经甲酸盐改性的硫酸钆以获得优化的磁热效应。
Gadolinium sulfate modified by formate to obtain optimized magneto-caloric effect.
作者信息
Xu Long-Yang, Zhao Jiong-Peng, Liu Ting, Liu Fu-Chen
机构信息
†School of Chemistry and Chemical Engineering, Tianjin University of Technology, No. 391 Binshui Xilu Road, Tianjin 300384, P. R. China.
§School of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124, P. R. China.
出版信息
Inorg Chem. 2015 Jun 1;54(11):5249-56. doi: 10.1021/acs.inorgchem.5b00214. Epub 2015 May 15.
Three new Gd(III) based coordination polymers [Gd2(C2H6SO)(SO4)3(H2O)2]n (1), {[Gd4(HCOO)2(SO4)5(H2O)6]·H2O}n (2), and [Gd(HCOO)(SO4)(H2O)]n (3) were obtained by modifying gadolinium sulfate. With the gradual increase of the volume ratio of HCOOH and DMSO in synthesis, the formate anions begin to coordinate with metal centers; this results in the coordination numbers of sulfate anion increasing and the contents of water and DMSO molecules decreasing in target complexes. Accordingly, spin densities both per mass and per volume were enhanced step by step, which are beneficial for the magneto-caloric effect (MCE). Magnetic studies reveal that with the more formate anions present, the larger the negative value of magnetic entropy change (-ΔSm) is. Complex 3 exhibits the largest -ΔSm = 49.91 J kg(-1) K(-1) (189.51 mJ cm(-3) K(-1)) for T = 2 K and ΔH = 7 T among three new complexes.
通过修饰硫酸钆得到了三种新型的基于Gd(III)的配位聚合物[Gd2(C2H6SO)(SO4)3(H2O)2]n (1)、{[Gd4(HCOO)2(SO4)5(H2O)6]·H2O}n (2)和[Gd(HCOO)(SO4)(H2O)]n (3)。随着合成过程中HCOOH和DMSO体积比的逐渐增加，甲酸根阴离子开始与金属中心配位；这导致目标配合物中硫酸根阴离子的配位数增加，水和DMSO分子的含量减少。相应地，每质量和每体积的自旋密度逐步增强，这有利于磁热效应（MCE）。磁性研究表明，存在的甲酸根阴离子越多，磁熵变（-ΔSm）的负值越大。在三种新型配合物中，配合物3在T = 2 K和ΔH = 7 T时表现出最大的-ΔSm = 49.91 J kg(-1) K(-1)（189.51 mJ cm(-3) K(-1)）。
Zotero 插件