一种新颖的稀土-2-羟基烟酸的配合物的结构和光谱性质研究

通过水热反应合成了一种新颖的稀土2-羟基烟酸的配合物{LaL(HL)(H2O)3]1/3(SO4)2/3(H3O)2H2O}(H2L=2-hydroxynicotinic acid)。X-ray单晶衍射分析可知,2-羟基烟酸通过羧基O和羟基O原子桥连La离子,形成二维层状结构,层与层之间通过弱作用力拓展为三维结构。二维相关光谱分析表明N—H面外弯曲振动和C—H面外弯曲振动对磁微扰比较敏感,这可能是吡啶环上π电子云在磁微扰下变形引起C—H和N—H面外弯曲振动的响应,SO24-的ν4振动和羧基不对称伸缩振动对磁微扰也比较敏感;热微扰下N—H伸缩振动比较敏感。此外还对化合物进行了紫外和热重分析。

Structural and spectral study of a novel lanthanide 2-hydroxynicotinic acid coordination polymer

A novel lanthanide 2-hydroxynicotinic acid coordination polymer 1 {LaL(HL) (H2O)3]1/3 (SO4)2/3 (H3O)2 H2O} (H2 L = 2-hydroxynicotinic acid) has been synthesized under hydrothermal condition and characterized by crystal X-ray diffraction, IR, UV, TGA, two-dimensional infrared (2D IR) correlation spectroscopy with magnetic and thermal perturbation. In 1, La ions are connected by 2-hydroxynicotinic acid through both carboxylate oxygen atoms and oxygen atoms from hydroxyl group in pyridine to generate a 2D layer in the ab plane, these layers are further connected by weak interactions to form a 3D framework along c axis. The response of out-of-plane bending vibrations of N-H and C-H are remarkable in the 2D IR correlation spectra under magnetic perturbation, this may attributes to the inducement of pi-electron cloud deformation under magnetic perturbation, v4 vibrations from SO4(2-) was also sensitive to magnetic perturbation. In addition, stretching vibrations from N-H are sensitive to thermal perturbation.