Field-induced slow magnetic relaxation behaviours in binuclear cobalt(<scp>ii</scp>) metallocycles and exchange-coupled clusters
Dong Shao, Shruti Moorthy, Yue Zhou, Si-Tong Wu, Jing-Yan Zhu, Jiong Yang, Dongqing Wu, Zhengfang Tian, Saurabh Kumar Singh
Abstract
-imidazol-1-yl)methyl]benzene). Structural analyses revealed that complexes 1 and 2 are discrete binuclear molecules containing two neutral {Co(pdms)} species bridged by bpym and bimp ligands, respectively, forming an exchange-coupled CoII2 dimer and a rare CoII2 metallocycle. Magnetic studies found that 1 exhibits considerable antiferromagnetic interactions transferred by the bpym bridge while negligible magnetic interactions in 2 due to the long bimp ligands. Interestingly, both the complexes show significant magnetic anisotropy and thus exhibit slow magnetic relaxation under an external dc field originating from spin-lattice relaxation. Detailed theoretical calculations were further applied to understand the magnetic interactions and magnetic anisotropy in 1 and 2. The foregoing results highlight that coordination solids with programmed structures and magnetic properties can be designed and prepared through a judicious selection of molecular complex building blocks and organic linkers.