Syntheses, Structures, and Properties of a Series of Multidimensional Metal–Organic Polymers Based on 3,3′,5,5′-Biphenyltetracarboxylic Acid and N‑Donor Ancillary Ligands

Hydrothermal reactions of aromatic 3,3′,5,5′-biphenyltetracarboxylic
acid (H4bpt) and the transitional metal cations in the
presence of rigid or flexible N-donor ancillary ligands afford nine
novel coordination polymers, namely, [M­(H2bpt)­(Hpptp)]n (M = Mn (1), Fe (2), Co (3), and Zn (4)), [Mn2(bpt)­(Hpptp)2]n (5), {[Zn3(Hbpt)­(bpt)­(H2O)2]­[(4,4′-H2bmib)0.5]·H2O}n (6), {[Cu­(bpt)0.5(4,4′-bimbp)]·H2O}n (7), {[Co­(H2bpt)­(2,7-dfo)]·H2O}n (8), and {[Ni2(bpt)­(4,4′-bibp)2.5(H2O)]·3­(H2O)}n (9) (Hpptp = 2-(3-(4-(pyridin-4-yl)­phenyl)-1H-1,2,4-triazol-5-yl)­pyridine; 4,4′-bmib = 4,4′-bis­(2-methylimidazol-1-yl)­benzene;
4,4′-bimbp = 4,4′-bis­(imidazol-1-ylmethyl)­biphenyl;
2,7-dfo = 2,7-di­(imidazo-1-ly)-9H-fluoren-9-one;
4,4′-bibp = 4,4′-bis­(imidazol)­biphenyl). Their structures
have been determined by single-crystal X-ray diffraction analyses,
elemental analyses, IR spectra, powder X-ray diffraction (PXRD), and
thermogravimetric (TG) analyses. Complexes 1–4 are isomorphism and feature a similar 2-fold interpenetrating
2D helical double layer, which is further extended via the interlayer
π···π interactions into a 3D supramolecular
structure. Complex 5 displays a pillared-layer 3D porous
network with a (62.8)2(62.82.102) topology. Compound 6 shows an unprecedented
3D host-framework consisting of Zn6 clusters and exhibits
a novel 3D (5,5,5,6,9)-connected topological net with the Schläfli
symbol of (410.65)­(419.616.8)­(46.64)­(47.63)2. The topology of 7 is an unprecedented binodal
(4,4)-connected 3D network with the Schläfli symbol of (62.84)­(42.82)2.
Complex 8 exhibits a 3D (66) structure with
left- and right-handed helical chains arranged alternately. Complex 9 is a novel trinodal (4,4,5)-connected 3D framework with
the Schläfli symbol of (64.82)­(65.8)­(68.82). To the best of our knowledge,
the 3D frameworks with (5,5,5,6,9)-connected net for 6, binodal (4,4)-connected for 7, and trinodal (4,4,5)-connected
for 9 have never been documented to date. Moreover, the
luminescent properties of 4 and 6 have been
investigated.

以芳香族3,3′,5,5′-联苯四甲酸（3,3′,5,5′-biphenyltetracarboxylic acid, H4bpt）与过渡金属阳离子为反应物，在刚性或柔性氮供体辅助配体存在下进行水热反应，成功合成九种新型配位聚合物，分别为：[M(H₂bpt)(Hpptp)]ₙ（M = Mn(1)、Fe(2)、Co(3)、Zn(4)）、[Mn₂(bpt)(Hpptp)₂]ₙ(5)、{[Zn₃(Hbpt)(bpt)(H₂O)₂]·[(4,4′-H₂bmib)₀.₅]·H₂O}ₙ(6)、{[Cu(bpt)₀.₅(4,4′-bimbp)]·H₂O}ₙ(7)、{[Co(H₂bpt)(2,7-dfo)]·H₂O}ₙ(8)以及{[Ni₂(bpt)(4,4′-bibp)₂.₅(H₂O)]·3(H₂O)}ₙ(9)。其中，Hpptp=2-(3-(4-(吡啶-4-基)苯基)-1H-1,2,4-三唑-5-基)吡啶（2-(3-(4-(pyridin-4-yl)phenyl)-1H-1,2,4-triazol-5-yl)pyridine）；4,4′-bmib=4,4′-双(2-甲基咪唑-1-基)苯（4,4′-bis(2-methylimidazol-1-yl)benzene）；4,4′-bimbp=4,4′-双(咪唑-1-基甲基)联苯（4,4′-bis(imidazol-1-ylmethyl)biphenyl）；2,7-dfo=2,7-双(咪唑-1-基)-9H-芴-9-酮（2,7-di(imidazo-1-ly)-9H-fluoren-9-one）；4,4′-bibp=4,4′-双(咪唑)联苯（4,4′-bis(imidazol)biphenyl）。通过单晶X射线衍射分析、元素分析、红外光谱、粉末X射线衍射（PXRD）以及热重（TG）分析确定了它们的结构。配合物1~4为同构体，均具有相似的二重穿插二维螺旋双层结构，该结构进一步通过层间π···π相互作用拓展为三维超分子结构。配合物5呈现出具有(6².8)₂(6².8².10²)拓扑的柱层状三维多孔网络。化合物6展现出由Zn₆簇构成的前所未有的三维主体骨架，其拓扑为新颖的三维(5,5,5,6,9)-连接拓扑网络，施拉夫利符号（Schläfli symbol）为(4¹⁰.6⁵)(4¹⁹.6¹⁶.8)(4⁶.6⁴)(4⁷.6³)₂。配合物7的拓扑为前所未有的双节点(4,4)-连接三维网络，施拉夫利符号为(6².8⁴)(4².8²)₂。配合物8展现出具有左手和右手螺旋链交替排列的三维(6⁶)结构。配合物9为新颖的三节点(4,4,5)-连接三维骨架，施拉夫利符号为(6⁴.8²)(6⁵.8)(6⁸.8²)。据我们所知，截至目前尚未见有关具有(5,5,5,6,9)-连接网络的三维骨架（配合物6）、双节点(4,4)-连接三维骨架（配合物7）以及三节点(4,4,5)-连接三维骨架（配合物9）的文献报道。此外，本研究还对配合物4和6的发光性能进行了探究。