Syntheses and physical properties of three-dimensional coordination polymers with the flexible tripodal ligand 1,3,5-tris(1,2,4-triazol-1-ylmethyl)benzene

Two 3D organic–inorganic hybrid coordination polymers, [M₂(ttmb)₂(SO₄)₂(H₂O)₂] · 7H₂O (M = Cd, 1; M = Mn, 2; ttmb = 1,3,5-tris(1,2,4-triazol-1-ylmethyl)benzene), have been synthesized and structurally characterized. They are isostructural and possess a 3D architecture fused from 2D (4,4) M(ttmb) networks and MSO₄ chains by sharing “hinge” metal atoms. The thermal properties of 1 and 2, luminescent property of 1 as well as magnetic property of 2 have been investigated.     

Syntheses,structures and luminescence of zinc and cadmium coordination polymers with bis(1,2,4-triazol-1-yl)butane and benzenedicarboxylate

The self-assembly reactions of the flexible ligand 1,4-bis(1,2,4-triazol-1-yl)butane (btb) and rigid ligand 1,4-benzenedicarboxylate (bdc) with Zn(II) or Cd(II) give two novel coordination polymers {[Zn(bdc)(btb)](H₂O)₅}_n (1) and {[Cd₂(bdc)₂(btb)(H₂O)₂](H₂O)₇}_n (2). Coordination polymer 1, a supramolecular isomer of [Zn₂(bdc)₂(btb)₂](H₂O)₂ [X.L. Wang, C. Qin, E.B. Wang, Z.M. Su, Chem. Eur. J. 12 (2006) 2680], is a special 2D (6,3) network, with six Zn(II) atoms at six corners and four bdc and two double btb at six edges. Coordination polymer 2 exhibits a distorted 3D cubic topology that is built from dimer Cd₂ units. The blue luminescent emission maxima at 420 and 439 nm for 1, 440 and 455 nm for 2 were observed in the solid state at room temperature.     

Syntheses,structures and photocatalytic properties of three copper(II) coordination polymers

Three coordination polymers [Cu₂(obtz)₂(tdc)₂]_n (1), {[Cu(obtz)₂(H₂O)₂][Cu₂(obtz)₂(sip)₂]5.5H₂O}_n (2) and [Cu(obtz)(nip)]_n(3) were synthesized by the hydrothermal reaction (obtz = 1.2-bis(1,2,4-triazol-1-ylmethyl)benzene, tdc = 2.5-thiophenedicarboxylate, sip = 5-sulfoisophthalate, nip = 5-nitroisophthalate). 1 shows a ladder-like one-dimensional chain with two side arms. 2 is comprised of two distinct and crystallographically independent polymeric motifs. The first motif in 2 is the ladder-like one-dimensional anionic chain with two side arms. The second motif in 2 is the cationic chain. 3 exhibits the intriguing 2-fold interpenetrated network based on the undulated 2D (4.4) network. 1, 2 and 3 are good photocatalysts for the degradation of methyl orange (MO) under UV irradiation.     

Syntheses,structures and luminescence of two cadmium entangled coordination polymers based on bis(imidazole) and biscarboxylate ligands

Two entangled coordination polymers [Cd₂(bib)(bdc)₂]_n (1) and [Cd₂(bib)(bda)₂]_n (2) were synthesized by the hydrothermal reaction (bib = 1,4-bis(2-methyl-imidazol-1-yl)butane, bdc = 1,2-benzenedicarboxylate, bda = 1,4-benzenediacetate). 1 exhibits an unusual 6-connected self-catenated 3D network based on Cd₂(COO)₂ dimer with the point symbol of (4⁴·6¹⁰·8). 2 exhibits a 3-fold interpenetrating 3D pcu network based on Cd₂(COO)₂ dimer. The different conformations of bib ligands (the anti–anti–anti conformation in 1 and gauche–anti–gauche conformation in 2) play the key role in the construction of different structures in 1 and 2. The luminescence and thermal stability were investigated.     

Two Cd(II) coordination polymers based on 3,6-bis(imidazol-1-yl)carbazole: Syntheses,structures and photocatalytic properties

Hydrothermal reactions of CdCl₂·2.5H₂O with 3,6-bis(imidazol-1-yl)carbazole (bmcz), 2-amine-1,4-benzenedicarboxylic acid (2-NH₂-1,4-H₂BDC) or 1,4-naphthalenedicarboxylic acid (1,4-H₂NDC) afforded two coordination polymers, [Cd(2-NH₂-1,4-BDC)(bmcz)]_n (1) and [Cd(1,4-NDC)(bmcz)]_n (2). Complexes 1 and 2 were characterized by elemental analysis, IR, powder X-ray diffraction, and single-crystal X-ray diffraction. 1 and 2 are isomorphic and exhibit 3D supermolecular structures. The solid state luminescent and optical properties of 1 and 2 at ambient temperature were also investigated. A comparative study on their photocatalytic activity toward the degradation of methylene blue in polluted water was explored.     

Two nickel coordination polymers with flexible ligand 1,3,5-tri(1,2,4-triazol-1-ylmethyl)-2,4,6-trimethylbenzene

The reaction of 1,3,5-tri(1,2,4-triazol-1-ylmethyl)-2,4,6-trimethylbenzene (ttmb) with Ni(II) salts yields two coordination polymers [Ni₃(ttmb)₂(H₂O)₆Cl₆](H₂O)₃ (1) and [Ni(ttmb)₂(H₂O)₂](NO₃)₂(H₂O)₄ (2). The flexible ligand ttmb shows the cis,cis,cis-conformation and a tri-monodentate coordination mode in 1. Each ttmb links three Ni(II) atoms to form an undulated (3, 4)-connected two-dimensional network. Each undulated two-dimensional network polycatenates other two identical networks, thus giving a rare (2D → 3D) parallel polycatenation network in 1. The ttmb ligand exhibits the cis,trans,trans-conformation and a two-monodentate coordination mode in 2. Each ttmb connects two Ni(II) atoms to construct a two-dimensional (4, 4) network in 2. The thermal stability of compounds 1 and 2 was studied.     

Syntheses,structures and photoluminescence properties of two 2D Cd(II) coordination polymers based on a semirigid tridentate N-donor ligand

The assembly of a semirigid tridentate N-donor ligand with Cd(II) ions afforded two novel coordination polymers, [Cd(tipa)(H₂O)₂·2NO₃·2DMF·H₂O]_n (1), [Cd₂(tipa)₂Cl₄·2DMF·6H₂O]_n (2), where tipa = tris(4-(1H-imidazol-1-yl)phenyl) amine. Structural analyses indicate that the two compounds feature 2D layered networks. A 3-connected uninodal net with point symbol of (8²·10) is constructed in compound 1 by the connection of tipa and metal ions, in which the terminally coordinated water molecules prevent further extension of the layer. Compound 2 features [Cd₂Cl₄] motifs, which are bridged by tridentate tipa ligands into a 2D (3,6)-connected layer. The results show that tipa with different dihedral angles between benzene ring and terminal imidazole groups can act as versatile building blocks for the generation of various networks. Moreover, the photoluminescence properties of 1 and 2 in the solid state at room temperature have been investigated.     

Syntheses,crystal structures,and magnetic studies of two cobalt(II) coordination polymers based on concurrent ligand extension

An ether bridged tetracarboxylic acid ligand, 5-(3′,4′-Dicarboxylphenoxy)-isophthalic acid (H₄L) was used to construct two Co(II) coordination polymers in presence of different nitrogen donor ligands such as 4,4′-bipyridine (4,4′-bpy) and 4,4′-bis(pyrid-4-yl)biphenyl (bpbp). The products formed under hydrothermal conditions are formulated as [Co₂L(4,4′-bpy)₂(H₂O)₃]_n (1) and {[Co(bpbp)₂(H₂L)]·H₂O}_n (2). The compounds were characterized by single-crystal X-ray diffraction, IR spectroscopy, elemental analysis, and powder X-ray diffraction (PXRD) measurement. Compound 1 shows an intriguing (3,4,5)-connected 3D framework with a point symbol of (4² · 6² · 8²)(4² · 6⁵ · 8³)(6² · 8). Compound 2 is an unusual 3D supramolecular framework generated by the one-dimensional [Co(bpbp)(H₂L)]_n polymer chain. The magnetic properties of compounds 1 and 2 were examined, indicating antiferromagnetic interactions between the cobalt(II) ions in the temperature range of 2–300 K.     

A novel three-dimensional network silver coordination polymer with flexible bis(1,2,4-triazol-4-yl)ethane

The self-assembly reaction of the flexible ligand 1,2-bis(1,2,4-triazol-4-yl)ethane (btre) and AgClO₄ gives a novel coordination polymer {[Ag(btre)](ClO₄)}_n (1). Adjacent two silver(I) atoms are linked through four nitrogen atoms of two N1/N2 atoms of two btre ligands and form Ag₂N₄ 6-membered rings and construct a one-dimensional chain. The chains extend through btre bridges in four different directions alternatively to construct a novel three-dimensional network. Compound 1 exhibits luminescence emission maxima at 326 nm upon excitation at 260 nm in the solid state at room temperature. The anion exchange of compound 1 with BF₄^? and NO₃^? occurs smoothly in a typical aqueous media.     

Assembly of two ferrous coordination polymers with triazole derivative: Syntheses,structures and magnetic properties

The reactions of Fe(II) salts with 1,4-bis(1,2,4-triazole-1-ylmethyl-benzene) (btx) give two new Fe(II) coordination polymers {[Fe(btx)₃](ClO₄)₂}_n (1) and {[Fe(btx)(SO₄)(H₂O)₂]}_n (2), which have been characterized by element analysis, PXRD, single-crystal X-ray diffraction and magnetic susceptibility. 1 shows infinite plait-like chain structure, while 2 exhibits as 2D grid. Magnetic studies indicate that the Fe(II) ions in the two coordination polymers retain in high-spin ground state upon cooling from 300 to 2 K, showing antiferromagnetic interactions.     

Syntheses and crystal structures of novel silver(I) coordination polymers based on linear or tetrahedral coordination environments

Two coordination polymers containing Ag(I) atoms, {[Ag(3-pia)](PF₆)}_n (1) and {[Ag(3-pia)₂](PF₆)}_n (2) (3-pia = N-pyridin-3-yl-isonicotinamide), have been synthesized using different solvents, and characterized by single X-ray analyses. In compound 1, Ag(I) atoms are linearly coordinated by two 3-pia ligands, resulting in one-dimensional chains. On the other hand, in compound 2, Ag(I) atoms are tetrahedrally coordinated by four 3-pia ligands, resulting in two-dimensional sheets.     

Syntheses,structures and properties of chiral Ln(III) coordination polymers based on (R)-4-(4-(1-carboxyethoxy)phenoxy)-3-fluorobenzoic acid

Two isomorphic chiral lanthanide coordination polymers (CCPs), namely, [Ln₂(cpfa)₃]_n {Ln = Yb Xu et al. (2011) and Lu Zheng et al. (2015) } {H₂cpfa = (R)-4-(4-(1-carboxyethoxy)phenoxy)-3-fluorobenzoic acid, have been synthesized under hydro(solvo)thermal conditions. Their structures have been determined by single-crystal X-ray diffraction analyses and further characterized by infrared spectra (IR), powder X-ray diffraction (PXRD), elemental analyses, thermogravimetric (TG) analyses and circular dichroism spectra (CD). Structure analysis reveals that CCPs 1 and 2 are isomorphic, crystallizing in Orthorhombic space group P2₁2₁2₁ and giving 3D rhombic framework. Further, CCP 1 show the strong NIR luminescence of Yb(III) ions, suggesting that [cpfa]^2 − is able to sensitize the luminescence of lanthanide ions efficiently. The two polymers also exhibit modest SHG efficiency indicating their potential application as optical materials. Thermogravimetric analyses show the remarkable thermal stabilities of the two lanthanide 3D frameworks up to 420 °C.     

Three new coordination polymers based on 4-oxo-1(4H)quinolineacetate: Synthesis,structures and luminescent properties

Reactions of 4-oxo-1(4H)-quinolineacetic acid (Hoqa) and varied metal salts of Zn(II), Cd(II) and Ag(I) resulted in the formation of three new coordination polymers, namely, [Zn(oqa)₂]·H₂O (1), [Cd(bpy)(oqa)₂(H₂O)₂]·4H₂O (2) and [Ag(bpy)(oqa)]·2H₂O (3) (bpy = 4,4′-bipyridine). Complex 1 has a three-dimensional (3D) polymeric network with diamondoid topology; compounds 2–3 exhibit one-dimensional (1D) chain structure characteristics, which are further assembled through π–π stacking attractions and hydrogen bonds, forming the 3D supramolecular frameworks. In addition, the solid-state luminescent properties of the ligand Hoqa and complexes 1–2 have been investigated at room temperature.     

Syntheses,structures and properties of novel d10 coordination polymers based on 4-[(1H-imidazol-4-yl)methylamino]benzoic acid ligand

Complete and partial deprotonation of new ligand 4-[(1H-imidazol-4-yl)methylamino]benzoic acid (H₂L) under hydrothermal conditions lead to the formation of two novel coordination polymers [ZnL]_n (1) and [Ag(HL)]_n (2). Complex 1 displays a rare three-dimensional (3,6)-connected rtl framework with (4 · 6²)₂(4² · 6¹⁰ · 8³) topology, while 2 has a one-dimensional chair-like structure including significant argentophilic Ag–Ag interactions. Both 1 and 2 show remarkable thermal stability and complex 1 was found to show strong blue luminescence with emission maxima at 381 nm upon excitation at 347 nm in the solid state at room temperature.     

Two novel 3D self-threading coordination polymers with CdSO4 topology: Syntheses,structures and properties

Two new isostructural metal-organic frameworks, namely [Co(HL)(bpp)] · 0.5H₂O (1) and [Zn(HL)(bpp)] · 3H₂O (2) (H₃L = 5-(2′-carboxy-biphenyl-4-ylmethoxy)-isophthalic acid, bpp = 1,3-bis(4-pyridyl)propane), have been hydrothermally synthesized and further characterized by single crystal X-ray diffraction, powder X-ray diffraction, elemental analyses, IR spectra and TG analyses. Compounds 1 and 2 exhibit interesting 3D frameworks of (6⁵.8)-CdSO₄ topology with dangling arm (i.e. the uncoordinated 2′-carboxy-biphenyl-4-ylmethoxy group of HL ligand). The remarkable feature of these two compounds is that each dangling arm threads into two 6-membered rings belonging to the 3D net itself, displaying the self-threading character. The magnetic properties of 1 and photoluminescence of 2 have also been investigated.     

Syntheses,structures, and luminescent properties of zinc(II) complexes assembled with aromatic polycarboxylate and 1,3-bis(1,2,4-triazol-1-yl)propane

Three new coordination compounds, {[Zn(btrp)(ip)]?2H₂O}_n (1), {[Zn(btrp)(hip)]?2H₂O}_n (2), and {[Zn_1.5(btrp)(btc)(H₂O)]?H₂O}_n (3) (btrp = 1,3-bis(1,2,4-triazol-1-yl)propane, H₂ip = isophthalate, H₂hip = 5-hydroxy isophthalate, H₃btc = benzene-1,3,5-tricarboxylic acid) have been prepared via solvothermal method and characterized by single crystal X-ray diffraction and elemental analysis. 1 possesses 2D (4. 4) net framewok. 2 is also a 2D infinite layer framework, and the resulting 2D structure is interconnected by hydrogen-bond and π…π interactions to lead to a 3D supramolecular architecture. 3 exhibits a novel 2D framework with three nonequivalent points, {5.6²}{5².6}{5⁴.8²}. The fluorescence properties of 1–3 have been studied at room temperature.     

实验筛选分离对氰基苄氯与1-(4-氰基苄基)-1H-1,2,4-三氮唑两种化合物的溶剂

为筛选分离对氰基苄氯和1-(4-氰基苄基)-1H-1,2,4-三氮唑较好的溶剂,采用静态平衡法测定了两种化合物在不同溶剂中的溶解度数据,为工业结晶分离工艺设计提供了基础数据.由分离系数的大小选出较好的溶剂,依次为乙酸乙酯、异丙醚和四氯化碳.采用λ-h方程对两种化合物在乙酸乙酯、异丙醚和四氯化碳溶剂中的溶解度数据进行了关...     

Syntheses, structures, and photoluminescence of two Cd(II) coordination polymers constructed from analogue (pyridyl)imidazole derivative and polycarboxylate acid

Two novel Cd(II) coordination frameworks based on a semirigid asymmetric ligand L and aromatic multi-carboxylate ligands, {[Cd₂L(btc)(H₂O)₂]·5H₂O}_n (1) and [Cd₂L₂(bdc)]_n (2) (L = (4-((2-(pyridine-2-yl)-1H-imidazol-1-yl)methyl)benzoic acid, H₃btc = 1,3,5-benzenetricarboxylic acid, H₂bdc = 1,3-benzenedicarboxylic acid), have been hydrothermally synthesized, and structurally characterized by elemental analysis, IR spectroscopy, single-crystal X-ray crystallography. Due to various coordination modes and conformations of the semirigid asymmetric ligand, and carboxylate containing co-ligands, therefore, the two complexes exhibit structural and dimensional diversity. Complex 1 exhibits a novel 2D (3, 5)-connected network structure with (3·5²)(3²·5³·6⁴·7) topology. Complex 2 exhibits a novel 3D CdSO₄ topology, which is formed from different dinuclear cadmium units. In addition, the photoluminescence properties of the free ligand L, and complexes 1 and 2 were studied in the solid state at room temperature.     

Syntheses and properties of polyimides based on bis(p-aminophenoxy)biphenyls

Three biphenyl unit-containing diamines,4,4-bis(p-aminophenoxy)biphenyl (III_a), 2,2-bis(p-aminophenoxy)biphenyl (III_b), and 3,3,5,5-tetramethyl-4,4-bis(p-aminophenoxy)biphenyl (III_c), were prepared by the chlorodisplacement ofp-chloronitrobenzene with 4,4-biphenol (I_a), 2,2-biphenol (I_b), and 3,3,5,5-tetramethyl-4,4-biphenol (I_c), respectively, giving the corresponding bis(nitrophenoxy) compounds II_a-c, followed by catalytic reduction with palladium (Pd) and hydrazine. Three series of polyimidesp-PI,o-PI, and Me-PI were prepared from diamines III_a-c and aromatic tetracarboxylic dianhydrides via a two-stage procedure that included ring-opening polyaddition to give poly(amic acid)s followed by thermal cyclodehydration to polyimides. The resultant three series of poly(amic acid)s had inherent viscosities of 1.09–2.83, 0.78–1.93, and 1.55–3.09 dL/g, respectively. Almost all the poly(amic acid)s could be solution-cast and thermally converted into transparent, flexible, and tough polyimide films. All the polyimides were characterized by solubility, tensile test, wide-angle X-ray scattering measurements, differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). Effects of the structures of aromatic diamines and dianhydrides on the properties of polyimides were investigated.