Li Zhong-Yi, Xu Ya-Lan, Zhang Xiang-Fei, Zhai Bin, Zhang Fu-Li, Zhang Jian-Jun, Zhang Chi, Li Su-Zhi, Cao Guang-Xiu
Engineering Research Center of Photoelectric Functional Material, Henan Key Laboratory of Biomolecular Recognition and Sensing, College of Chemistry and Chemical Engineering, Shangqiu Normal University, Shangqiu 476000, P. R. China.
Chemistry College, Dalian University of Technology, Dalian 116024, P. R. China.
Dalton Trans. 2017 Dec 21;46(47):16485-16492. doi: 10.1039/c7dt03562d. Epub 2017 Nov 17.
Four isostructural lanthanide coordination polymers with a phenylacetate (PAA) ligand, [Ln(PAA)(HO)] (Ln = Eu (1); Gd (2); Tb (3); Dy (4)), were synthesized under hydrothermal conditions. Complexes 1-4 display a one-dimensional (1D) wave chain structure bridged by the carboxylate of the PAA ligand, which was generated via the in situ decarboxylation of phenylmalonic acid. Magnetic studies suggest the presence of ferromagnetic LnLn coupling in the 1D chain of 1-4. Meanwhile, 2 has a significant cryogenic magnetocaloric effect with the maximum -ΔS of 26.73 at 3 K and 7 T, and 3 and 4 show interesting spin-glass behavior, which is rarely reported for Ln-containing complexes. Additionally, the solid-state photophysical properties of 1 and 3 display strong characteristic Eu and Tb photoluminescence emission in the visible region, indicating that Eu- and Tb-based luminescence are sensitized by the effective energy transfer from the ligand to the metal centers.
在水热条件下合成了四种具有苯乙酸（PAA）配体的同构镧系配位聚合物，即[Ln(PAA)(HO)]（Ln = Eu (1)；Gd (2)；Tb (3)；Dy (4)）。配合物1-4呈现出一种一维（1D）波链结构，由PAA配体的羧酸盐桥连而成，该结构是通过苯丙二酸的原位脱羧反应生成的。磁性研究表明，在1-4的一维链中存在铁磁Ln-Ln耦合。同时，2具有显著的低温磁热效应，在3 K和7 T时最大-ΔS为26.73，3和4表现出有趣的自旋玻璃行为，这在含Ln配合物中很少报道。此外，1和3的固态光物理性质在可见光区域显示出强烈的Eu和Tb特征光致发光发射，表明基于Eu和Tb的发光是通过从配体到金属中心的有效能量转移而被敏化的。
