Sonochemical Synthesis and Characterization of the New Plate-Shaped Lead(II)–Iodo Coordination Polymer: A Precursor to Produce a Pure Phase Nano-Sized Lead(II) Oxide

Preparation of plate-shaped nanostructures of a new 1D polymeric lead(II) complex containing the Pb₂-(μ-I)₂ motif, [Pb(neo)I₂] _n ,(1) where neo is the abbreviation of neocuproine, using a sonochemical method is described. The new coordination polymer is characterized by scanning electron microscopy, X-ray diffraction (XRD), elemental analysis and infrared spectroscopy. The single crystalline material is obtained using a heat gradient applied to a solution of the reagents. Single-crystal XRD analysis indicates that a coordination number of six for Pb^II ions, (i.e., PbN₂I₄) with an asymmetrical coordination sphere and “stereo-chemically active” electron lone pairs. They also show that the chains interact with each other through π–π stacking interactions creating a 3D framework. PbO nanoparticles are obtained by thermolysis of 1 at 180?°C with oleic acid as a surfactant. Scanning electron microscopy confirms formation of PbO particles with a size of ~25?nm.     

A New Cyanide-Bridged CrIII–MnIII One-Dimensional Coordination Polymer with Pyridine Carboxamide Ligand

A new one-dimensional cyanide-bridged Cr^III–Mn^III complex [Cr(bpb)(CN)₂][Mn(bpb)]·2CH₃OH [bpb^2? = 1,2-bis(pyridine-2-carboxamido)benzenate] (1) has been synthesized by the reaction of [Mn(bpb)(H₂O)₂]ClO₄ and K[Cr(bpb)(CN)₂]. The single-crystal X-ray diffraction analysis shows that the structure of complex 1 is a one-dimensional coordination polymer type with two different metal centers which is alternated linked by cyanide group from the K[Cr(bpb)(CN)₂] building blocks. Magnetic investigations reveal that the magnetic interaction between Cr(III) and high-spin Mn(III) ions through the cyanide bridge is weak antiferromagnetic coupling.     

Synthesis and Characterization of New Cobalt(II)–Pyrazine Coordination Polymer as Precursor for Preparation of Co(II) Oxide Nanoparticles: Surprising Coordination,DFT Calculation and Spectroscopic Studies

The new 2-D cobalt(II) coordination polymer with pyrazine was synthesized surprisingly from reaction of CoCl₂ and tetrapyrido[3,2-a:2′,3′-c:3″,2″-h:2?,3?-j]phenazine (tpphz) in methanol as medium and characterized by means of Fourier transform infrared spectroscopy (FT-IR), UV–Vis spectroscopy and X-ray single crystal analysis. The results showed that coordination polymer consist of cobalt(II) chain with pyrazine-bridged which crystallizes in orthorhombic unit cell (a?=?10.1307, b?=?10.1310, c?=?10.6838 Å) and space group Pban. Density functional theory (DFT) calculations were also done to figure out the electronic structure of the compound from theoretical aspect. The electronic spectrum of coordination polymer was investigated and the DFT/TDDFT procedures were employed to assign the absorption bands. The thermal decomposition of the title compound resulted in formation of cobalt(II) oxide nanoparticles with average size of 50 nm.     

Ultrasound-Assisted Synthesis of a Novel Nano-Zigzag-Pattern Lead (II) Metal–Organic System: A New Precursor to Produce Nano-Sized PbO

A sonochemical method was used to synthesize a new nano Pb(II) 1D metal–organic zigzag chain [Pb(p-2-einh)NO₂]_n (1) (p-2-einh?=?(1-(pyridin-2-yl)ethylidene)isonicotinohydrazide). The compound was characterized by scanning electron microscopy (SEM), transmission electron microscopy, elemental analysis, IR spectroscopy, thermogravimetric analysis, X-ray powder diffraction, and single-crystal X-ray analysis. The X-ray analysis reveals a 1D zigzag-chain metal–organic polymer structure for 1 that is further extended to a 3D supramolecular structure by—interaction and other labile interactions. A coordination number of six was determined for the Pb(II) ions in PbN₃O₃. Lead oxide nanoparticles were prepared at 180?°C by thermolysis of 1. The average diameter of the nanoparticles was 20 nm. The size and morphology of the PbO samples were observed using SEM, and the structure of the system was optimized by DFT calculations. The calculated structural parameters and FT-IR spectra are consistent with the crystal structure.     

Syntheses and Characterization of New Nano-porous Soft Copper(II) Metal–organic Framework and Nano-porous Two-dimensional Manganese(II) and Zinc(II) Coordination Polymers with 4,4′-Bipyridine and 2-Sulfobenzoic Acid

Three new Cu(II), Mn(II), and Zn(II) coordination polymers with 4,4′-bipyridine (4,4′-bipy) and 2-sulfobenzoic acid (2-H₂sb) ligands, [M(4,4′-bipy)(2-sb)(H₂O)]_n, have been synthesized and characterized by IR spectroscopy and elemental analyses. The structures were determined by single-crystal X-ray crystallography. The structural studies show that the metal atoms have six-coordinate geometry with a distorted octahedral environment constructed with 4,4′-bipy and 2-sb²⁻ linkers stacked over each other to generate a two-dimension motif. Self-assembly of these compounds in the solid state is likely caused by coordination and hydrogen-bonds. While polymers containing Zn(II) and Mn(II) have analogous structures, the Cu(II)-containing nano-porous soft metal–organic framework presents a different structure.     

Mixed Solvothermal Synthesis of a New Heterometallic Coordination Polymer Containing Two Distinct Inorganic Cd–O–Ca Chains

A new heterometallic coordination polymer, namely [Cd₂Ca₂(PBDC)(H₂O)₂(e-urea)(DMF)]_n·2n(DMF) (1 H₂PBDC = terephthalic acid, DMF = N,N-dimethylformamide, e-urea = ethyleneurea) has been synthesized by combining the PBDC ligand with Cd(II) and Ca(II) salts under mixed solvothermal conditions. Single-crystal X-ray diffraction analysis reveals that 1 is an extended three-dimensional framework containing two distinct inorganic Cd–O–Ca chains, and can be simplified into a 4-connected topological network based on three unequivalent nodes. Luminescent study reveals that 1 exhibits strong, ligand-centred luminescence in the solid-state at room temperature.     

Hydrothermal Synthesis of a Nano-sized Mercury(II) N–N–O Donor Coordination Compound

A novel nano-structures mercury(II) coordination compound, [Hg (HPCIH) I₂] (1), (“HPCIH” is the abbreviation of 2-pyridinecarbaldehyde isonicotinoyl hydrazone) has been synthesized by a hydrothermal method that produces the coordination compound at nano size. The new nanostructure was characterized by transmission electron microscopy, scanning electron microscopy, X-ray powder diffraction elemental analysis and IR spectroscopy. Compound 1 was structurally characterized by single crystal X-ray diffraction and the single-crystal structure of this complex shows that each mercury(II) center is five coordinated with two N-donor and one O-donor atoms from “HPCIH” ligand and two iodo anions. Self-assembly of this complexes is realized by CH····I, I····I and π–π stacking interactions. The supramolecular features in these complexes are controlled by weak directional intermolecular interactions.     

3D Silver(I)–Diglycolate Coordination Polymer with Short Ag–Ag Bond

Abstract  

A new silver complex [Ag₂(dga)] 1, (dgaH₂ = Diglycolic acid) is synthesized and characterized by single crystal X-ray diffraction, IR, elemental analysis. The results showed that it is a monoclinic system with crystal parameters: a = 9.9372(11) ?, b = 5.5719(5) ?, c = 11.1973(12) ?, β = 93.044(10)° and Z = 4. A unique coordination mode of dga²⁻ ligand is observed in the title complex. Crystal structure analysis exposed the existence of two different Ag–Ag bonds with the distances of 2.83 and 3.27 ?. Room temperature photoluminescence study of the silver–dga complex shows emission in the blue region which may be assigned as metal centered (d-s/d-p) transitions. Thermal study has been performed.     

A Novel Co(II) Coordination Polymer Assembled from V-shaped 2,3,2’,3’-Thiodiphthalic Acid and N-donor Ancillary Ligand: Syntheses,Structure and Properties

A novel coordination polymer {[Co₂(tdpa)(bpe)_1.5(H₂O)]·(bpe)_0.5·(H₂O)} _n (1) has been hydrothermally synthesized through the reaction of 2,3,2’,3’-thiodiphthalic acid (H₄tdpa) with divalent cobalt salt in the presence of ancillary nitrogen ligand (bpe = trans-1,2-bis(4-pyridyl)ethene) and characterized by IR spectra, elemental analysis and single crystal X-ray diffraction. Due to various coordination modes and conformations of the versatile 2,3,2’,3’-thiodiphthalic acid ligand, the complex exhibits structural and dimensional novelty. In complex 1, metal–organic ribbons (Co-tdpa) are connected together through bpe ligands to generate a three-dimensional (3D) metal–organic framework. The structure of 1 can be described as a (3,6)-connected network with a Schläfli symbol of (4²·6)(4⁴·6¹⁰·8) topology. The thermal stability of the complex 1 was studied by thermal gravimetric analyses (TGA), and the UV?vis absorption property of complex 1 was also investigated.     

Copper(II) acetate-induced hydrolytic C–N bond cleavage of a topologically constrained tetraaza macrotricycle

A topologically constrained tetraaza macrotricycle, 2,2,4,10,10,12-hexamethyl-1,5,9,13-tetraazatricyclo[11.3.2.2^5.9]eicosane (L²), has been prepared by the reaction of 5,7,7,12,14,14-hexaazamethyl-1,4,8,11-tetraazacyclotetradecane (L¹) with 1,3-dibromopropane. Interestingly, L² reacts with Cu(OAc)₂ · H₂O to produce [CuL³]²⁺ (L³ = 2,2,4,10,10,12-hexamethyl-1,5,9,13-tetraazabicyclo[11.3.2]octadecane) as the only product under mild conditions, showing that the C–N bonds at one of the two N–CH₂CH₂–N linkages of the macrotricycle are readily broken in the presence of the metal salt. The complex [CuL³]²⁺ exhibits stronger ligand field strength than other related copper(II) complexes with a 5-6-6-6 chelate ring sequence and is unusually inert against decomposition in acid solutions.     

Structural Characterization of a Cu(I) Coordination Polymer Constructed by Weak Intermolecular Cu–Cl⋯Cl–Ar Interaction

The copper(I) complex [Cu(DPPEO)(L₁)Cl] · CH₃CN (1) (DPPEO = 1,2-bis(diphenylphosphino)ethane monoxide; L₁ = 5,7-dimethyl-2-chloronaphthyridine) was prepared by reacting L₁ with CuCl in the presence of DPPE. The compound has been characterized by X-ray diffraction analysis. Compound 1 is a tri-coordinated mononuclear complex, which forms one-dimensional chain through intermolecular halogen-halogen bonds.     

Novel Proton-Conducting Polymer Electrolytes Based on Poly(Vinylidene fluoride-co-hexafluoropropylene)–Ammonium Thiocyanate

The polymer electrolytes composed of poly(vinylidene fluoride-co-hexafluoropropylene) with various concentration of ammonium thiocyanate salt have been prepared by solution casting technique. The complex formation between polymer and dissociated salt has been confirmed by X-ray diffraction analysis and Fourier transform infrared spectroscopy. The highest conductivity has been found to be 6.5?×?10^?3?S?cm^?1 at 343?K for 25?wt% ammonium thiocyanate. The temperature-dependent conductivity of polymer electrolyte follows Arrhenius hopping relation. Thermogravimetric analysis has been used to ascertain the thermal stability of the polymer electrolytes. Atomic force microscopy analysis predicts the roughness parameter of the sample with higher conductivity.     

Hydrothermal Synthesis,Crystal Structure and Characterization of a Novel 3D Pillared-Layer 3d–4f Lanthanum-Copper Heterometallic Coordination Polymer

A novel three-dimensional (3D) pillared-layer 3d–4f lanthanum-copper heterometallic coordination polymer, {La₂Cu₇I₆(IN)₇(H₂O)₆·2H₂O} _n (1) (HIN = isonicotinic acid), has been synthesized by hydrothermal reaction of La₂O₃, CuI, HIN with HNO₃, and characterized by elemental analyses, IR, PXRD, and single-crystal X-ray diffraction. The structure determination reveals that the 3D framework of 1 is constructed upon [Cu₇I₆] _n ⁿ⁺ inorganic layers linked by dimeric La₂(IN)₆ pillars. Additionally, the thermogravimetric analysis and luminescent property of 1 were investigated and discussed.     

Structures and Properties of New Cadmium(II) and Copper(II) Metal–Organic Frameworks Based on Flexible Bridged 1,4-bi(1H-imidazol-1-yl)butane Ligand

Two new metal–organic frameworks (MOFs) based on cadmium(II) ions, 1,2-benzenedicarboxylic acid (BDC), flexible ligand 1,4-bi(1H-imidazol-1-yl)butane (BIIM), coordinated water molecules, [(BIIM)(BDC)(H₂O)Cd]_3n (1) and copper(II) ions, BIIM, coordinated water, free thiophene-2,5-dicarboxylate (TDC), free water, {[(BIIM)₄(H₂O)₄Cu₂]·(TDC)₂·(H₂O)₁₂}_n (2) are prepared and characterized by X-ray diffraction, thermal gravimetric analysis (TGA), infrared (IR) spectrum and the photoluminescence property for complex (1). The X-ray diffraction analysis reveals that the structures of complexes 1 and 2 are 2D structures through the C–H···π stacking interactions (for 1) and the BIIM bridging connections (for 2). The IR spectrum for 1 and 2 are presented in the paper, for 1, the strong peaks at 1399 and 1573 cm^?1 are owing to the carboxylic CO₂ ^? symmetry and asymmetry stretching vibrations of BDC. The features of the IR spectrum are consistent with the single crystal structures. The TGA reveal the water is the first lost material from complex, then the ligands removed, and finally the residues of these two complexes are the metal oxide.     

Electrochemical Synthesis of Cu (II) Coordination Polymer Coatings Based on 2,2′-Thiodiacetic Acid and 1,2,4,5-Benzenetetracarboxylate

Electrochemical synthesis of coordination polymers of Cu(II), [Cu(TDA)]_n and [Cu₂(BTC)(H₂O)₆?6H₂O]_n in which H₂TDA is 2,2′-thiodiacetic acid and BTC stands for 1,2,4,5-benzenetetracarboxylate was carried out by the electrochemical oxidation of Cu anode in the presence of H₂TDA (a flexible ligand), and 1,2,4,5-benzentetracarboxylic acid (H₄BTC) (a rigid ligand) in aqueous solutions. The structure of coordination polymers were characterized by scanning electron microscopy, X-ray powder diffraction, elemental analysis, thermal gravimetric and differential thermal analyses. The crystal structure of the compounds consists of one-dimensional cubical crystal polymeric units of [Cu(TDA)]_n and [Cu₂(BTC)(H₂O)₆?6H₂O]_n. Furthermore, the coordination number of Cu (II) ions in synthesized coordination polymers to be found five. The main advantages of electrosynthesis are the minor synthesis time, the milder conditions and the facile synthesis of coordination polymer coatings.     

An Organic–Inorganic Hybrid Polymer Based on Molybdenum(V) Phosphate and Cadmium(II) Complex

An unusual organic–inorganic hybrid polymer, [Cd(pztt)(H₂O)₂]₄[CdMo ₁₂ ^V O₂₄(OH)₆ (HPO₄)₄(H₂PO₄)₂(PO₄)₂]·10H₂O (pztt = 3-(pyrazin-2-yl)-5-(1H-1,2,4-triazol-3-yl)-1,2,4-triazliyi) (1), have been hydrothermally synthesized and structurally characterized by the elemental analysis, TG, IR, UV–Vis, PXRD and the single-crystal X-ray diffraction. In compound 1, the sandwich-type {Cd[Mo₆P₄O₃₁]₂} units are modified with Cd(pztt)(H₂O)₂ fragments to lead bi-supported dimer clusters, which are further linked by binuclear complex subunits [Cd₂(pztt)₂(H₂O)₄] to yield unusual 1-D chains. The 1-D chains are further packed into 2-D and 3-D supramolecular assemblies via strong hydrogen-bonding interactions. In addition, the electrochemical behavior of 1-CPE and the photoluminescence properties of 1 in the solid state at room temperature have been investigated in detail.