Helical Coordination Polymers Based on A Tripodal N‐donor Ligand

The coordination polymers [Cu₂(tpim)₂] · 2H₂O ( 1 ) and [Co(H₂tpim)₂(MoO₄)₂] ( 2 ) [Htpim = 2,4,5‐tri(4‐pyridyl)‐imidazole] were synthesized. Their structures were determined by single‐crystal X‐ray diffraction and further characterized by elemental analyses, IR spectroscopy, and TG analyses. Compounds 1 and 2 both contain chiral helical‐layer structures. Compound 1 exhibits a novel 3D (3,3,4)‐connected framework with (4 · 6 · 8)(6 · 8²)(4 · 6 · 8³ · 10) topology, which is constructed from left‐ and right‐ helices. Compound 2 displays a 2D chiral helical‐layer structure which can be rationalized as a (3,6)‐connected 2D kgd (kagome dual) net, and these 2D layers are further extended by hydrogen‐bonding interactions to form a 3D supramolecular network. By comparing compounds 1 and 2 , it is believed that the tripodal N‐containing ligand (Htpim) plays a key role in the construction of helical coordination polymers. In addition, the photoluminescence property of compound 1 and the magnetic property of compound 2 were studied.     

Helical Coordination Polymers with Large Chiral Cavities

A quarter of the unit cell volume of [{Ni(4,4′‐dipy)(3‐nitrobenzoate)₂(MeOH)₂}_n], which crystallizes in the form of helices, is occupied by large chiral cavities (400–500 ų). The cavities are capable of encapsulating not only single molecules, but also face‐to‐face dimers of nitrobenzene (see stick model). 4,4′‐dipy=4,4′‐bipyridine.     

Synthesis and Structural Analysis of a Helical Coordination Polymer Formed by the Self-Assembly of a 2,2′-Bipyridine-Based exo-Ditopic Macrocyclic Ligand and Silver Cations

The overall topology of coordination polymers can be controlled by means of the coordination preferences of the metal center and the structure of the bridging ligand. This is demonstrated here by the synthesis of a single-stranded helical coordination polymer by the self-assembly of the exo-ditopic ligand 1 and silver ions.     

氮杂环配体自组装螺旋链状结构配位聚合物的研究进展

螺旋结构配位聚合物在光学装置、生物模拟化学、非对称催化化学、手性识别、生物结构等多学科领域的应用,引起了人们极大的兴趣。本文综述了氮杂环配体自组装螺旋结构配位聚合物的最新进展,按照咪唑、三唑、吡啶、嘧啶及其衍生物配体分类总结了它们构建螺旋配位聚合物的结构,并简述了通过自发手性识别过程得到纯手性螺旋配位聚合物的影响因素,展望了具有螺旋链状配位聚合物的发展前景以及其开发应用潜能。     

Synthesis,Structures, and Fluorescent Properties of Three Cobalt‐Based Coordination Polymers with a Rigid Tripodal Carboxylate Ligand

Three cobalt(II) coordination polymers, [Co₂(tatb)₂(2,2′‐bipy)₂ (H₂O)₂ · DMA · 2H₂O] ( 1 ), [Co₂(tatb)₂(1,10‐phen)₂(H₂O)₂ · 2H₂O] ( 2 ) and [Co(tatb)(1,3‐dpp) · H₂O] ( 3 ) (H₃tatb = 4,4′,4′′‐(1,3,5‐triazine‐2,4,6‐triyl)tribenzoic acid; 2,2′‐bipy = 2,2′‐bipyridyl; 1,10‐phen = 1,10‐phenanthroline; 1,3‐dpp = 1,3‐bis(pyridin‐4‐yl)propane), were synthesized solvothermally and characterized by single‐crystal and powder X‐ray diffraction (PXRD), as well as IR spectroscopy. Complexes 1 and 2 exhibit 1D double‐chain structures, which further connect into interesting 3D networks by hydrogen bond and strong π–π interactions. Complex 3 possesses 2D 4⁴‐sql topology, which is packed parallel in an AA fashion. Moreover, thermal stability properties and photoluminescence properties of 1 , 2 and 3 were also investigated.     

浅谈螺旋聚合物

螺旋聚合物广泛存在于自然界中,天然大分子如DNA、蛋白质和胶原等都呈现出神奇的螺旋结构,这些规整的二级结构对于生命体维持正常的生命活动至关重要。螺旋结构存在手性特征并具有旋光性,奇特的结构赋予了螺旋聚合物独特的性质和功能,使得螺旋聚合物在手性识别、不对称催化、手性响应和数据存储等领域显示了广阔的应用前景。本文简要介绍了螺旋聚合物研究概况,综述了动态和静态螺旋聚合物的研究进展,以及螺旋聚合物的功能和应用。     

Synthesis and crystal structures of three novel coordination polymers generated from AgCN and AgSCN with flexible N-donor ligands

The solvothermal reactions of AgX (X = CN, SCN) with mbix [mbix = 1,3-bis(imidazole-l-yl-methyl)benzene] or bix [bix = 1,4-bis(imidazole-l-yl-methyl)benzene] afforded the polymers [AgCN(mbix)]_n (1), [(AgCN)₄(bix)₂]_n (2) and [(AgSCN)₂(mbix)]_n (3). They were all characterized by infrared spectroscopy, elemental analysis and X-ray single-crystal analysis. The structure of 1 contains a 3-fold-interpenetrated 2D network, while that of 2 exhibits 2-fold parallel interpenetration. There is no interpenetration observed in 3. Compounds 2 and 3 show 3D supramolecular structures built from 2D networks through weak π ? π interactions. The photoluminescent properties of the present compounds were also investigated.     

Two Pairs of Homochiral Coordination Polymers with Helices Based on Semi‐rigid Lactic Acid Ligands

Utilizing semirigid lactic acid derivatives (R)‐H₂CBA and (S)‐H₂CBA as chiral ligands, two pair of homochiral coordination polymers formulated as [Zn((R)‐CBA)(1,4‐DIB)] · H₂O ( 1 ‐ D ), [Zn((S)‐CBA)(1,4‐DIB)] · H₂O ( 1 ‐ L ), [Co((R)‐CBA)(1,4‐DIB)] · H₂O ( 2 ‐ D ) and [Co((S)‐CBA)(1,4‐DIB)] · H₂O ( 2 ‐ L ) were prepared under solvothermal reaction condition. Single X‐ray diffraction study reveals that all the complexes are comprised of three kinds of helical chains, which are constructed by corresponding metal ions, CBA^2– ligands, and/or 1,4‐DIB ligands. Moreover, some physical characteristics, such as PXRD, thermal stabilities, solid‐state circular dichroism (CD), luminescent and magnetic properties are also investigated.     

Two Coordination Polymers based on a Flexible Tritopic Pyridyldicarboxylate Ligand: Structures and Magnetic Properties

The coordination polymers, [Ni(L)₂]_n ( 1 ) and [Mn₂(L)₂(DMF)₂(H₂O)]_n ( 2 ) were synthesized by using a tritopic ligand 5‐(4′‐carboxylphenoxy)nicotinic acid (H₂L). The structural analysis shows that compound 1 exhibits a ten‐connected three‐dimensional (3D) architecture with the point symbol 3¹².4²⁶.5⁷, 2 displays an eight‐connected topology network with a point symbol of 4²⁴.6⁴. The structures and formulas of 1 and 2 were determined by X‐ray diffraction, elemental analysis, and thermogravimetric analysis (TGA). In addition, the magnetic behaviors for 1 and 2 were investigated.     

Two New Coordination Polymers with UO22+ Units and Fluorinated Aromatic Carboxylate Linkers

A new coordination polymer, namely ²_∞[(U^VIO₂)₂(L)(DMA)₃] ( 1 ) (C2/c, Z = 8) with L = 4-monofluorobiphenyl-3,3',5,5'-tetracarboxylate (4-mF-BPTC^4–) was synthesized by solvothermal reaction in DMA (N,N'-dimethylacetamide). Its crystal structure was solved and refined from single-crystal X-ray diffraction data. It contains two different types of UO₂²⁺ units, which are connected by fluorinated tetracarboxylate ligands to form a layered structural motif. Three DMA molecules are coordinated to one UO₂²⁺ unit (CN = 7), whereas the other is solely coordinated by oxygen atoms of the tetracarboxylate linkers (CN = 8). The layers are held together by van der Waals interactions, which do not include any hydrogen bonds. An isostructural coordination polymer is formed with L' = 4,4'-difluorobiphenyl-3,3',5,5'-tetracarboxylate (4,4'-dF-BPTC^4–), as confirmed by XRPD (X-ray powder diffraction), IR/Raman spectroscopy and elemental analysis. The DSC/TG analyses of both compounds show that they are stable up to approx. 300 °C in an inert argon atmosphere.     

Effect of Polycarboxylate Coligands from Linear to V‐shaped CuII Coordination Polymers Based on a Rigid Tripodal Ligand

The layered Cu^II coordination polymer {[Cu(tib)₂(H₂O)₂](NO₃)₂} ( 1 ) based on the rigid tripodal 1,3,5‐tris(1‐imidazolyl)benzene (tib) ligand was synthesized by hydrothermal methods. By introducing different polycarboxylate coligands from linear 4,4′‐biphthalic acid (H₄L¹) to V‐shaped thiophene‐2,5‐dicarboxylic acid (H₂L²), two new copper(II) compounds were obtained, namely, {Cu(tib)(H₂L¹)(H₂O) · 3H₂O} ( 2 ) and {Cu(tib)(L²) · 3H₂O} ( 3 ). X‐ray diffraction analyses reveal that compound 2 displays a hydrogen‐bonded three‐dimensional (3D) supramolecular structure, in which protonated {H₂L¹}^2– ligands occupy some coordination sites around the metal atoms to form one‐dimensional (1D) chain by blocking the formation of two‐dimensional (2D) Cu‐tib layer as in compound 1 . Interestingly, compound 3 features a rare twofold interpenetrating binodal seh ‐3,5‐P4₃2₁2 topological network by synergistic effect of V‐shaped carboxylate group and functionally complementary N‐donor ligand. These compounds were characterized by elemental analyses, thermogravinetric analyses, and photoluminescent spectroscopy.     

Diorganotin Sulfonate and Phosphonate-Based Coordination Polymers

Abstract

Mixed-ligand diorganotin complexes, R₂Sn(L)(L¹), bearing hydrogenphosphonate and alkanesulfonate ligands as well as trinuclear tin clusters of the composition [(R₂Sn)₃(R¹PO₃)₂(L¹)₂] are the simple molecular constructing units for the synthesis of a wide variety of organotin based two- and three-dimensional coordination polymers. Synthetic aspects and structural chemistry of these new classes of metal-organic frameworks (MOFs) are presented.

GRAPHICAL ABSTRACT     

两个基于半刚性双甲基苯并咪唑配体的螺旋型镉配位聚合物

以1,4-双（2-甲基苯并咪唑-1-亚甲基）苯（bmb）为主配体与Cd（NO₃）₂反应,通过改变辅助双羧酸配体2个羧基间的连接基团,得到了2个配位聚合物{[Cd（bmb）（tba）]·DMF}_n（1）和[Cd（bmb）（ada）]_n（2）（H₂tda=5-叔丁基间苯二甲酸,H₂ada=1,3-金刚烷二乙酸）。结构分析表明聚合物1显示二维三明治结构,带有交替的左手和右手螺旋链。聚合物2也显示了二维三明治结构,带有meso-螺旋和微孔。聚合物1和2都显示了强的荧光发射和高的热稳定性。     

Structural Variability and Gas Adsorption Properties of Coordination Polymers Constructed with Aromatic Multicarboxylic and Bidentate Ligands

The self‐assembly reactions of transition metal ions and 1,3,5‐benzenetricarboxylic acid (H₃btc) in the presence of auxiliary aromatic bidentate ligands 1,10‐phenanthroline (1,10‐phen) or 4,4′‐bipyridine‐N,N′‐dioxide (4,4′‐bpdo) have isolated four coordination polymers [Co₁₈(btc)₁₀(H₂O)₆(OH)₆(1,10‐phen)₆] · 14H₂O · 3DMF ( 1 ) and [M₃(btc)₂(H₂O)₄(4,4′‐bpdo)] · 2H₂O · 2DMF [M = Co ( 2 ), Mn ( 3 ), Ni ( 4 )]. Single‐crystal X‐ray diffraction analysis revealed that the M₃ clusters in the structure of 1 – 4 are connected by hydroxyl group oxygen atoms (or oxygen atoms from 4,4′‐bpdo ligands) and carboxyl groups to generate a three‐dimensional framework. The network of final assemblies can be adjusted by varying the type of auxiliary ligands (1,10‐phen, 4,4′‐bpdo). In addition, the gas adsorption properties of 2 are also investigated.     

两个基于半刚性双甲基苯并咪唑配体的螺旋型镉配位聚合物

以1,4-双（2-甲基苯并咪唑-1-亚甲基）苯（bmb）为主配体与Cd（NO₃）₂反应,通过改变辅助双羧酸配体2个羧基间的连接基团,得到了2个配位聚合物{[Cd（bmb）（tba）]·DMF}_n（1）和[Cd（bmb）（ada）]_n（2）（H₂tda=5-叔丁基间苯二甲酸,H₂ada=1,3-金刚烷二乙酸）。结构分析表明聚合物1显示二维三明治结构,带有交替的左手和右手螺旋链。聚合物2也显示了二维三明治结构,带有meso-螺旋和微孔。聚合物1和2都显示了强的荧光发射和高的热稳定性。     

Two New Zinc(II) Coordination Polymers Based on 1, 6‐Bis(2‐methyl‐imidazole‐1‐yl)‐hexane Ligand: Synthesis,Structures, and Properties

Two coordination polymers based on 1, 6‐bis(2‐methyl‐imidazole‐1‐yl)‐hexane (bimh), namely {[Zn₃(BTC)₂(bimh)] · (bimh)}_n ( 1 ) and {[Zn(IPA)(bimh)] · (CH₃CH₂OH)_0.5}_n ( 2 ) (H₃BTC = trimesic acid, H₂IPA = isophthalic acid), were synthesized through hydrothermal reactions. In compound 1 , the zinc(II) ions are bridged by BTC^3– ligands to form an undulating infinite two‐dimensional (2D) polymeric network. The 3D networks of 1 show a twofold interpenetrating net. In compound 2 , zinc(II) ions are bridged by IPA^2– ligands to form one‐dimensional (1D) helical structures. The 2D structures of 2 are further assembled into 3D networks through aromatic π–π stacking interactions. Both compounds exhibit strong photoluminescence at room temperature and may be good candidates for potential luminescence materials.     

Crystal Structure and Solution Behavior of a Novel Enantiopure Helical Coordination Polymer Based on Binaphthyl-bisbipyridine Ligand

An enantiopure helical coordination polymer AgPF6·(R)-3 as crystalline solid was synthesized by the self-assembly of chiral binaphthyl-based ligand(R)-6,6'-di[6-(2,2'-bipyridyl)]-2,2'-diethoxyl-1,1'-binaphthalene [(R)-3] and Ag+ ion.The single crystal structural analysis indicates that this polymer exhibits an infinite cylindric single-stranded M-helical structure with local Λ configuration at each tetrahedral metal center.However,the extended structure is dissociated into some oligomeric fragments in solution.The 1H NMR spectra of complex AgPF6·(R)-3 show that the ligand possesses a good C2 symmetry,and the chemical shifts of the protons depend on the concentration and temperature.In addition,there are rapid dynamic exchanges among some oligonuclear fragments in the solution of AgPF6·(R)-3.     

Spatial and Surface Design of Porous Coordination Polymers

A significant challenge in the development of porous coordination polymers (PCP's), beyond control of pore size, is control of the shape and chemical nature of the pores. This short review presents some compounds that illustrate these features and general approaches to their preparation.     

Syntheses,structures of Mn(II), Ni(II), Cu(II) and Zn(II) coordination complexes based on 3,4,5-trifluorobenzeneseleninic acid and N-donor ligands

Abstract

Five new coordination complexes [Mn^II (L₁)₂(4,4′-bpy)]_n (1), [Ni^II (L₁)₂(4,4′-bpy)]_n (2), [Zn^II (L₁)₂(4,4′-bpy)]_n (3), [Cu^II (L₁)₂(phen)₂]Cl₂ (4) and [Cu^II ₂(L₁)₂(2,2′-bpy)₂]Cl₂ (5) (HL₁?=?3,4,5-trifluorobenzeneseleninic acid, 4,4′-bpy = 4,4′-bipyridine, 2,2′-bpy = 2,2′-bipyridine and phen = 1,10-phenanthroline), have been synthesized and characterized by single-crystal X-ray diffraction, powder X-ray diffraction (PXRD), elemental analysis and IR spectroscopy. Complexes 1–3 display similar layers structures. In 1–3, the adjacent layers are further connected through π···π interactions to form three-dimensional supramolecular structures. Complexes 4 and 5 show a dimer containing an eight-membered ring. The dimer extends into three-dimensional supramolecular structures through π···π interactions, C–H···F and C–H···Cl interactions.