Desolvation-Driven 100-Fold Slow-down of Tunneling Relaxation Rate in Co(II)-Dy(III) Single-Molecule Magnets through a Single-Crystal-to-Single-Crystal Process

• Published in: Scientific reports Vol. 5; no. 1; p. 16621
• Main Authors: Liu, Jun-Liang, Wu, Jie-Yi, Huang, Guo-Zhang, Chen, Yan-Cong, Jia, Jian-Hua, Ungur, Liviu, Chibotaru, Liviu F., Chen, Xiao-Ming, Tong, Ming-Liang
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 17.11.2015; Nature Publishing Group
• Subjects: 119/118; 639/301/119/997; 639/638/263/911; Crystals; Humanities and Social Sciences; multidisciplinary; Science
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/srep16621

Single-molecule magnets (SMMs) are regarded as a class of promising materials for spintronic and ultrahigh-density storage devices. Tuning the magnetic dynamics of single-molecule magnets is a crucial challenge for chemists. Lanthanide ions are not only highly magnetically anisotropic but also highly sensitive to the changes in the coordination environments. We developed a feasible approach to understand parts of the magneto-structure correlations and propose to regulate the relaxation behaviors via rational design. A series of Co(II)-Dy(III)-Co(II) complexes were obtained using in situ synthesis; in this system of complexes, the relaxation dynamics can be greatly improved, accompanied with desolvation, via single-crystal to single-crystal transformation. The effective energy barrier can be increased from 293 cm −1 (422 K) to 416 cm −1 (600 K) and the tunneling relaxation time can be grown from 8.5 × 10 −4 s to 7.4 × 10 −2 s. These remarkable improvements are due to the change in the coordination environments of Dy(III) and Co(II). Ab initio calculations were performed to better understand the magnetic dynamics.