期刊
CRYSTENGCOMM
卷 19, 期 16, 页码 2229-2242出版社
ROYAL SOC CHEMISTRY
DOI: 10.1039/c7ce00234c
关键词
-
资金
- Red Guipuzcoana de Ciencia, Tecnologia e Innovacion [OF215/2016]
- University of the Basque Country [GIU14/01, EHUA16/32]
- Junta de Andalucia [FQM-1484]
- Ministerio de Economia, Industria y Competitividad of Spain [CTQ2014-56312-P, MAT2016-75883-C2-1-P]
- University of the Basque Country (UPV/EHU)
- ERDF
- ESF
We report herein the synthesis and structural and chemical characterization of six new compounds consisting of 6-aminonicotinate (6ani) ligands and first-row transition metal ions, namely, [Mn2(mu-6ani)(2)(H2O)(8)](6ani)(2) (1), [Co(6ani)(bipy)(2)(H2O)(3)](6ani)center dot 5H(2)O (2), [M(mu-6ani)(6ani)(H2O)(3)]center dot 2H(2)O [M-II = Co (3), Ni (4)], and [M(mu-6ani)(2)]center dot H2O [M-II = Co (5), Cu (6)] (where bipy = 4,4'-bipyridine). Compounds 1 and 2 consist of isolated dimeric and monomeric entities held together by supramolecular interactions governed by 6ani free anions. The rigid and low symmetry of 6ani ligands, in addition to their coordination as terminal and bridging ligands to octahedral metal geometries, gives rise to chiral 1D chains of compounds 3 and 4. 2D sql layers are formed (5 and 6) when 6ani ligands act as ligands bridging the metal ions, which precludes the presence of water molecules in the framework. Despite the wide structural diversity observed, all architectures share the occurrence of magnetically isolated 3d metal ions, given the poor exchange achieved through 6ani bridges, as confirmed by dc susceptibility measurements and DFT calculations. Dynamic ac susceptibility measurements reveal best-in-class field-induced slow magnetic relaxation behaviour in Co-based compounds with easy-plane magnetic anisotropy. The effective energy barriers (U-eff) of 39.6 K and 18.7 K for 3 and 5, respectively, estimated using the Arrhenius law are remarkably high among Co-II-SIM coordination polymers reported so far.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据