Synthesis,crystal structure,and characterization of two lanthanide coordination polymers based on isonicotinate ligand

Two new europium complexes [Eu(inic)₃(H₂O)] (1) and [Eu(inic)₃] (2) [inic = isonicotinate] have been structurally determined by single-crystal X-ray diffraction and characterized by elemental analysis, infrared spectroscopy, fluorescence, and thermogravimetric analysis. In the two complexes, bifunctional isonicotinate ligands interlink europium metal ions to construct 2-D (for 1) and 3-D (for 2) coordination polymeric networks.     

Synthesis, crystal structure, and porosity estimation of hydrated erbium terephthalate coordination polymers

The reaction of the Er3+ ion with polycarboxylate ligands in gel media leads to coordination polymers exhibiting various structural types and dimensionalities. Five Er3+/1,4-benzenedicarboxylate-based coordination polymers have been obtained in such conditions. Four out of the five are new. Their crystal structures are reported and compared herein. Compound 1, namely, Er2Ter3(H2O)6, where H2Ter symbolizes the terephthalic acid, crystallizes in the space group P1 (No. 2) with a = 7.8373(10) A, b = 9.5854(2) A, c = 10.6931(2) A, alpha = 68.7770(8) degrees, beta = 70.8710(8) degrees, and gamma = 75.3330(12) degrees. It has already been reported elsewhere. The last four compounds are new. Compound 2, namely, Er2Ter3(H2O)6 x 2 H2O, crystallizes in the space group P121/a1 (No. 14) with a = 6.7429(2) A, b = 22.4913(7) A, c = 9.6575(3) A, and beta = 91.6400(18) degrees. Compound 3, namely Er2Ter3(H2O)8 x 2 H2O crystallizes in the space group P1 (No. 2) with a = 7.5391(2) A, b = 10.0533(3) A, c = 10.4578(3) A, alpha = 87.7870(10) degrees, beta = 82.5510(11) degrees, and gamma = 86.2800(16) degrees. Compound 4, namely, Er2Ter3(H2O)6 x 2 H2O crystallizes in the space group C2/c (No. 15) with a = 38.5123(13) A, b = 11.1241(4) A, c = 7.0122(2) A, and beta = 98.634(2) degrees. Compound 5, namely, Er2Ter3(H2O)6 x H2O, crystallizes in the space group P1 (No. 2) with a = 6.8776(10) A, b = 11.0420(2) A, c = 18.5675(3) A, alpha = 84.7240(6) degrees, beta = 81.8380(6) degrees, and gamma = 84.1770(8) degrees. A computational method has also been developed to evaluate the potential porosity of the coordination polymers. This method is described and then applied to the different Er2Ter3(H2O)n coordination polymers previously described.     

Synthesis, crystal structure and photoluminescent properties of four lanthanide 5-nitroisophthalate coordination polymers

Four new lanthanide coordination polymers, [Y(Hnip)(nip)(H₂O)]·H₂O (1), [Ln(Hnip)(nip)(H₂O)₂]·2H₂O [Ln=Eu(2), Tb(3)] and [Y(nip)₂]·(H₂4,4′-bpy)_0.5 (4) [5-nip=5-nitroisophthalate, 4,4′-bpy=4,4′-bipyridine], have been hydrothermally synthesized and structurally characterized. Compound 1 features novel lanthanide-carboxylate groups chains composed of three samehanded helical strands intersecting each other through hinged lanthanide atoms, and these chains are cross-linked by phenylene moieties of carboxylate ligands into a 2D layer structure. Compounds 2 and 3 are isomorphous, and contain 1D catenanelike Ln-O-C-O-Ln chains, which are interconnected by phenylene moieties into 2D layer structures. Compound 4, however, displays a 3D architecture sustained by strong hydrogen bonding interactions between the protonated 4,4′-bpy and the carboxyl oxygen atom from [Y₂(nip)₄]²⁻ with 2D layer structure, and 4,4′-bpy as the guest molecules exist in bilayer channel. The studies for the thermal stabilities of the four compounds show that compound 4 is more stable than other compounds. Compound 2 emits characteristic red luminescence of Eu³⁺ ions at room temperature, and its luminescent lifetime and quantum efficiency has been determined.     

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.     

两种由萘二酰亚胺衍生物构建的配位聚合物的合成、结构和光致变色性能

具有可逆颜色变化和适当变色寿命的光致变色材料对于无墨水和可擦除打印技术十分重要。我们将1,4,5,8-萘四羧酸二酐与甲硫氨酸结合,设计了一种基于 1,4,5,8-萘二酰胺(NDI)的桥联有机配体(H₂ncm),并以 Zn²⁺和 H₂ncm为原料,通过溶剂热反应合成了2种配位聚合物。化合物[Zn(ncm)(H₂O)₄]·2DMF (1)包含1个Zn²⁺、1个ncm^2-配体、4个配位水分子和2个DMF分子。Zn²⁺处于八面体的配位环境中,并通过 ncm^2-配体连接形成链状结构。化合物[Zn₂(ncm)₂(H₂O)₄] (2)包含 2个 Zn²⁺、2个 ncm^2-配体和4个配位水分子。2个Zn²⁺原子通过2个羧基桥联形成双核结构,并进一步通过ncm^2-配体连接形成二维层结构。2显示出从黄色到深棕色的光致变色现象。这种光诱导产生的颜色可以稳定至少3周,但在70 ℃加热时在5 min内即可恢复本来的颜色。我们证明了这种光致变色是源于光照射下NDI·自由基的产生。     

Synthesis, crystal structure and magnetism study on novel one-dimensional Cu(II) coordination polymers with 2,5-dimethylpyrazine-1,4-dioxide as bridging ligand

A novel one-dimensional coordination polymer [Cu(μ _1,6-dmpzdo)(dmpzdo)₂]·(ClO₄)₂ (dmpzdo = 2,5-dimethylpyrazine-1,4-dioxide) has been synthesized and its crystal structure determined by X-ray crystallography. In the complex each Cu1 atom is located in a square planar coordination environment with two oxygen atoms O2 and O2A from two dmpzdo terminal ligands, and two other oxygen atoms O3 and O3A from two μ _1,6-dmpzdo bridging ligands. The one-dimensional chain is constructed by the coordination of a μ _1,6-dmpzdo bridging ligand and Cu(II) ions. The data of the variable temperature (4–300 K) magnetic susceptibilities were fitted by using the one-dimensional chain fitting formula, which gave the magnetic coupling constants 2J = −98.88 cm⁻¹.     

Synthesis,crystal structure,and properties of a new lanthanide tartrate coordination polymer

A new coordination polymer of terbium tartrate [Tb(H₂O)₃(C₄H₅O₆)(C₄H₄O₆)] has been synthesized and crystallizes in the polar space group P4₁ with cell constants a = 6.0415(9), b = 6.0415(9), c = 36.516(7) Å, V = 1332.8(4) ų, Z = 4. The terbium(III) ion of title complex is nine-coordinate through oxygen donors. Four different coordination modes of tartrate occur. This Tb(III) complex exhibits a characteristic luminescence in the visible region upon excitation at 353 nm. The temperature-dependent magnetic properties of the Tb(III) complex were investigated in the temperature range of 2–300 K. Title compound exhibits significant ferroelectric properties at room temperature (remnant polarization 2P _r = 0.160 μC cm^?2, coercive field 2E _c = 44.5 kV cm^?1, saturation of the spontaneous polarization P _s = 0.176 μC cm^?2).     

Synthesis,crystal structures,and infrared spectroscopy of a series of lanthanide phosphonoacetate coordination polymers

Hydrothermal reactions of lanthanide chloride, phosphonoacetic acid (H₂O₃PCH₂COOH), and water in the presence of HCl provide a series of lanthanide coordination polymers. FT-IR spectra confirm that there are three kinds of structures among seven complexes, {[Ln₂(O₃PCH₂CO₂)₂(H₂O)₃]?·?H₂O}_∞ (type I) (Ln?=?La^III for 1; Pr^III for 2; Nd^III for 3 and Eu^III for 4), [Ln(O₃PCH₂CO₂)(H₂O)₂]_∞ (type II) (Ln?=?Tb^III for 5), and [Ln(O₃PCH₂CO₂)(H₂O)₂]_∞ (type III) (Ln?=?Ho^III for 6 and Yb^III for 7). Complexes 1–5 show 2-D 4,4,5,5-connected (4⁴?·?6²)(4⁵?·?6)(4⁶?·?6⁴)(4⁸?·?6²) topology networks and 2-D 4-connected (4⁴?·?6²) topology networks and then are further linked into 3-D supramolecular networks by hydrogen-bonding interactions; 6 and 7 both exhibit a 3-D 4-connected (4²?·?6³?·?8) topology with 1-D dumbbell-shaped channels. The results indicate infrared spectroscopy is in accord with the result of single-crystal X-ray analysis.     

Tetrathiafulvalene-based lanthanide coordination complexes: Synthesis,crystal structure,optical and electrochemical characterization

The explorative lanthanide coordination chemistry of 4′,5′-bis-(propylthio)tetrathiafulvenyl[i]dipyrido[3,2-a:2′,3′-c]phenazine (TTF-dppz) is described. Thereby, four new Ln(III) complexes, [Ln(NO₃)₃(TTF-dppz)₂] with Ln(III) = Nd (1), Eu (2), Gd (3), Tb (4), have been prepared and characterized. An X-ray crystallographic study of [Gd(NO₃)₃(TTF-dppz)₂] (3) shows that the Gd(III) ion is coordinated to six oxygen atoms from three bidentate nitrate ligands and four nitrogen atoms from two bidentate TTF-dppz molecules forming a distorted bicapped square antiprism coordination geometry. The UV-vis spectra of the four Ln(III) complexes show very strong absorption bands in the UV region consistent with ligand centred electronic π-π* transitions and an intense broad absorption band in the visible region corresponding to a spin-allowed electronic π-π* ¹ILCT transition from the TTF-dppz ligand. Upon coordination, the ¹ILCT band of the free TTF-dppz ligand is bathochromically shifted. The electrochemical studies reveal that all complexes undergo two reversible oxidation and one (quasi)reversible reduction processes, ascribed to the successive oxidations of the TTF moiety and the reduction of the dppz unit, respectively. Moreover, the magnetic properties of complexes 3 and 4 are discussed.     

Synthesis, crystal structure, and photochromism of novel two-dimensional supramolecular networks based on Keggin-type polyoxoanion and lanthanide coordination cations

Three new compounds [Ln(NMP)(4)(H(2)O)(4)][H(x)()GeMo(12)O(40)].2NMP.3H(2)O (Ln = Ce(IV) (1), Pr(IV) (2), x = 0; Ln = Nd(III) (3), x = 1; NMP = N-methyl-2-pyrrolidone) have been prepared in aqueous solution and characterized by elemental analyses, IR, UV-vis, and TG analyses. The single crystal X-ray diffraction shows that all three compounds are isostructural. In their structures, an interesting two-dimensional supramolecular network is constructed by the [GeMo(12)O(40)](4)(-) anion and [Ln(NMP)(4)(H(2)O)(4)](3+/4+) cation building blocks via hydrogen-bonding interactions, exhibiting the porous structure. Upon irradiation with UV light, the crystals of 1-3 show photochromic behavior.     

Synthesis and crystal structures of new lanthanide isonicotinates: coordination polymers and molecular complexes

New coordination polymers [Ce(C5H4NCOO)3(H2O)2] · 0.5C6H4N2 · 1.5H2O, [Ln(C5H4N-COO)3(H2O)2] (Ln = Ce, Pr) and [Ho(C5H4NCOO)2(H2O)4]NO3, and the tetranuclear complex [Ho4(OH)4(C5H4NCOO)6(H2O)8](NO3)2 · 3.5C6H4N2 · 5H2O were prepared by heating aqueous solutions of lanthanide(III) nitrates with 4-cyanopyridine under conditions of hydro-thermal synthesis. X-ray diffraction study demonstrated that the lanthanide atoms in the coordination polymers are bridged in chains through coordination to the carboxyl group of isonicotinic acid. The metal atoms in the tetranuclear complex are bound in pairs by six bidentate isonicotinate ligands.     

Hydrothermal synthesis and crystal structure of two new lanthanide coordination polymers with 1,2-phenylenediacetate

Two new compounds {[Ln₂(1,2-pda)₃(H₂O)₂]·?2H₂O} _n (1,2-H₂pda?=?1,2-phenylenediacetic acid, Ln?=?Tb, 1; Ho, 2) were prepared by hydrothermal reaction and characterized by X-ray crystallography. The Ln³⁺ is nine-coordinate by eight oxygen atoms of six 1,2-pda ligands and one oxygen of water. Ln³⁺ ions are bridged by 1,2-pda ligands via bridging/chelating-bridging pentadentate and chelating-bridging/chelating-bridging hexadentate coordination to form 3-D framework structures. Complex 1 emits strong green fluorescence corresponding to ⁵D₄???⁷F_j (j?=?6–3) transitions of the Tb³⁺.     

Synthesis,crystal structure and biological properties of Cd and Zn coordination polymers based on a flexible tripodal ligand

Two new coordination polymers, namely poly[[hexathiocyanatotetrakis{μ₃‐2,4,6‐trimethyl‐1,3,5‐tris[(triazol‐1‐yl)methyl]benzene}tricadmium(II)] 3.5‐hydrate], {[Cd₃(SCN)₆(C₁₈H₂₁N₉)₄]·3.5H₂O}_n ( 1 ), and poly[[hexathiocyanatotetrakis{μ₃‐2,4,6‐trimethyl‐1,3,5‐tris[(triazol‐1‐yl)methyl]benzene}trizinc(II)] 3.5‐hydrate], {[Zn₃(SCN)₆(C₁₈H₂₁N₉)₄]·3.5H₂O}_n ( 2 ), have been synthesized under hydrothermal conditions and characterized by elemental analysis, IR spectroscopy and single‐crystal X‐ray diffraction analysis. From the X‐ray analysis, it is noteworthy that polymers 1 and 2 are isostructural, with their three‐dimensional structures composed of three kinds of four‐connection metal ions and two kinds of three‐connection 2,4,6‐trimethyl‐1,3,5‐tris[(triazol‐1‐yl)methyl]benzene (TTTMB) ligand nodes. Each metal ion is six‐coordinated in a slightly distorted octahedral geometry. The antioxidant activity against DPPH (2,2‐diphenyl‐1‐picrylhydrazyl) and the antidiabetic activity against α‐amylase of the synthesized compounds were evaluated in vitro. The results of the DPPH free‐radical scavenging assay showed that polymers 1 and 2 exhibited strong antioxidant effects, with IC₅₀ values of 3.81 and 2.56 mg ml^?1, respectively. The IC₅₀ value in the antidiabetic studies of polymer 1 was 3.94 mg ml^?1, while polymer 2 exhibited no antidiabetic activity. Polymers 1 and 2 revealed different inhibitory activities on DPPH and α‐amylase, which indicated that the metal ions play important roles in the biological activity of coordination polymers. In addition, the solid‐state photoluminescence properties and thermal stability of 1 and 2 have been investigated.     

Four distinctive 1-D lanthanide carboxylate coordination polymers: Synthesis,crystal structures and spectral properties

Four novel lanthanide coordination polymers [Pr(mal)(OH)(bipy) · 2H₂O]_n (1), {[Dy¹(SBA)₃(H₂O)₂][Dy²(SBA)₃(H₂O)₂] · 4H₂O}_n (2), {[Tb(OHnic)(Onic)(H₂O)₅ · (OHnicH)] · H₂O}_n (3) and {[Sm(OHnic)(Onic)(H₂O)₅ · (OHnicH)] · H₂O}_n (4) (Hmal = maleic acid, HSBA = 4-sulfobenzoic acid, OHnicH = 6-hydroxynicotinic acid and bipy = 2,2′-bipyridine) have been synthesized and determined by single crystal X-ray diffraction. Complex 1 is a 1-D helical chain with seven-coordinated praseodymium centers. Complex 2 forms 1-D chain-like molecular structure containing two crystallographically unique dysprosium centers, the Dy¹ center is seven-coordinated while Dy² is eight-coordinated. The isomorphous complexes 3 and 4 exhibit an unprecedented 1-D chain-like polymeric structure through hydroxyl oxygen atoms of bridging Onic²⁻ anions linking up the neighboring central ions, and there exist three types of 6-OHnicH ligands in the structural unit which is rare for lanthanide carboxylate complexes. The photophysical properties of these complexes were studied using ultraviolet absorption spectra, fluorescence excitation and emission spectra.     

Synthesis,structures, luminescent and dielectric properties of lanthanide coordination polymers

Under hydrothermal conditions, four lanthanide coordination polymers were synthesized based on 4-(4,5-dicarboxy-1H-imidazol-2-yl)pyridine 1-oxide (H₃DCImPyO), with the molecular forumulas [Eu(HDCImPyO)·(H₂O)₂·(CHO₂)]_n (1), [Sm(HDCImPyO)·(H₂O)₂·(HCO₂)]_n (2), {[La(HDCImPyO)·(H₂O)·(HCO₂)]·O₂}_n (3) and {[Y(HDCImPyO)·(C₂O₄)·(H₂O)₂]·H₂O}_n (4). With diverse coordination modes, they were further characterized by elemental analysis, infrared spectroscopy, dielectric measurement, and single-crystal X-ray structural analysis. Complexes 1 and 2 were isostructural and had similar structures with {4⁴, 6²} topology. Complex 1 exhibited strong fluorescent emission in the solid state at room temperature. In 3, HDCImPyO^2? adopted μ₄-kO, O′: kO′, O′′: O′′′: O′′′′ coordination to bridge four La(III) ions to form a 3-D framework with {4. 5²}₂{4². 5¹⁰. 6¹². 7. 8³} topology. In 4, both HDCImPyO^2? ligands and Y³⁺ cations were simplified as linkers to form an interpenetrating 3-D framework with {4¹³. 6²}₂{4²². 6⁶} topology.     

Synthesis,crystal structure and magnetism of a three-dimensional Mn(II) coordination polymers with 2,5-dimethylpyrazine-1,4-dioxide as bridging ligand

A novel three-dimensional Mn(II) coordination polymer, {[Mn(μ_1,6-dmpzdo)₃]?·?(ClO₄)₂} _n , has been synthesized with 2,5-dimethylpyrazine-1,4-dioxide (dmpzdo) as a bridging ligand and its crystal structure determined by X-ray crystallography. The complex crystallizes in a trigonal system with a space group R-3 and a?=?11.6672(14), b?=?11.6672(14), c?=?16.652(4)?Å. In the complex each Mn(II) is coordinated by six μ_1,6-dmpzdo bridging ligands and each μ_1,6-dmpzdo bridging ligand coordinates two Mn(II) ions, forming a three-dimensional structure. The variable temperature (4–300?K) magnetic susceptibility data gave the magnetic coupling constant 2J?=??0.30?cm^?1.     

Syntheses,crystal structures,and magnetic and luminescent properties of a series of lanthanide coordination polymers with chelidamic acid ligand

A series of lanthanide(III) complexes with chelidamic acid ligand, [Ln(C₇H₂NO₅)·3H₂O]_n·nH₂O (Ln = La (1), Y (2), Sm (3), and Nd (4)), [Gd₂(C₇H₂NO₅)₃·4H₂O]_n·2nH₂O (5) and [Ce(C₇H₂NO₅)·1.5H₂O]_n (6), have been synthesized by hydrothermal method and structurally characterized by single-crystal X-ray diffraction. Complexes 1–4 are isostructural and possess 2D framework. Complex 5 contains two different Gd(III) ions linked through carboxylate group to form a 2D framework. Complex 6 exhibits a (4⁴) topology 2D network. The variable-temperature magnetic properties of 3 and 5 have been investigated. Furthermore, the photoluminescent properties of 1, 2, 3, and 5 at room temperature were also studied.     

几种三维镧系配位聚合物的合成、结构表征及其性质测定

在水热条件下合成了四个氨三乙酸配合物[Ln(NTA)(H2O)]n(Ln=Sm(III)、Gd(III)、Dy(III)和Er(III);NTA=氨三乙酸),分别标记为1、2、3和4;利用元素分析、红外光谱和X射线单晶衍射等对其进行了结构表征.结果表明,配合物1-4同晶同构,中心原子采取N1O7的配位模式形成扭曲的十二面体几何构型.配合物以菱形四面体Ln8C14O28为基本构筑块,通过O—C—O和氢键形成有序的三维结构.此外,四个配合物均存在镧系收缩效应;配合物1显示出反铁磁性,配合物2对Hg2+有良好的荧光选择性.     

Synthesis and crystal structures of two nickel coordination polymers generated from asymmetric malate ligand

Two nickel coordination polymers [Ni(H₂O)(C₄H₄O₅)]·H₂O 1 and [Ni(H₂O)(mal)(phen)] 2, have been hydrothermally synthesized and structurally characterized by single crystal X-ray diffraction. Crystal data for 1: C₄H₈O₇Ni, monoclinic Cc, , , , , Z=4. Crystal data for 2: C₁₆H₁₄N₂O₆Ni, orthorhombic Pna2₁, , , , Z=4. Compound 1 is constructed from [Ni(H₂O)(C₄H₄O₅)] sheets pillared through β-carboxylate groups into a 3D framework, which exhibits a diamond-like network. Compound 2 exhibits a 3D supramolecular network. To our knowledge, compound 1 represents the first diamond-like topology in the system of metal-malate. Other characterizations by elemental analysis, IR and TG are also described. The magnetic behavior of compound 1 has been studied.     

Synthesis, crystal structure, and luminescence properties of coordination polymers based on cadmium isonicotinates

Heating a solution of cadmium nitrate and isonicotinic acid in N,N′-dimethylformamide or dimethyl sulfoxide gave three new coordination polymers, [Cd(Inic)₂] · 0.5DMF (I), [Cd₃(DMSO)₆(Inic)₂(SO₄)₂] (II), and [{Cd(DMSO)(Inic)}₂(SO₄)] · 2H₂O (III), which were studied by X-ray crystallography. Compounds I and III were characterized by IR spectroscopy and elemental and thermogravimetric analyses and luminescence spectroscopy.