Substituent Positioning Effects on the Magnetic Properties of Sandwich-Type Erbium(III) Complexes with Bis(trimethylsilyl)-Substituted Cyclooctatetraenyl Ligands

Chen, Qi-Wei1,2; Ding, You-Song2,3; Zhu, Xiao-Fei1; Wang, Bing-Wu4; Zheng, Zhiping2,3

2023-12-22

10.1021/acs.inorgchem.3c03369

INORGANIC CHEMISTRY   影响因子和分区

0020-1669

1520-510X

Lanthanide complexes with judiciously designed ligands have been extensively studied for their potential applications as single-molecule magnets. With the influence of ligands on their magnetic properties generally established, recent research has unearthed certain effects inherent to site differentiation due to the different types and varying numbers of substituents on the same ligand platform. Using two new sandwich-type Er(III) complexes with cyclooctatetraenyl (COT) ligands featuring two differently positioned trimethylsilyl (TMS) substituents, namely, [Li(DME)Er(COT1,5-TMS2)(2)](n) (Er1) and [Na(DME)(3)][Er(COT1,3-TMS2)(2)] (Er2) [COT1,3-TMS2 and COT1,5-TMS2 donate 1,3- and 1,5-bis(trimethylsilyl)-substituted cyclooctatetraenyl ligands, respectively; DME = 1,2-dimethoxyethane], and with reference to previously reported [Li(DME)(3)][Er(COT1,4-TMS2)(2)] (A) and [K(DME)(2)][Er(COT1,4-TMS2)(2)] (B), any possible substituent position effects have been explored for the first time. The rearrangement of the TMS substituents from the starting COT1,4-TMS2 to COT1,3-TMS2 and COT1,5-TMS2, by way of formal migration of the TMS group, was thermally induced in the case of Er1, while for the formation of Er2, the use of Na+ in the placement of its Li+ and K+ congeners is essential. Both Er1 and Er2 display single-molecule magnetic behaviors with energy barriers of 170(3) and 172(6) K, respectively. Magnetic hysteresis loops, butterfly-shaped for Er1 and wide open for Er2, were observed up to 12 K for Er1 and 13 K for Er2. Studies of magnetic dynamics reveal the different pathways for relaxation of magnetization below 10 K, mainly by the Raman process for Er1 and by quantum tunneling of magnetization for Er2, leading to the order of magnitude difference in magnetic relaxation times and sharply different magnetic hysteresis loops.

SCI ; EI

英语

通讯

National Natural Science Foundation of China["92261203","22101116","21971106"] ; National Natural Science Foundation of China[YDZJ202301ZYTS478] ; Science Research Foundation of Jilin Province["JCYJ20220530115001002","JCYJ20220818100417037"] ; Shenzhen Fundamental Research Program[20200925161141006] ; Stable Support Plan Program of Shenzhen Natural Science Fund[2022KSYS006]

Chemistry

Chemistry, Inorganic & Nuclear

WOS:001158887100001

AMER CHEMICAL SOC

CHEMISTRY

Web of Science

1.Changchun Univ Technol, Sch Chem & Life Sci, Changchun 130012, Peoples R China
2.Southern Univ Sci & Technol, Dept Chem, Shenzhen 518055, Guangdong, Peoples R China
3.Southern Univ Sci & Technol, Key Univ Lab Rare Earth Chem Guangdong, Shenzhen 518055, Guangdong, Peoples R China
4.Peking Univ, Coll Chem & Mol Engn, Beijing Natl Lab Mol Sci, Beijing 100871, Peoples R China

Chen, Qi-Wei,Ding, You-Song,Zhu, Xiao-Fei,et al. Substituent Positioning Effects on the Magnetic Properties of Sandwich-Type Erbium(III) Complexes with Bis(trimethylsilyl)-Substituted Cyclooctatetraenyl Ligands[J]. INORGANIC CHEMISTRY,2023,63(21).

Chen, Qi-Wei,Ding, You-Song,Zhu, Xiao-Fei,Wang, Bing-Wu,&Zheng, Zhiping.(2023).Substituent Positioning Effects on the Magnetic Properties of Sandwich-Type Erbium(III) Complexes with Bis(trimethylsilyl)-Substituted Cyclooctatetraenyl Ligands.INORGANIC CHEMISTRY,63(21).

Chen, Qi-Wei,et al."Substituent Positioning Effects on the Magnetic Properties of Sandwich-Type Erbium(III) Complexes with Bis(trimethylsilyl)-Substituted Cyclooctatetraenyl Ligands".INORGANIC CHEMISTRY 63.21(2023).