-dimb)]n [H2ca = D-(+)-camphoric acid, 1,4-dimb = 1,4-di-(1-imidazolyl-methyl)-benzene, M = NiII, M‘ = CoII, 0 ≤ x ≤ 2] consist ofca-bridged (4,4) layers with [M2(O2CR)4] as secondary building units that are pillared by the 1,4-dimb ligands intoa unique 3D framework. The high-spin octahedral symmetry and the proportions of the mixed-metal ions werecharacterized by UV−vis spectroscopy. The compounds exhibit the onset of antiferromagnetic ordering at 7.5∼23K, as well as weak ferromagnetism, spin-flop, and glassy behavior that result from the randomness of the mixed-metal pairs, magnetic anisotropy of the metallic cations, and antisymmetric exchange. The composites should beregarded as molecular alloys of the pure Ni(II) and Co(II) compounds. The magnetic behavior of the solid solutionsshows unambiguously that the organic bridges, bond angles, and bond distances greatly influence the effectiveinteractions and bring about cooperative magnetic behavior in the chiral 3D frameworks.
- Chiral 3D magnetic metal-organic frameworks (MOFs) featuring tetracarboxylate-bridged dimers with different mixed-metal compositions are reported, demonstrating that the mixed-metal solid solutions could show significant changes in magnetic properties and MOFs of appropriate magnetic multinuclear secondary building units are potential molecular magnetic alloy materials through tuning the mixed-metal compositions.
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