Synthesis,Crystal Structures,Luminescence, Biological and Catalytic Properties of Two d10 Metal-Organic Coordination Polymers Constructed from Mixed Ligands

Two d¹⁰ metal-organic coordination polymers, [Cd₂(4-cpa)₄(bmip)₂]_n (1) and [Zn(4-cpa)₂(4,4′-bpy)]_n (2), [4-cpa = 4-chlorophenylacetate, bmip = 1,3-bis(2-methylimidazoly)propane, 4,4′-bpy = 4,4′-bipyridine], were hydrothermally synthesized and characterized by IR spectroscopy, elemental analysis, thermogravimetric analysis (TGA), powder X-ray diffraction and single-crystal X-ray diffraction. Single-crystal X-ray diffraction studies indicated that both 1 and 2 display analogous wave-like infinite chain structures. The two coordination polymers are further extended into 3D supramolecular structures through π···π stacking interactions and C–H···O hydrogen bonds for 1 and π···π stacking interactions, C–H···π stacking interactions and C–H···O hydrogen bonds for 2. Both 1 and 2 emit the intense blue luminescence at room temperature. The 4-Hcpa ligand and complexes 1 and 2 have been screened for their herbicidal activities against Brassica napus L. and Echinochloa crusgalli L. The results are compared with the activity of quizalofop-P-ethyl. Both compounds exhibit high catalytic properties on degradation of methyl orange in Fenton-like process.     

Synthesis, Crystal Structures and Fluorescence Properties of Two One-Dimensional Cadmium(II) Coordination Polymers Containing Flexible Bis(benzimidazole) Ligands

Two one-dimensional Cd(II) coordination polymers constructed by ribbon-like molecules, {[Cd(L₁)₂(NO₃)]·NO₃} _n (1) (L₁ = 1,3-bis(5,6-dimethylbenzimidazol-1-yl)benzene) and [Cd(L₂)₂(NO₃)₂] _n (2) (L₂ = 1,3-bis(benzimidazol-1-yl)benzene) have been obtained through assembly of the two structurally similar flexible bis(benzimidazole)-based ligands and cadmium nitrate tetrahydrate. The cadmium(II) centers display different coordination environments with trigonal-bipyramidal geometry in 1, and a octahedral geometry in 2. Weak C–H···O interactions in 1 result in a two-dimensional supramolecular layer; two π–π interactions are present in 2 forming a three-dimensional supramolecular network structure. The solid state fluorescence properties of 1 and 2 were investigated.     

Two New Zn(II) Coordination Polymers Constructed from Asymmetric Biphenyl-Dicarboxylate and Imidazole-Containing Ligands: Structures and Photoluminescent Properties

Two new coordination polymers, [Zn(2,4′-bpdc) (L₁)_0.5·(H₂O)] _n (1) and {[Zn(3,4′-bpdc) (L₁)]·(H₂O)} _n (2), have been obtained from hydrothermal reactions of zinc (II) nitrate with the ligands 1,4-bis(imidazol-1-yl)benzene (L) and two asymmetric biphenyl-dicarboxylate [biphenyl-2,4′-dicarboxylate (2,4′-bpdc) and biphenyl-3,4′-dicarboxylate (3,4′-bpdc)]. Single-crystal X-ray diffraction analysis the two coordination polymer show different structures due to the different dicarboxylate ligands. Complex 1 features a 3D mab topological net. Complex 2 is unusual case that has 3D frameworks constructed from 2D 4⁴-sql layers by parallel polycatenation. The photoluminescent properties of 1 and 2 have also been investigated.     

Two 3D Supramolecular Coordination Polymers Constructed from Aromatic Carboxylic Acids and Flexible Bis(thiabendazole) Ligands

Two coordination polymers (CPs), [Zn(L1)(H₂bta)] (1) and [Co(L2)(ndc)]·0.75H₂O (2), (L1?=?1,6-(thiabendazole)hexane), L2?=?1,3-(thiabendazole)propane, H₄bta?=?1,2,4,5-benzenetetracarboxylic acid, H₂ndc?=?2,6-naphthalenedicarboxylic acid) have been hydrothermally synthesized and characterized. Single crystal X-ray diffraction analyses reveal that CP 1 and CP 2 feature 1D infinite zigzag and “Ω”-like chains, and further extend into 3D supramolecular framework by O–H?O and C–H?O hydrogen bonding interactions, respectively. Furthermore, the luminescence properties, thermal stability, and catalytic degradation of methyl orange in a Fenton-like process are also investigated in detail.     

Hydrothermal Synthesis, Crystal Structures and Photoluminescent Properties of Two New Co(II) Coordination Polymers Derived from Dicarboxylate and N-Donor Ligands

Two new Co(II) coordination polymers with 5-position substituted 1,3-benzenedicarboxylate and N-donor auxiliary ligands, [Co(5-OH-ip)(L₁)_1.5(H₂O)]_n (1) and [Co(5-NO₂-ip)(L₂)_1.5]_n (2) (5-OH-ip = 5-hydroxyisophthalic acid, 5-NO₂-ip = nitroisophthalic acid, L₁ = 1,4-bis(imidazol-1-yl) benzene and L₂ = 1,4-bis(1-imidazol-yl)-2,5-dimethyl benzene), were synthesized by hydrothermal reactions. Complex 1 shows a 3-fold interpenetrating 3D framework with the topological symbol of (4⁴·6⁶). Complex 2 exhibits a 3D framework with the vertex symbol of (4²·6⁸). Furthermore the luminescent properties of 1 and 2 were investigated.     

Supramolecular Architectures in Three Metal(II) Coordination Polymers with 2,5-Dichloroterephthalate and Flexible Bis(Benzimidazole) Ligands

Three supramolecular coordination polymers, namely [Ni(L1)(DCTP)(H₂O)] _n (1), [Cu(L2)(DCTP)] _n (2), [Co(L3)(DCTP)] _n (3) (L1?=?1,5-bis(5,6-dimethylbenzimidazole)pentane, L2?=?1,4-bis(5,6-dimethylbenzimidazole)butane, L3?=?1,4-bis(benzimidazole)-2-butylene) have been hydrothermally synthesized and characterized by single crystal X-ray structure determination, FT-IR, elemental analysis, X-ray powder diffraction (XPD), and thermogravimetric analysis (TGA). CP 1 exhibits 2D 6³ honeycombed network structure, which is further extended into a 3D Moganite (mog) supramolecular framework by classical O–H?O hydrogen-bonding interaction. CPs 2 –3 present 2D (4,4) layers, and 3D supramolecular frameworks that are formed by π–π stacking interactions. Furthermore, the catalytic activities of CPs 1–3 for the degradation of methyl orange in a Fenton-like process has been investigated, and CPs 1–3 show strong photoluminescence properties at room temperature in solid state.     

Two Energetic Cobalt(II) Coordination Polymers Derived from Isomeric Ligands

Isomer is sometimes fundamental to the formation of the resulting compounds. The design and preparation of coordination compounds based on isomers is of tremendous paramount since they have a lot in common but simultaneously some difference, which can lead to variation of both the topologies and properties. Solvothermal reactions of Hn-pytza (n = 3, 4) with Co(ClO₄)₂·6H₂O, afforded two interesting coordination polymers, one dimensional [Co(3-pytza)₂(H₂O)₂]_n·2nH₂O (1) and three dimensional [Co(4-pytza)₂]_n (2), where Hn-pytza = 5-(n-pyridyl)tetrazole-2-acetic acid (n = 3, 4). The thermal decomposition behavior of the two compounds were characterized by the differential scanning calorimetry (DSC) and thermogravimetric-differential thermogravimetric (TG-DTG), showing [Co(4-pytza)₂]_n is superior to [Co(3-pytza)₂(H₂O)₂]_n·2nH₂O in terms of energetic performance. Furthermore, the entropy of activation (?S), enthalpy of activation (?H), and free energy of activation (?G) were calculated, as well.     

Synthesis, Crystal Structures and Luminescent Properties of pH-Dependent Zn (II) Coordination Polymers

Two new coordination polymers [Zn(L)(bib)] _n (1) and [Zn(L)(bib)_0.5] _n (2) [L = 5-hydroxyisophthalic acid and bib = 1,4-bis(2-methyl-imidazol-1-yl)butane] have been synthesized and characterized. X-ray single crystal diffractions show that complex 1 is a 2D layered structure and complex 2 is a 3D 6-connected topological net. Complex 1 are further assembled into a 3D supramolecular structure by intermolecular hydrogen bonding. Complex 2 features a two-fold interpenetrated pcu topology. Moreover, the fluorescent properties of complexes 1 and 2 were studied in the solid state at room temperature.     

Syntheses and Characterization of Three Coordination Polymers of Zinc(II) and Cadmium(II) with Dicarboxylates and Bis(thiabendazole) Ligands

Three d ¹⁰ coordination polymers formulated as [Zn(L1)₂(mip)] _n (1), [Zn(L1)(2,6-ndc)] _n (2) and [Cd(L2)_0.5(bpdc)] _n (3) (L1 = 1,1′-(1,3-propanediyl)bis(thiabendazole), L2 = 1,1′-(1,6-hexanediyl)bis(thiabendazole), H₂mip = 5-methylisophthalic acid, 2,6-H₂ndc = 2,6-naphthalenedicarboxylic acid, H₂bpdc = 4,4′-biphenyldicarboxylic acid) were hydrothermally synthesized. Complexes 1–3 were characterized by elemental analysis, IR spectroscopy, X-ray powder diffraction analysis, and single crystal X-ray diffraction. Complexes 1 and 2 present different chain structures, both of them are extended into 2D supramolecular architectures via C–H···O hydrogen bonds, while 3 is a three-fold interpenetrating three-dimensional framework with binodal 4,4-connected mog topology. The thermal stability, UV–visible spectroscopy and luminescence properties of complexes 1–3 were also examined. Furthermore, complex 3 exhibits relatively positive catalytic activity towards the degradation of methyl orange in a Fenton-like process.     

Imidazole-Containing Ligands Assisted Self Assembly of Two New Cd(II) Coordination Polymers: Syntheses, Crystal Structures and Photoluminescent Properties

Two new coordination polymers, {[Cd₂(PDC)₂(H₂O)₂(L₁)]·2H₂O}_n (1) and {[Cd (2,5-PDC)(H₂O)(L₂)]·H₂O}_n (2), have been obtained from hydrothermal reactions of Cd²⁺ ion with the 2,5-pyridinedicarboxylic acid (H₂PDC) and two imidazole-containing ligands [L₁ = 1,4-bis(imidazol-1-yl)benzene and L₂ = 1,4-bis(1-imidazol-yl)-2,5-dimethylbenzene]. Complex 1 features a three-dimensional 6-connected rob topological net. Complex 2 shows a two-dimensional 6-connected hxl topological net. The structural differences between 1 and 2 demonstrate that the different imidazole-containing ligands play critical roles in the formation of the resulting frameworks. The photoluminescent properties of 1 and 2 have also been investigated.     

Syntheses, Structures, and Luminescent Properties of Two Novel Coordination Polymers with Mixed Ligands

Two novel metal–organic coordination polymers {[Pb₂(MIP)₂(BDC)₂]·H₂O} _n 1 and [Cd(MIP)(NDC)] _n 2 [MIP = 2-(3-methoxyphenyl)-1H-imidazo [4,5-f] [1, 10] phenanthroline, BDC = terephthalic acid, NDC = naphthalene-1,4-dicarboxylic acid] were obtained from hydrothermal reaction and characterized by elemental analysis, thermogravimetric (TG) analysis, infrared spectrum (IR) and single-crystal X-ray diffraction. The coordination polymers crystallize in triclinic, space group P-1 with a = 1.0335(2), b = 1.4224(3), c = 1.8156(4) nm, β = 106.088(3)° for complex 1 and the complex 2 crystallizes in monoclinic, space group P2(1)/n with a = 1.2562(8), b = 1.4800(9), c = 1.3723(8) nm, β = 97.257(1)°, respectively. The metal ions Pb(II) are located in [:PbN2O4] pentagonal bipyramidal geometry in complex 1. The metal ions Cd(II) in complex 2 act as distorted octahedral geometry, being surrounded by four carboxylate oxygen atoms from three NDC ligands and two donor nitrogen atoms from one MIP molecule. Moreover, there are hydrogen bonds in the two complexes, and it is noteworthy that the existence of hydrogen bonds and π–π interactions reinforce the structural stability of the title complexes, which have been proved by TG analysis. The luminescent properties for the ligand MIP, NDC and complex 2 are also discussed in detail.     

Synthesis,Crystal Structures and Fluorescent Properties of Two Bimetallic Coordination Polymers

Two novel 2D and 3D bimetallic Cd^IINi^II coordination polymers, Cd(2Mpz)(H₂O)Ni(CN)₄ (I) (2Mpz: 2-methylpyrazine) and Cd(2Epz)(H₂O)Ni(CN)₄ (II) (2Epz: 2-ethylpyrazine), have been synthesized and characterized by elemental analysis, powder X-ray diffraction, IR spectra, fluorescent spectra, single crystal X-ray diffraction and thermogravimetric analysis. Based on the analysis of structures, it can be found that the Cd(II) ions in the two complexes have the similar octahedral coordination geometry of CdN₅O, which are linked by [Ni(CN)₄]²⁻ units at the equatorial plane to form 2D sheet layers [CdNi(CN)₄] _n . However, it’s noted that the coordination environment of Ni(II) ions and action of ligands are different. All the Ni(II) ions in I are the five-coordinated pentahedron configuration and 2-methylpyrazine acts as a bridging ligand linking the Cd(II) and Ni(II) ions of the adjacent layers, leading to the 3D metal–organic framework. The structure of II indicates all the Ni(II) ions are the four-coordinated square plane and 2-ethylpyrazine is a terminal ligand coordinated to Cd(II) ions, forming the 2D layer structure. Moreover, the two complexes display significant thermal stability and fluorescent properties.     

Hydrothermal Synthesis, Crystal Structures and Fluorescent Properties of Two New d10 Metal Coordination Polymers with Two Mixed Flexible Ligands

Two complexes, [Zn(qda)(bpp)] _n (1) and {[Cd(qda)(bpp)₂]·2H₂O} _n (2), (H₂qda?=?hydroquinone-O,O′-diacetic acid, bpp?=?1,3-bis(4-pyridyl)propane), were hydrothermally synthesized and characterized by single crystal X-ray diffraction analysis, FTIR and elemental analysis. Both compounds exhibit two-dimensional structures. The qda anions in compound 1 adopt two different trans conformations, coordinating to Zn²⁺ ions in a monodentate fashion, while in compound 2 they adopt only one trans conformation yet keeping the same coordination fashion as in compound 1. The bpp molecules show same anti-gauche coordination conformation in both 1 and 2. In addition, photoluminescence for 1 and 2 has been investigated in the solid state at room temperature.     

Syntheses, Structures, and Luminescent Properties of Two Novel Coordination Polymers with Poly-Carboxylate and N-Heterocyclic Ligands

Two novel metal–organic coordination polymers {[Pb(CIPT)(1,4-BDC)]·2H₂O} _n 1 and {[Zn₂(IPDT)₂(1,4-BDC)₂(H₂O)].3H₂O} _n 2 [CIPT = 2-(3-chlorophenyl)-1H-imidazo[4,5-f][1,10]phenanthroline, 1,4-BDC = terephthalic acid, IPDT = 4-(1H-imidazo[4,5-f][1,10]phenanthroline-2-yl)-2,6-dimethoxyphenol] were obtained from hydrothermal reaction and characterized by elemental analysis, thermogravimetric (TG) analysis, IR and single-crystal X-ray diffraction. Both of the two coordination polymers exhibit one-dimensional (1D) infinite chain structures through non-covalent interactions, and the existence of hydrogen bonds interactions lead the 1D chain to 2D layer structures. It is noteworthy that the existence of hydrogen bonds reinforces the structural stability of the complexes 1 and 2, which can be proved by TG analysis. The photoluminescent study of coordination polymer 1 shows that it exhibits fluorescent emission band at 637 nm, which is red-shifted by 46 nm relative to the free ligand CIPT.     

Self-Assembly of Polymers through Dynamic Coordination Chemistry and Hydrogen Bonding: Polymers from Mercury(II) Halides and Bis(amidopyridine) Ligands

The synthesis of hybrid organic–inorganic polymers by combination of mercury(II) halides with the ligand 1,5-bis(isonicotinamido)naphthalene, C₁₀H₆(NHCO-4-C₅H₄N)₂, 1. The compounds of formula [HgX₂(1)] form either linear (X = Cl, Br) or zig-zag (X = I) polymers and contain tetrahedral mercury(II) centers with bridging ligands 1. The polymers are further assembled by hydrogen bonding between amide groups. When X = Cl or Br, two-dimensional sheet structures are formed whereas, when X = I, a three-dimensional network is formed. A new polymeric form of [HgCl₂(Me₂SO)] is also described. Dedicated to Ian Manners for his pioneering research on organometallic polymers