具有螺旋结构的金属镍有机-无机配位聚合物的合成及表征

在水热体系中合成了3个中心金属为镍离子, 以六配位扭曲八面体构型形成的具有螺旋结构的配位聚合物{Ni₂L₂(bib)₂·2H₂O]·5H₂O}_n(1), Ni₂L₂(bpy)]_n(2)和{Ni₂L₂(bibpip)₂·2H₂O]·6H₂O}_n(3)H₂L=4,4'-三苯胺二甲酸; bib=1,3-二(咪唑基)苯; bpy=4,4-联吡啶; bibpip=1,4-二(4-咪唑苄基)哌嗪]. 通过单晶及粉末X射线衍射、 红外光谱、 元素分析和热重分析对这3种化合物进行了表征. 结果表明, 化合物1属于单斜晶系, C2/c空间群, 其骨架为具有{4²·6⁵·8}拓扑结构的二维层结构; 化合物2属于斜方晶系, Fdd2空间群, 其骨架为具有{4⁸·5⁴·6³}拓扑结构的三维超分子网络; 化合物3属于三斜晶系, P\begin{array}{c}\bar{1}\end{array}空间群, 为1个五重穿插的三维超分子网络, 其骨架具有{4⁴·6²}拓扑结构.

Synthesis and Characterization of Novel Ni(Ⅱ) Metal-organic Frameworks with Helical Crystal Structure†

The multidenate 4,4'-(phenylazanediyl)dibenzoic acid(H₂L) ligand and nickel(Ⅱ) ions reacted with 1,3-bis(imidazol-l-yl)benzene(bib) or 4,4-bipyridine or 1,4-bis4-(1H-imidazol-l-yl)benzyl]piperazine(bibpip) under the solvothermal reactions, three new metal-organic frameworks with helical structure, namely{Ni₂L₂(bib)₂·2H₂O]·5H₂O}_n(1), Ni(HL)₂(bpy)]_n(2) and {Ni₂L₂(bibpip)₂·2H₂O]·6H₂O}_n(3), were presented along with an analysis of the structural features by single-crystal X-ray diffraction. Complexes 1—3 were also characterized by FTIR spectroscopy, elemental analyses, thermal analysis and power X-ray diffraction(PXRD). The results showed that the complex 1 crystallizes in the monoclinic space group C2/c, exhibited two-dimensional(2D) layer with {4²·6⁵·8} topology structure; complex 2 crystallizes in the orthorhombic space group Fdd2, gave a 3D framework with {4⁸·5⁴·6³} topology structure; complex 3 exhibits a 5-fold interpenetrating 3D framework with a {4⁴·6²} topology.