Design and Self-Assembly of Ferrocene-Functional Heterometal–Oxo Clusters with the M(III)4O4Cubane Core

In this work, we synthesized two Cu-based heterometal–oxo clusters 1and 2based on M(III)4O4(M = Fe/In) cubane centers and obtained the corresponding dimers 3and 4by connecting Cu atoms on the cluster cores with the auxiliary ligand 4,4′- bipyridine. They were characterized by single-crystal X-ray diffraction (SCXRD), powder X-ray diffraction (PXRD), and other tests. We conducted magnetic property study on compounds 1–4. The variable-temperature magnetic susceptibility test shows that compounds 1and 3exhibit significant ferromagnetic interactions at low temperatures, while compounds 2and 4exhibit overall antiferromagnetic interactions. When the metal at the cubane changes from magnetic Fe to nonmagnetic In, the magnetic interactions in the compound are weakened to a certain extent. Through dimerization, the extreme values of the variable-temperature magnetic susceptibility appear (1to 3)/disappear (2to 4) in the low-temperature section. We investigated the magnetic structure correlation of compounds 1–4through bond lengths, bond angles, and distances between magnetic atoms. The results showed that compounds 1–4exhibited significant magnetic coupling diversity.