Sandwich-Type Single-Molecule Magnets Complexes of Er(III) with Ansa-Cyclooctatetraenyl Ligands

Ding, You-Song1,2; Chen, Qi-Wei1,3; Huang, Jia-Qi1,2; Zhu, Xiao-Fei3; Zheng, Zhiping1,2

2024-08-01

10.1002/cjoc.202400600

CHINESE JOURNAL OF CHEMISTRY   影响因子和分区

1001-604X

1614-7065

Many sandwich-type lanthanide complexes show extremely high energy barriers (U-eff) for the reversal of magnetization and high blocking temperatures, being the star molecules in the research area of single-molecule magnets. Herein, the preparation, structural determination, and magnetic property studies of two ansa-bridged Er-COT (COT = cyclooctatetraenyl dianion) complexes [KDME2][Er((eta(8)-COT-Si-Me2)(2)O)] (1) and [KDME2][Er((eta(8)-COT-Si-iPr2)(2)O)]K[Er((eta(8)-COT-Si-iPr2)(2)O)] (2) were reported. The Er(III) ions in both complexes are sandwiched by two COT rings which are ansa-bridged by a [Si-O-Si] group. Magnetic studies reveal both complexes display slow magnetic relaxations with comparable energy barriers (228(5) K for 1, and 196(4) K for 2) and blocking temperatures (10.5 K for both complexes). The difference in the relaxation times (tau) for the two complexes was studied in details: different molecular vibrations induced by the substituents are the main reason for tau for 1 being about 10 times longer than for 2 at the same temperature above 10 K, while the quantum tunnelling of magnetization relaxation time (tau(QTM)) for 2 is about 10 times longer than for 1 below 8 K, probably owing to the different dipolar interactions. Further rearrangement of molecular network with such ansa-bridged SMMs is promising to design molecular magnetic materials with enhanced properties or new properties.

Single-molecule magnet Cyclooctatetraenyl dianion Sandwich-type complex Ansa-bridge ligand Dipolar interaction Blocking temperature Quantum tunneling of magnetization Magnetic relaxation time

SCI

英语

第一 ; 通讯

National Natural Science Foundation of China["92261203","22101116","21971106"] ; Key Laboratory of Rare Earth Chemistry of Guangdong Higher Education Institutes[2022KSYS006] ; Stable Support Plan Program of Shenzhen Natural Science Fund[20200925161141006] ; Shenzhen Fundamental Research Program["JCYJ20220530115001002","JCYJ20220818100417037"]

Chemistry

Chemistry, Multidisciplinary

WOS:001286783700001

WILEY-V C H VERLAG GMBH

CHEMISTRY

Web of Science

1.Southern Univ Sci & Technol, Dept Chem, Shenzhen 518055, Guangdong, Peoples R China
2.Southern Univ Sci & Technol, Key Univ Lab Rare Earth Chem Guangdong, Shenzhen 518055, Guangdong, Peoples R China
3.Changchun Univ Technol, Sch Chem & Life Sci, Changchun 130012, Jilin, Peoples R China

Ding, You-Song,Chen, Qi-Wei,Huang, Jia-Qi,et al. Sandwich-Type Single-Molecule Magnets Complexes of Er(III) with Ansa-Cyclooctatetraenyl Ligands[J]. CHINESE JOURNAL OF CHEMISTRY,2024.

Ding, You-Song,Chen, Qi-Wei,Huang, Jia-Qi,Zhu, Xiao-Fei,&Zheng, Zhiping.(2024).Sandwich-Type Single-Molecule Magnets Complexes of Er(III) with Ansa-Cyclooctatetraenyl Ligands.CHINESE JOURNAL OF CHEMISTRY.

Ding, You-Song,et al."Sandwich-Type Single-Molecule Magnets Complexes of Er(III) with Ansa-Cyclooctatetraenyl Ligands".CHINESE JOURNAL OF CHEMISTRY (2024).