Regulating Spin Dynamics of Nitronyl Nitroxide Biradical Lanthanide Complexes through Introducing Different Transition Metals

被引：5

作者：

Jing, Pei ^{[1
]}

Xi, Lu ^{[1
]}

Lu, Jiao ^{[1
]}

Han, Jing ^{[1
]}

Huang, Xiaohui ^{[1
]}

Jin, Chaoyi ^{[1
]}

Xie, Junfang ^{[1
]}

Li, Licun ^{[1
]}

机构：

[1] Nankai Univ, Coll Chem, Key Lab Adv Energy Mat Chem, Dept Chem, Tianjin 300071, Peoples R China

来源：

CHEMISTRY-AN ASIAN JOURNAL | 2021年 / 16卷 / 07期

基金：

中国国家自然科学基金;

关键词：

nitronyl nitroxide biradical; transition metals; local symmetry; two-relaxation processes;

D O I：

10.1002/asia.202100062

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

Four biradical-Ln complexes with different transition metal ions, namely [LnM(hfac)(5)(NITPh-PyPzbis)] (M-II=Mn-II and Ln(III)=Gd 1, Dy 2; M-II=Ni-II and Ln(III)=Tb 3, Dy 4), were prepared by the reaction of Ln(hfac)(3) . 2H(2)O, Mn(hfac)(2) . 2H(2)O or Ni(hfac)(2) . 2H(2)O with NITPh-PyPzbis biradical (hfac=hexafluoroacetylacetonate, NITPh-PyPzbis=5-(3-(2-pyridinyl)-1H-pyrazol-1-yl)-1,3-bis(1'-oxyl-3'-oxido- 4',4',5',5'-tetramethyl-4,5-hydro-1H-imidazol-2-yl)benzene). In complexes 1-4, the NITPh-PyPzbis biradical chelates one Ln(III) ion by means of its aminoxyl moieties and the transition metal ion is introduced through the two N donors from the pyridyl pyrazolyl moiety. Magnetic investigations indicate that complex 4 displays visible maxima in frequency/temperature-dependent chi '' signals with two-step relaxation processes, but complex 2 exhibits no slow magnetization relaxation. The comparison of structure parameters of both Dy complexes indicates that the symmetries of coordination spheres of two Dy ions are D-2d for 2 and C-2v for 4, which thus probably results in different magnetic relaxation behaviors. This work provides new insight for improving properties of Ln-biradical based SMMs.

引用

页码：793 / 800

页数：8