Department of Chemistry, University of Ottawa, 10 Marie Curie Private, Ottawa, ON, Canada K1N 6N5.
Dalton Trans. 2013 Jun 7;42(21):7795-802. doi: 10.1039/c3dt33000a.
Two novel Co-based metal-organic frameworks (MOFs) were synthesised and characterised using an asymmetrically binding ligand, 4-(4'-carboxyphenyl)-1,2,4 triazole (Hcpt). The isolated [Co3(II)(μ3-O)(OH)(cpt)3(H2O)2]n·xH2O·yDMF, Co-MOF1, exhibits a rhombohedral crystal structure (space group, P63/mc), with a trinuclear cobalt core that resembles the MIL88 series. This MOF shows paramagnetic behaviour down to 2 K with no saturation of magnetisation up to 7 T. This is presumably due to a geometrically frustrated triangular arrangement of Co spins. The two-dimensional complex, [Co(II)(cpt)(N3)]n, Co-MOF2, crystallises in a monoclinic crystal system (space group, C2/m). The magnetic measurements reveal metamagnetic behaviour for this complex with a critical field in the range of 700-1000 Oe.
两种新型的基于钴的金属有机骨架（MOFs）是使用不对称结合配体 4-(4'-羧基苯基）-1,2,4 三唑（Hcpt）合成并进行了表征。分离得到的[Co3(II)(μ3-O)(OH)(cpt)3(H2O)2]n·xH2O·yDMF，即 Co-MOF1，具有菱面体晶体结构（空间群，P63/mc），包含一个类似于 MIL88 系列的三核钴核。该 MOF 在 2 K 以下表现出顺磁行为，在 7 T 以下没有磁化饱和。这可能是由于 Co 自旋的几何上受阻的三角形排列。二维配合物[Co(II)(cpt)(N3)]n，即 Co-MOF2，在单斜晶系（空间群，C2/m）中结晶。磁性测量表明该配合物具有变磁行为，其临界场在 700-1000 Oe 范围内。
