Abstract

A novel hetero-hexanuclear [Cu^II₄Gd^III₂] complex with a symmetrical bis(salamo)-like tetraoxime ligand (H₄L), [{Cu₂(L)(MeOH)Gd(NO₃)₂(μ₂-NO₃)}₂]·2CH₃OH was obtained after careful design and synthesis. The structure of the [Cu^II₄Gd^III₂] complex was adequately characterized by elemental analysis, FTIR, and UV–vis spectroscopy. The [Cu^II₄Gd^III₂] complex crystallized in the monoclinic system, space group C2/c embraces four Cu^II ions with two coordination geometries: tetragonal pyramid and octahedron, two Gd^III ions with nine coordinated tricapped trigonal prism geometry, two completely deprotonated octadentate (L)^4– units, two coordinated methanol molecules, two bidentate bridging nitrate groups (μ₂-NO₃^–), four bidentate chelating nitrate groups and two crystallized methanol molecules. The [Cu^II₄Gd^III₂] complex ultimately constructs infinite 2D and 3D supramolecular structures via the intermolecular hydrogen bond interactions. Meanwhile, the fluorescence properties of the ligand (H₄L) and its [Cu^II₄Gd^III₂] complex were studied. The electronic structure and stability of the [Cu^II₄Gd^III₂] complex were proved by density functional theory calculation.

摘要

一种新型的杂六核 [Cu ^II ₄ Gd ^III ₂ ] 配合物，具有对称的双 (salamo) 样四肟配体 (H ₄ L)，[{Cu ₂ (L)(MeOH)Gd(NO ₃ ) ₂ ( μ ₂ -NO ₃ )} ₂ ]·2CH ₃ OH 经过精心设计和合成。[Cu ^II ₄ Gd ^III ₂ ]配合物的结构通过元素分析、FTIR和UV-vis光谱进行了充分表征。[Cu ^II ₄ Gd ^III ₂] 在单斜晶系中结晶的配合物，空间群C2/c包含四个 Cu ^II离子，具有两种配位几何形状：四角锥和八面体，两个 Gd ^III离子具有九个配位三棱柱几何形状，两个完全去质子化的八齿 (L) ^4–单位，两个配位的甲醇分子，两个双齿桥接硝酸盐基团（μ ₂ -NO ₃ ^–），四个双齿螯合硝酸盐基团和两个结晶的甲醇分子。[Cu ^II ₄ Gd ^III ₂] 复合物最终通过分子间氢键相互作用构建无限的 2D 和 3D 超分子结构。同时，研究了配体(H ₄ L)及其[Cu ^II ₄ Gd ^III ₂ ]配合物的荧光性质。通过密度泛函理论计算证明了[Cu ^II ₄ Gd ^III ₂ ]配合物的电子结构和稳定性。