三个二羧酸配体配位聚合物的合成、结构表征和荧光性质

以羧酸配体 2,2''-(1,4-亚苯基双(亚苯基))双(硫二基)二苯甲酸(H₂L¹)和 2,2''-(2,3,5,6-四甲基-1,4-亚苯基)双(亚甲基）双(硫二基)二苯甲酸(H₂L²)分别与金属盐反应,通过溶剂热方法合成了 3个配位聚合物：{[Ni(L¹)(H₂O)₄]·2H₂O}_n (1)、[Zn(L¹)(DMA)₂]_n(2)和[Co(L²)(DMF)₂]_n (3),其中DMA=N,N-二甲基乙酰胺,DMF=N,N-二甲基甲酰胺。对配合物1~3进行了单晶X射线衍射、元素分析、红外光谱、热重分析、粉末X射线衍射和固体紫外可见光谱测试和表征。单晶X射线衍射表明：3个配合物均为一维锯齿形链状结构,并通过氢键作用形成三维骨架,且配体均表现为反式构象。此外,对配合物2固态荧光性质进行了研究。     

两个一维镁配位聚合物的合成、晶体结构和荧光性质

本文以Mg(NO3)2.6H2O分别与4,5-咪唑二羧酸(4,5-imidazoledicarboxylic acid,H3imdc)和3,5-吡唑二羧酸(3,5-pyrazoled-icarboxylic acid,H3pdc)通过水热反应合成了2个新型镁的一维配位聚合物[Mg(Himdc)(DMF)(H2O)]n(1)和[Mg(Hpdc)(H2O)2]n(2),并对配位聚合物1和2进行了元素分析、FTIR、热重分析和X-射线单晶结构解析等表征。X-射线单晶结构解析表明配位聚合物1和2的晶体分别属于正交晶系与单斜晶系,空间群分别为P212121和P21/c。配合物1为一维Z字型链状结构,配合物2为一维线型链状结构,2个配合物中的链与链之间均通过氢键相互作用堆积成三维结构。对1和2进行固态荧光光谱分析,结果显示,1和2的荧光发射峰与各自的配体的荧光发射峰峰形一致,说明2个配合物的荧光发射峰应归属于各自配体内的π→π*电子跃迁。     

辅助配体导向合成两个锌金属配位聚合物: 结构,稳定性和荧光性质

以二苯-4,4'-二羧酸和六水硝酸锌为原料,在相同反应条件下,通过改变不同的辅助配体(2,2'-二甲基-4,4'-联吡啶和三乙烯二胺),合成出2个金属有机配位聚合物:{[Zn(DBA)(dmbpy)_0.5]·2H₂O}_n(1)和[Zn₂(DBA)₂(dabco)]_n(2)(H₂DBA=二苯-4,4'-二羧酸,dmbpy=2,2'-二甲基-4,4'-联吡啶,dabco=三乙烯二胺)。通过元素分析、红外光谱、差热分析、X射线粉末衍射和X射线单晶衍射等手段对配合物进行了结构表征。结果显示,化合物1为二维(4,4)网络结构,2个二维结构在平行方向上通过互锁进一步形成2D→2D的互锁网络结构。化合物2为一维带状结构。热稳定性表明化合物1能够稳定到370℃;而化合物2稳定性差。荧光分析表明常温固态下配合物1和2均发射蓝色荧光,荧光寿命分别为231.4 ns和2.33 ns。     

基于双咪唑配体的一维银配位聚合物的合成、晶体结构和表征

通过水热法合成了1个一维配位聚合物[Ag(1,2-bix)].HL,并对该化合物进行了元素分析、红外和单晶X-射线表征(1,2-bix=1,2-(二亚甲基苯)二咪唑配体,HL=反式-4,4′-二羧基偶氮苯阴离子)。该化合物属于三斜晶系,空间群P1,晶胞参数a=0.937 80(5)nm,b=1.119 91(16)nm,c=1.356 36(10)nm,α=102.923(8)°,β=91.751(5)°,γ=110.792(10)°,V=1.288 5(2)nm3,Z=2,C28H23AgN6O4,Mr=615.39,Dc=1.586 g.cm-3,F(000)=624,μ(Mo Kα)=0.829 mm-1,R=0.040 7,wR=0.102 0。在该化合物中,双咪唑配体连接着中心的Ag(Ⅰ)原子形成了一维链状结构。二羧酸配体之间通过O-H…O键形成另一种一维链状结构,两种类型的链以相互垂直的方式延伸。此外,我们还仔细研究了该化合物的荧光性质。     

混合配体构筑的配位聚合物的合成、结构与荧光性质

在溶剂热条件下,利用Cd（Ⅱ）、Co（Ⅱ）在混配体体系下合成出3个结构新颖的配位聚合物[Cd₃（pic）₄（H₂bmimb）]_n（1）,[Co₃（pic）₄（H₂bmimb）]_n（2）和[Cd₂（1,2-mbix）（pic）₂（H₂O）₂]_n（3）（pic=5-苯基间苯二甲酸;H₂bmimb=1,4-二（（2-甲基咪唑）亚甲基）苯;1,2-mbix=1,2-二（（2-甲基咪唑）亚甲基）苯）,并通过单晶X射线衍射、红外光谱、热重分析、元素分析、粉末X射线衍射和荧光光谱等对配合物进行了表征。配合物1和2中金属离子Cd²⁺、Co²⁺均与pic配体形成了三维阴离子骨架,双质子化的双咪唑配体位于骨架中平衡骨架电荷。配合物3中,Cd²⁺金属中心与pic、1,2-mbix配体配位形成一维链,链与链之间通过苯环间的π…π堆积形成二维层,进而通过氢键形成三维超分子结构。配合物1和3表现出良好的荧光性质。     

混合配体构筑的配位聚合物的合成、结构与荧光性质

在溶剂热条件下,利用Cd(Ⅱ)、Co(Ⅱ)在混配体体系下合成出3个结构新颖的配位聚合物[Cd_3(pic)_4(H_2bmimb)]n(1),[Co_3(pic)4(H_2bmimb)]n(2)和[Cd_2(1,2-mbix)(pic)_2(H_2O)_2]_n(3)(pic=5-苯基间苯二甲酸;H_2bmimb=1,4-二((2-甲基咪唑)亚甲基)苯;1,2-mbix=1,2-二((2-甲基咪唑)亚甲基)苯),并通过单晶X射线衍射、红外光谱、热重分析、元素分析、粉末X射线衍射和荧光光谱等对配合物进行了表征。配合物1和2中金属离子Cd~(2+)、Co~(2+)均与pic配体形成了三维阴离子骨架,双质子化的双咪唑配体位于骨架中平衡骨架电荷。配合物3中,Cd~(2+)金属中心与pic、1,2-mbix配体配位形成一维链,链与链之间通过苯环间的π…π堆积形成二维层,进而通过氢键形成三维超分子结构。配合物1和3表现出良好的荧光性质。     

含共轭三烯吡啶配体的配位聚合物的合成、结构及荧光性质

将1,6-双（4-吡啶基）-1,3,5-己三烯（bphte）和镉盐分别与2种羧酸配体（2,5-二呋喃二甲酸（2,5-H₂FDC）及1,3,5-均苯三甲酸（1,3,5-H₃BTC））进行溶剂热反应,得到2个配位聚合物：[Cd （2,5-FDC）（bphte）（H₂O）]_n （1）和[Cd （1,3,5-HBTC）（bphte）]_n （2）。对配合物1和2分别进行了元素分析、红外光谱、单晶X射线衍射、粉末X射线衍射和热重分析表征。配位聚合物1具有spl拓扑结构的三维互穿超分子框架,而配合物2是由bphte配体交叉连接一维链[Cd₂（1,3,5-HBTC）₂]_n形成的三维结构。配合物1和2在固态时表现出不同的荧光性质。配合物2遇到水溶液中Fe³⁺会发生荧光猝灭,因此以其作为荧光探针对水溶液中Fe³⁺进行了选择性荧光检测,它对Fe³⁺的检测限可达到0.013 μmol·L^-1。这种荧光猝灭过程可归因于Fe³⁺离子的吸收带与配合物2的激发带之间存在部分重叠。     

含咪唑基配体镉配位聚合物的合成、结构及荧光性质

利用柔性含咪唑基配体1,3,5-三(咪唑-1-甲基)苯(L)与硫酸镉在溶剂热条件下反应,通过反应条件控制得到了2个配位聚合物{[Cd(L)(EG)0.5(H2O)(SO4)]·EG·H2O}n(1)和[Cd(L)(EG)(SO4)]n(2)(EG=乙二醇)。并利用元素分析、红外光谱、X射线单晶衍射等方法对其进行了表征。配合物1中配体L连接Cd(Ⅱ)形成一维链状结构,而配合物2中配体L与Cd(Ⅱ)配位形成二维网状结构,并进一步通过硫酸根桥联形成三维结构。有趣的是,EG分子在配合物1中连接链内的2个Cd(Ⅱ),而在配合物2中作为端基与1个Cd(Ⅱ)配位,硫酸根离子在1中作为端基配位,而在2中则以桥联方式连接2个Cd(Ⅱ)。研究了配合物的荧光性质及其热稳定性。     

由咪唑-4,5-二羧酸和1,4-对苯二甲酸构筑的一个三维镉(Ⅱ)配位聚合物的合成、结构及荧光性质

以CdCl2、咪唑-4,5-二羧酸(H3IDC)和1,4-对苯二甲酸(H2BDC)为原料,在水热条件下合成得到了一个新的三维镉髤配位聚合物[Cd2(HIDC)(BDC)(H2O)]n(1),通过元素分析、红外光谱、粉末X-射线衍射、热重分析和单晶X-射线衍射法等对其组成和结构进行了表征。单晶X-射线结构分析表明,在配合物1的晶体结构中含有沿a轴方向的一维无限的{[Cd2(CO2)]2(CO2)2}n配位聚合链。此聚合链再通过桥连HIDC2-与BDC2-配体的连接,最终形成一复杂的三维金属-有机框架结构。配合物1的固体室温荧光测试结果表明,在波长为350 nm的光激发下于456 nm处出现强烈的荧光发射。     

柔性配体构筑的三个构象多样的镧系羧酸配位聚合物:合成,结构和荧光性质

利用2,2''-（1,4-亚苯基）二（亚苯基）二（硫基）苯二羧酸（H₂L¹）和2,2''-（2,3,5,6-四甲基-1,4-亚苯基）二（亚甲基）二（硫基）苯二甲酸（H₂L²）2个柔性二羧酸分别与镧系金属盐反应,通过溶剂热方法合成了3个配位聚合物：{[（NH₂（CH₃）₂][Nd（L¹）₂（DMF）]·2DMF}_n（1）和{[Ln（L²）_1.5（H₂O）（DMF）₂]·2DMF}_n[Ln=Ce（2）,Pr（3）]。利用元素分析、红外、粉末X射线衍射、热重分析等对配合物进行了表征。X射线单晶衍射分析表明：3个配合物均为二维的层状结构,并且2个配体在配合物中表现出不同的构象。（L¹）^2-在配合物1中表现出顺式和反式2种构象,（L²）^2-在配合物2和3中仅表现出反式构象。此外,对配合物的热稳定性和荧光性质也进行了研究。     

Syntheses,structural diversity and properties of three coordination polymers built by chlorophenyl imidazole dicarboxylate

Two 2D coordiantion polymers, [Sr(p-ClPhHIDC)(H₂O)]_n (p-ClPhH₃IDC = 2-(4-chlorophenyl)-1H-imidazole-4,5-dicarboxylic acid) (1) and [Cd₃(p-ClPhH₂IDC)₂(p-ClPhHIDC)₂(H₂O)₂]_n (2) and one 3D polymer {[Co₃(p-ClPhHIDC)₃(H₂O)₃]·6H₂O}_n (3) have been prepared successfully under solvothermal conditions and structurally characterised by elemental analyses, IR and XRPD determinations, and have been further analysed by single-crystal X-ray diffraction. Polymer 1 exhibits a graceful 2D grid sheet structure. Polymer 2 can be regarded as a (3,3,4)-coordinated 2D network. Polymer 3 exhibits a 3D motif with 1D open channels and [Co₁₂(p-ClPhHIDC)₉] bihexagonal rings. The coordination features of the newly prepared imidazole dicarboxylate ligand, p-ClPhH₃IDC, have been discussed from both theoretical and experimental aspects. Furthermore, the solid-state photoluminescence and thermal properties of the polymers have also been investigated.     

Zinc(II) and manganese(II) coordination polymers constructed by 2-naphthyl imidazole dicarboxylate: syntheses,structures and properties

Three coordination polymers [Zn(μ₃-HNIDC)(CH₃OH)]_n (H₃NIDC = 2-(2-naphthyl)-1H-imidazole-4,5-dicarboxylic acid) (1), [Mn(μ₂-HNIDC)(4,4′-bipy)]_n (4,4′-bipy = 4,4′-bipyridine) (2) and [Mn₂(μ₂-HNIDC)₂(phen)₂]_n (phen = 1,10-phenanthroline) (3) have been solvothermally synthesised and structurally characterised by single-crystal X-ray diffraction, elemental analyses, thermal analyses and IR spectra. Polymer 1 displays a three-dimensional open architecture with one-dimensional (1D) channels. Polymer 2 exhibits a sheet structure containing infinite rectangles. Polymer 3 presents a 1D wave chain structure. The solid-state photoluminescence of 1 has been investigated as well.     

A series of 1-D, 2-D and 3-D coordination polymers self-assembled from a flexible dicarboxylate and mixed N-donor ligands: syntheses,structural diversity,and luminescent properties

We have synthesized a series of metal–organic coordination frameworks under solvothermal conditions, formulated as [Cu(L)(phen)](1), [Co₂(L)₂(bib)]·CH₃OH(2), [Co(L)(btmb)_0.5](3), [Zn(L)(bib)]·2H₂O(4), [Cu(L)(bib)]·DMF(5), and [Mn₄(L)₄(bimb)(CH₃OH)](6) based on a flexible multicarboxylic bridging ligand 4,4′-methylenebis(oxy)-dibenzoic acid (H₂L) and flexible N-donor ligands 1,4-bis (1H-imidazol-1-yl)-butane (bib), 1,4-bis(1H-1,2,4-triazol- 1-ylmethyl)benzene (btmb), and 1,4-bis(1H-imidazol-1-ylmethyl)benzene (bimb). The structures of the frameworks have been determined by single-crystal X-ray diffraction analyses and further characterized by elemental analyses, IR spectra, and thermogravimetric analyses. The crystal structure determinations reveal that 1 has a 1-D Z-shape chain. Compounds 2 and 3 are 2-D twofold parallel interpenetrating 4-connected net with the Schläfli symbol {4⁴·6²}. Compound 4 is a 2-D threefold parallel interpenetrating 4-connected nets with the Schläfli symbol {4⁴·6²}. Compound 5 is 3-D 4-connected net with the Schläfli symbol {6⁵·8}. Compound 6 is characterized by a three-dimensional framework with one-dimensional homogeneous Mn-carboxylate chain. We found that flexible carboxylate ligands have different coordination modes under different synthetic conditions. The flexible skeleton of ligands and the coordination angle between the ligand and the metal ion is described. The luminescence and thermogravimetric properties of these compounds have been investigated.     

Two new cadmium(II) coordination polymers based on imidazole‐containing ligands: synthesis,structural characterization and fluorescence properties

The judicious selection of suitable ligands is vitally important in the construction of novel metal–organic frameworks (MOFs) with fascinating structures and interesting properties. Recently, imidazole‐containing multidentate ligands have received much attention. Two new Cd^II coordination frameworks, namely, poly[tris{μ‐1,4‐bis[(1H‐imidazol‐1‐yl)methyl]benzene‐κ²N³:N^3′}tetrakis(nitrato‐κ²O,O′)dicadmium], [Cd₂(NO₃)₄(C₁₄H₁₄N₄)₃]_n, (I), and poly[[bis{μ₃‐1,3,5‐tris[(1H‐imidazol‐1‐yl)methyl]benzene‐κ³N³:N^3′:N^3′′}cadmium] hexafluorosilicate], {[Cd(C₁₈H₁₈N₆)₂](SiF₆)}_n, (II), have been synthesized and characterized by elemental analysis, IR spectroscopy and single‐crystal X‐ray diffraction. In polymer (I), the 1,4‐bis[(1H‐imidazol‐1‐yl)methyl]benzene ligand bridges Cd²⁺ ions with a distorted seven‐coordinated pentagonal bipyramidal geometry, forming a one‐dimensional ladder chain, and the nitrate anions coordinate to the Cd²⁺ ions in a terminal bidentate fashion. In the crystal, adjacent chains are further connected by C—H…O hydrogen bonds to generate a two‐dimensional (2D) supramolecular structure. Polymer (II) exhibits a 2D layered structure in which 1,3,5‐tris[(1H‐imidazol‐1‐yl)methyl] benzene ligands join Cd²⁺ centres having a six‐coordinated octahedral structure. The layers are connected by hexafluorosilicate anions via C—H…F hydrogen‐bond interactions, giving rise to a three‐dimensional supramolecular network structure in the solid state. In addition, powder X‐ray diffraction (PXRD) patterns were recorded, thermogravimetric analyses (TGA) carried out and fluorescence properties investigated.     

Synthesis,crystal structure and DNA interaction studies of three coordination polymers with mixed ligand

Three coordination polymers [Mn(Nip)(Pbim)] _n (1), [Co(Nip)(Pbim)] _n (2) and [Zn(Nip)(Pbim)] _n (3) [5-nitroisophthalate (Nip) and 2-(2-pyridyl)benzimidazole (Pbim)] were synthesised and characterised by elemental analysis, IR and single-crystal X-ray diffraction. Single-crystal X-ray diffraction analysis reveals that 1, 2 and 3 have 1-D ladder chain structures constructed from μ₃-bridge Nip ligands and metal atoms. All of these chain-like structures are finally packed into supramolecular networks through hydrogen bonds and π–π stacking interactions. Fluorescence spectral method has been used for the study on the interaction of film sperm DNA with complexes. The results show that the corresponding fluorescence spectrum appeared and the intensity was enhanced with the growth of the concentration of DNA. All of the results indicate that there exists strong interaction of the complexes with DNA.     

Synthesis,structures, and properties of a series of similar structural coordination polymers with triphosphonate anions as ligands

The hydrothermal reactions of metal precursors with aminotri(methylenephosphonic acid) yielded a series of similar structural coordination polymers of general formula {M[HN(CH₂PO₃H)₃](H₂O)₃}_n [M = Mg(II) (1), Mn(II) (2), Co(II) (3), Zn(II) (4) and Cd(II) (5)]. Compounds 1–5 were characterized by X-ray single crystal diffraction, elemental analyses, and thermogravimetric analyses. Compounds 1–5 all reveal the wave-like 1D chain structures and the structures are constructed by two types of eight-membered, square-like rings linked alternatively via the phosphonate oxygen atoms, generating double-channel systems. The magnetic studies of 2 and 3 reveal that antiferromagnetic interactions are mediated between the metal ions.     

Two cobalt coordination polymers based on an asymmetric dicarboxylate: structural diversity tuned by auxiliary ligands

Two 1-D cobalt coordination polymers, [Co(mbtx)(hpht)(H₂O)] _n (1) and [Co(mbix)(hpht)] _n (2) (mbtx?=?1,3-bis(1,2,4-triazol-1-ylmethyl)benzene, mbix?=?1,3-bis(imidazol-1-ylmethyl)benzene, H₂hpht?=?homophthalic acid), were synthesized by hydrothermal reactions and characterized by elemental analyzes, IR spectroscopy, thermogravimetry, and single-crystal X-ray diffraction. Complex 1 is a 1-D heterostranded double-helical chain as a result of bridging hpht and mbtx, and the 1-D chains are further self-assembled into a 2-D layer structure through hydrogen bonds. Complex 2 shows a 1-D molecular ladder structure, linked through C–H···π interactions to give a 2-D layer structure, which is further linked through C–H?O hydrogen bonds to form a 3-D framework. The mbtx adopts cis-conformation in 1, while for 2, mbix has trans-conformation. Factors causing the differences between 1 and 2 are discussed.     

Two zinc (II) coordination polymers based on aliphatic ether Schiff base: Synthesis,crystal structure,antioxidation and fluorescence

The synthesis of two 1D coordination polymers [Zn₂L¹₂]_n 1 and [Zn₂L²₂]_n 2 , based on the H₂L¹ (bis (salicylidene)‐3‐oxapentane‐1,5‐diamine) and the H₂L² (bis (5‐methylsalicylaldehyde)‐3‐oxapentane‐1,5‐diamine) ligands, have been described and characterized by IR, elemental analysis and X‐ray single crystal analyses. In coordination polymer 1 , each Zn²⁺ ion is five‐coordinated by three oxygen atoms and two nitrogen atoms from deprotonated ligand forming a square pyramidal configuration. It is worth noting that phenolic oxygens of the deprotonated H₂L¹ adapt monodentate and monoatomic bridging coordinated modes resulting in one‐dimensional linear chain structure in which macro rings alternately connect small rings. The coordination polymer 2 is a four‐coordinated one‐dimensional zigzag chain in which geometric structure around the Zn (II) atom can be described as distorted tetrahedron. The antioxidant activity of the coordination polymers 1 – 2 and the ligands were determined by superoxide and hydroxyl radical scavenging method in vitro. The results demonstrated that the coordination polymers exhibit more effective antioxidant activity than the ligands. Moreover, compared with emissive bands of the free ligands in the solid state and DMF solvent, the photoluminescent transition of the Zn (II) coordination polymer 1 – 2 may be attributed to ligand‐to‐ligand charge‐transfer regulated by Zn (II) ion.     

Ancillary ligand-controlled assembly of three coordination polymers: synthesis,characterization, luminescent,and catalytic properties

Abstract

By changing the ancillary ligands, three new zinc-based coordination polymers (CPs), {[Zn(4,4′-bpy)(H₂O)₄]·(TDC)·(H₂O)}_n (1), [Zn(2,2′-dmbpy)(TDC)]_n (2), and [Zn₂(3,3′-dmbpy)(TDC)₂]_n (3) (H₂TDC =2,5-thiophenedicarboxylic acid, 4,4′-bpy =4,4′-bipyridine, 2,2′-dmbpy =2,2′-dimethyl-4,4′-bipyridine, 3,3′-dmbpy =3,3′-dimethyl-4,4′-bipyridine) have been synthesized under the same reaction conditions (H₂O, pH =7–8, and 140°C) and were structurally characterized. 1 is a linear chain structure and further connected into a 3-D structure through hydrogen bonds. 2 shows a 2-D (4,4) network when the dinuclear [Zn₂(COO)₄N₂] building unit is regarded as a six-connected node. 3 has a twofold-interpenetrating 3-D zinc-organic framework pcu topology. Furthermore, 1–3 show strong photoluminescence at room temperature in the solid state, and the catalytic activities of 1–3 for degradation of methyl orange in a Fenton-like process have been investigated. The results suggest that the ancillary ligands influence the final resulting CPs.