基于4H-1,2,4-三氮唑-4-乙酸配体的两个新的过渡金属配位聚合物的合成、结构与性质(英文)

Synthesis and characterization of two new 2D coordination polymers of Co(Ⅱ),Ni(Ⅱ)based on 4H-1,2,4-Triazole-4-acetic acid

用水热方法合成了两个新的配位聚合物[Co(trza)](1)和[Ni(trza)(H2O)2](2)(Htrza=4H-1,2,4-三氮唑-4-乙酸)。单晶X-射线衍射结构分析表明:化合物1和2具有二维(2D)层状结构。在1中,Co(II)离子采用六配位方式,分别与来自两个不同配体(trza)上的两个氮原子和四个羧基氧原子配位,形成八面体配位聚合物,每个羧基以二齿桥联方式连接两个Co原子,形成1D链,这些一维链进一步与唑环上的N原子形成2D层状结构。在2中,中心Ni(II)离子采用同样的配位模式形成八面体配位聚合物,与1不同的是:来自两个配体阴离子(trza)上的两个羧基氧原子分别被两个配位水分子所取代,且配体上的羧基氧原子采用的是单齿配位模式。化合物1的变温磁化率测定表明了金属间弱的反铁磁相互作用。此外,两个配位聚合物的IR光谱、热稳定性以及化合物1的磁性质也被测定。

Two novel coordination polymer[ Co （ trza ） ]n （ 1 ） and [ Ni （trza） （ H2O ）2 ], （2） （ Htrza = 4H-1,2,4-triazole-4-acetic acid） have been hydrothermally synthesized and characterized by single-crystal X-ray diffraction analysis. The results show that 1 and 2 are two-dimensional （ 2D ） layered coordination polymers. In 1, each Co center is sixcoordinated by four carboxylate O atoms from four different trza anionic ligands and two N atoms from another two trza anionic ligands. The carboxylate groups adopts syn-skew coordination mode assembling Co（Ⅱ） into 1 D chains, which are linked to 2D layer through the coordination of N atoms from triazole rings. In 2, each Ni （Ⅱ）center is also sixcoordinated ,but two water molecules take the place of two carboxylate O atoms and the carboxylate group in 2 adopts monodentate coordination mode. Temperature-dependent magnetic measurements indicate the existence of antiferromagnetic interactions in 1. In addition ,the two compounds are further characterized by elemental analysis, IR and thermogravimetric analysis.