Slow magnetic relaxation behaviors and diamagnetic dilution studies of a carboxyl bridged dinuclear dysprosium(Ⅲ)complex

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外文摘要：By using a rigid bulky carboxylic ligand α-cyanocinnamic acid(CCA),a dinuclear dysprosium(Ⅲ)com-plex[Dy2(CCA)6(MeOH)4](1)was synthesized.Single crystal X-ray crystallography reveals that the two eight-coordinate dysprosium ions are bridged by four deprotonated carboxyl groups,forming a centrosymmetric paddle-wheel-like structure.Dynamic magnetic property measurements indicate that complex 1 displays field-induced slow magnetic relaxation.The temperature-dependent relaxation times can be fitted using Orbach and Raman processes with parameters of n=2.8(2),C=27(8)s-1/Kn,τ0=5(2)x 10-10 s and Ueff=40(3)cm-1.Magnetic studies on the diamagnetic YⅢ-diluted analogue[Dy0.206Y1.794(CCA)6(MeOH)4](2)reveal its slow magnetic relaxation behavior without external dc field and the antiferromagnetic coupling between the DyⅢ ions in 1.Fits on the obtained relaxation times of 2 lead to the parameters of n=4.5(3),C=0.7(2)s-1/Kn,τ0=2.8(2)× 10-9 s and Ueff=38(2)cm-1.The results suggest that slow magnetic relaxation originates from the single-ion relaxation of DyⅢ ions.Moreover,the diamagnetic dilution can suppress other fast relaxation pathways at low temperature,on account of the elimination of magnetic coupling and dipolar interaction.Ab initio calculations were then performed on the single DyⅢ ion species {YDy} and indicate that the first excited Kramers doublets(KDs)lie at ca.76 cm-1,which is slightly higher than the experimental Ueff value.The intramolecular magnetic interactions were also calculated and indicate a weak ferromagnetic dipole-diploe magnetic interaction and an antiferromagnetic exchange coupling.

外文关键词：

Single-molecule magnetsDilanthanide complexesDiamagnetic dilutionRare earths

作者：

Wenting Liu、Yibo Qiu、Weiqin Xu、Manli Cao、Xin Deng、Weiquan Lin

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作者单位：

School of Chemistry and Materials Science,Guangdong University of Education,Guangzhou,510303,China

School of Chemistry and Chemical Engineering/Institute of Clean Energy and Materials,Guangzhou University,Guangzhou,510006,China

基金：

National Natural Science Foundation of ChinaNational Natural Science Foundation of ChinaNatural Science Foundation of Guangdong ProvinceNatural Science Foundation of Guangdong ProvinceScience and Technology Research Project of GuangzhouScience and Technology Research Project of GuangzhouProject for Key Areas of Ordinary Colleges and Universities of Guangdong Provincethe"Climbing Program"Special Funds of Guangdong Province

项目编号：

21805048220050692022A15150111452023A15150106022021020800232022010201662022ZDZX4035pdjh 2023b0389

出版年：

2024

DOI：

10.1016/j.jre.2023.09.021

稀土学报(英文版)

中国稀土学会

稀土学报(英文版)

CSTPCDEI

影响因子：1.3

ISSN：1002-0721

年,卷(期)：2024.42(11)