Synthesis and Characterization of ZnS and ZnO Nanoparticles via Thermal Decomposition of Two New Synthesized One-Dimensional Coordination Polymers at Two Different Temperatures

Two new Zn(II) coordination polymers from ligand 2,5-bis(3-pyridyl)-3,4-diaza-2,4-hexadiene (bpdh) with different anions, [Zn(μ-bpdh)₂(NCS)₂]_n (1) and [Zn(μ-bpdh)₂(N₃)₂]_n (2) were synthesized and characterized by IR spectroscopy, elemental analyses and X-ray crystallography. The structures of the 1 and 2 may be considered coordination polymers of zinc(II) consisting of metallocyclic chains formed by bridging bpdh ligands, making a one-dimensional array of Zn^II and bpdh in a 1:2 stoichiometry. Different morphologies of ZnS and ZnO nano-particles were obtained by thermolyses of compounds 1–2 in oleic acid at different temperatures under air atmosphere, respectively. The ZnS and ZnO nanoparticles were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM).     

Synthesis and Characterization of a New Nano Lead(II) Two-dimensional Coordination Polymer by Sonochemical Method: A Precursor to Produce Pure Phase Nano-sized Lead(II) Oxide

A new nano-sized lead(II) coordination polymer, {[Pb₂(μ-3-bpdh)(μ-NO₃)₃(NO₃)]_n (1); (3-bpdh = 2,5-bis(3-pyridyl)-3,4-diaza-2,4-hexadiene)}, was synthesized by a sonochemical method. The structure of 1, which may be considered coordination polymer of lead(II), consists of metallocyclic chains formed by bridging NO₃ ⁻ and 3-bpdh ligands, thereby making a 2D array of Pb(NO₃)₂ and 3-bpdh. The thermal stability of compound was studied by thermogravimetric and differential thermal analyses. The new nano-structure coordination polymer was characterized by powder X-ray diffraction, elemental analysis and IR spectroscopy. The scanning electron microscopy shows the particle size of the 1 prepared by the sonochemical method is about 95 nm. The PbO nanoparticles were obtained by thermolysis of 1 at 180 °C with oleic acid as a surfactant. The scanning electron microscopy shows that the size of the PbO particles are ~60 nm.     

Preparation of Zinc(II) Oxide Nanoparticles from a New Nano-Size Coordination Polymer Constructed from a Polypyridyl Amidic Ligand; Spectroscopic, Photoluminescence and Thermal Analysis Studies

A new zinc(II) coordination polymer, {[Zn(bpcdp)₂(DMF)₄](ClO₄)₂·(H₂O)₂}_n (1) bpcdp = 2,6-bis(4-pyridinecarboxamide)pyridine has been synthesized and characterized by IR, ¹HNMR and ¹³CNMR spectroscopy. The single crystal X-ray data of compound 1 shows the zinc(II) atom has been considered as octahedral with ZnN₂O₄ coordination sphere. Two nitrogen atoms of bpcdp ligand and four oxygen atoms of DMF molecules have occupied coordination sphere around zinc(II) atoms. The prepared zinc(II) coordination polymer grows in three-dimensional network by hydrogen bonding and π–π stacking interaction. The nanostructure of compound 1 were obtained by sonochemical process and studied by scanning electron microscopy (SEM), X-ray powder diffraction (XRD), IR and NMR spectroscopy. Thermal stabilities of single crystalline and nano-size samples of compound 1 were studied by thermal gravimetric (TG) and differential thermal analyses (DTA). The ZnO nanoparticles were obtained by direct calcination of compound 1 at 400 °C and by thermolysis in oleic acid at 200 °C. The obtained zinc(II) oxide nanoparticles were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM).     

Cooperative Effect of 3,3′,4,4′-Benzophenonetetracarboxylic Acid and 1,10-Phenanthroline under Solvothermal Conditions to Afford Two Novel Zinc(II) and Cadmium(II) Complexes

Rational self-assembly of a flexible ligand 3,3′,4,4′-benzophenonetetracarboxylic acid and d¹⁰ transition metal salts in the presence of rigid bidentate ligand 1,10-phenanthroline yields two novel helical coordination polymers with different structural motifs; i.e., [Zn(H₂bbtc)(phen)₂ · 2H₂O] _n (1) and [Cd₂(bbtc)(phen)₄ · 2.25H₂O] _n (2) (H₄bbtc = 3,3′,4,4′-benzophenonetetracarboxylic acid, phen = 1,10-phenanthroline), under solvothermal condition. One is hydrogen bonded and π–π stacked together into a network, and the other is a covalently coordinated 3D framework. The coordination polymers were characterized by FT-IR, UV/VIS and fluorescent spectroscopy, single crystal X-ray diffraction, elemental analysis and differential thermal analysis/thermogravimetry (DTA/TG). The most intriguing structural feature is that each complex exhibits novel helical-spaced chains by reason of two different ligands coordinating to the metal centers. Additionally, compounds 1 and 2 showed good fluorescence properties compared to the free ligands.     

New Binuclear Complexes with Mixed Ligands and μ<Subscript>2</Subscript>-Phenol Oxygen Bridges: Synthesis Crystal Structures and Magnetism

Two new complexes, [M₂(L)₂(bpy)₂](ClO₄)₂ [L = methyl salicylate, bpy = 2,2′-bipyridine, M = Cu (1) and Zn (2)] have been synthesized and structurally characterized by X-ray structure analyses. The centrosymmetric dimeric structure consists of a binuclear unit, in which M (M = Cu or Zn) atoms are bridged by two phenol oxygen atoms as a μ ₂-bridged. The neighboring binuclear units interact with each other by two kinds of weak contacts: one kind is π–π stacking by π–σ attraction with an edge-to-face C–H···π interaction, and the second type is a H-bonding interaction, which extends the binuclear unit into a 3D network. Magnetic measurements confirm that 1 presents a very strong intradinuclear ferromagnetic coupling between the copper(II) ions.     

Structural and Magnetic Properties of One-Dimensional Squarate Bridged Coordination Polymers Containing 2-Aminomethylpyridine Ligand

Three novel one-dimensional (1D) coordination polymers with general formula {[M(μ-sq)₂(amp)₂]·H₂O}_n [M=Cu(II) (1), Zn(II) (2)] and [Cd(μ-sq)₂(amp)₂]_n (3) [sq: Squarate; amp:2-aminomethylpyridine] have been prepared and spectroscopically studied. Each metal (II) ion in 1–3 is octahedrally coordinated by two sq and two amp ligands. The amp ligands are N,N′ coordinated, while the sq ligands bridge the metal centers forming 1D linear chain structure. The individual chains are linked by O–H···O hydrogen bonds involving the hydrogens of water molecules (1–2), amino hydrogens and squarate O atoms (1–3). The hydrogen bonded layers are further assembled into three-dimensional supramolecular networks by weak aromatic π–π interactions. EPR results indicate that the ground state of the paramagnetic electron in 1 and Cu²⁺ doped complexes 2–3 is d_{x² - y²} d_{{x^{2} - y^{2} }} . Magnetic measurements reveal that complex 1 shows paramagnetic behavior.     

One-Dimensional Cobalt(II) and Zinc(II) Succinato Coordination Polymers with Nicotinamide: Synthesis, Structural, Spectroscopic, Fluorescent and Thermal Properties

Cobalt(II) and zinc(II) succinato (suc) coordination polymers with nicotinamide (nia), {[Co(μ-suc)(H₂O)₂(nia)₂] · 2H₂O} _n (1) and {[Zn(μ-suc)(H₂O)₂(nia)₂] · 2H₂O} _n (2) have been synthesized and characterized by elemental analyses, magnetic moments, IR and TG-DTA. Single-crystal X-ray analyses of 1 and 2 reveal that these complexes are isostructural and crystallize in triclinic space group Complexes 1 and 2 are 1-D coordination polymers, in which the metal(II) ions exhibit an octahedral geometry with two suc, two nia and two aqua ligands. The nia ligand is N-bonded, while the suc ligand bridges the metal centers through the carboxylate groups. The 1D chains are further assembled to form 3D networks by strong N–H···O and OW–H···O hydrogen bonds. IR spectra confirm the coordination modes of both suc and nia ligands, while TG-DTA data are in agreement with the crystal structures. Fluorescent analysis in the solid state shows that all complexes display intraligand (π–π*) emissions of nia.     

Synthesis, Crystal Structures and Thermal Stabilities of Lanthanide Coordination Polymers with 5-Nitroisophthalate

Two new lanthanide coordination polymers, namely, [Ho(ox)_0.5(nip)(H₂O)₃]·2H₂O (1) and [Gd(nip)(Hnip)(phen)] (2) (nip = 5-nitroisophthalate, ox = oxalate and phen = 1,10-phenanthroline) were synthesized under hydrothermal conditions. They crystallize in triclinic, P−1 space group and exhibit 1D structure features: complex 1 possesses a 1D parallel ladder structure bridged by oxalate and nip anions and compound 2 has 1D loop-like chain structure. Moreover, intermolecular attractions such as H-bonds and π–π stacking result in the high-dimensional supramolecular frameworks. The different coordination modes of the nip anions, the appropriate choice of multidentate bridging ligands and the intermolecular forces affect the topological structures. In addition, the thermal behavior of the complexes is investigated in air.     

Preparation of Cadmium(II) Oxide Nanoparticles from a New One-Dimensional Cadmium(II) Coordination Polymer Precursor; Spectroscopic and Thermal Analysis Studies

A one-dimensional Cd(II) coordination polymer containing 2-pyridinecarboxylate (2-pyc⁻) and iodide anions [Cd(μ-2-pyc)(μ-I)] _n (1), is synthesized and characterized by elemental analysis, IR spectroscopy, thermal analysis and X-ray crystallography. The single-crystal X-ray data show that the coordination number for the Cd²⁺ ion is five. The thermal stability of 1 was studied by thermogravimetry and differential thermal analyzes. Cd(II)O nanoparticles were prepared by direct calcination of 1 at different temperatures. The Cd(II)O nanoparticles were characterized by X-ray powder diffraction and scanning electron microscopy. The results show that the morphology of the Cd(II)O nanoparticles is dependent upon the thermolysis temperature.     

Synthesis and Characterization of Zinc(II) Oxide Nanoparticles by Thermal Decomposition of Two Zinc(II) Nitrite Coordination Polymer Precursors

Two zinc(II) coordination polymers, {[Zn(3-bpdb)(NO₂)]·0.5H₂O} _n (1) and [Zn(4-bpdb)(NO₂)₂] _n (2), 3-bpdb = 1,4-bis(3-pyridyl)-2,3-diaza-1,3-butadiene and 4-bpdb = 1,4-bis(4-pyridyl)-2,3-diaza-1,3-butadiene}, have been synthesized and characterized by elemental analyses and IR spectroscopy. Nanoparticles of zinc(II) oxide have been prepared by thermolyses of two different zinc(II) coordination polymers, 1–2. The nano-materials were characterized by scanning electron microscopy, X-ray powder diffraction and IR spectroscopy. The thermal stability of ZnO nano-particles was studied by thermal gravimetric and differential thermal analysis and showed that there is no loss of weight, which indicates that the products were zinc(II) oxide. This study demonstrates the coordination polymers may be suitable precursors for the preparation of nanoscale materials.     

Hydrothermal Synthesis of Metal–Organic Coordination Polymers Constructed from Asymmetric Semi-rigid V-shaped Dicarboxylate and Nitrogen-Contained Mixed Ligands

Three new coordination polymers, [Ni(2,4′-oba)(1,10-phen)] _n (1), {[Ni (2,4′-Hoba)₂(4,4′-bipy)(H₂O)₂]·2H₂O} _n (2) and [Zn(2,4′-oba) (4,4′-bipy)] _n (3) (2,4′-H₂oba = 2-(4-carboxyphenoxy)benzoic acid, 1,10- phen = 1,10-phenanthroline, and 4,4′-bipy = 4,4′-bipyridine) have been obtained by hydrothermal synthesis. The framework structures of these polymeric complexes have been determined by single-crystal X-ray diffraction studies. Complex 1 exhibits double-helical chains formed by π–π stacking interactions from the phenyl rings of the 1,10-phen ligands. Complex 2 forms a two-dimensional supramolecular architecture directed by hydrogen bonding. Complex 3 exhibits a three-dimensional structure; Schl?fli symbol of {4⁴·6¹⁰·8}. The luminescent property of compound 3 is discussed.     

Zinc(II) Metal–Organic Framework with Nano-Sized Channels Based on Paddle-Wheel Units

A Zn(II) metal–organic framework with nano-sized channels from 4,4′-bipyridine (4,4′-bipy) and 4′-sulfo-biphenyl-4-carboxylate (sbpc²⁻) ligands, {[Zn(μ-4,4′-bipy)_1.5(μ-sbpc)]·5H₂O} _n (1), has been synthesized by the hydrothermal method. Compound 1 was characterized by X-ray powder diffraction, IR spectroscopy, elemental analysis and single-crystal X-ray crystallography. The structural studies show the Zn atoms have a six-coordinate geometry with a distorted octahedral environment constructed of paddle-wheel [Zn₂(OOC)₄] building units with 4,4′-bipy and sbpc²⁻ linkers stacked over each other to generate three-dimensional nano-sized channels occupied by guest H₂O molecules.     

A New Metal–Organic ZnII Supramolecular Assembled via Hydrogen Bonds and N···N Interactions as a New Precursor for Preparation Zinc(II) Oxide Nanoparticles, Thermal, Spectroscopic and Structural Studies

A new 1D supramolecular involving two different ligands, {[Zn(GB)₂]·(μ-bpe)₃} _n (ClO₄)_2n ·nH₂O (GB = 2-guanidinobenzimidazole and bpe = 1,2-bis(4-pyridyl)ethylene, has been synthesised, characterized by elemental analysis, IR-, ¹H NMR-, ¹³C NMR spectroscopy. The thermal stability of compound {[Zn(GB)₂]·(μ-bpe)₃} _n (ClO₄)_2n ·nH₂O was studied by thermal gravimetric and differential thermal analyses. The single crystal X-ray analysis shows that the complex is a one-dimensional polymer involving macrocycle rings as a result of non-covalent bridging bpe ligands via N–H···N and N···N interactions, N–H···bpe···bpe···H–N, with the basic repeating {[Zn(GB)₂](μ-bpe)₃}(ClO₄)₂·H₂O units and by connecting [Zn(GB)₂]²⁺ nodes. ZnO nanoparticles were obtained by calcination of compound {[Zn(GB)₂]·(μ-bpe)₃} _n (ClO₄)_2n ·nH₂O at 500 °C in air. The nanoparticles were characterized by X-ray diffraction and scanning electron microscopy.     

Cobalt(II), Zinc(II) and Cadmium(II)-Squarate Complexes with N-Methylimidazole

Three M(II)-squarate complexes, [Co(sq)(H₂O)(Nmim)₄] (1), [Zn(μ_1,3-sq)(H₂O)₂ (Nmim)₂] _n (2) and [Cd(μ_1,3-sq)(H₂O)₂(Nmim)₂] _n (3) (sq = squarate, Nmim = N-methylimidazole) have been synthesized and characterized by elemental, spectral (IR and UV–Vis.) and thermal analyses. The molecular structures of the complexes have been investigated by single crystal X-ray diffraction technique. The squarate ligand acts as two different coordination modes as a monodentate (in 1) and bis(monodentate) (O ^1– O ³ ) bridging ligand (in 2, 3). The Co(II) atom has a distorted octahedral geometry with the basal plane comprised of three nitrogen atoms of Nmim ligands and a oxygen atom of squarate ligand. The axial position is occupied by a nitrogen atom of Nmim and one aqua ligand. The crystallographic analysis reveals that the crystal structures of 2 and 3 are one-dimensional linear chain polymers along the c and b axis, respectively. The configuration around each metal(II) ions are distorted octahedral geometry with two nitrogen atoms of trans-Nmim, two aqua ligands and two oxygen atoms of squarate-O¹,O³ ligand. These chains are held together by the C–H···π, π···π and hydrogen-bonding interactions, forming three-dimensional network.     

An Infinite Sandwich-Type Copper (I) Coordination Polymer Containing 2-D Double Chains Layers Structure Intercalated with the Terephthalic Acid Layers

A high-quality single crystal structure of a new coordination polymer having the formula [Cu₂(μ-SO₄)(μ-bpy)₂ · (H₂ta)] _n (1) (H₂ta = terephthalic acid; bpy = 4,4′-bipyridine) was obtained when the in situ reaction of CuSO₄ · 5H₂O with H₂ta and bpy ligands under solvothermal conditions (H₂O/ethanol) were carried out. The results of the structural characterization show that Cu(I) ions are bridged by 4,4′-bipyridine to form infinite 1-D chains, which are further linked through the sulfate groups to form a 1-D double chain structure. The extensive hydrogen-bonding interactions between the sulfate anions and free terephthalic acid molecules have an important effect in generating the 2-D layer structures and finally an infinite 3-D sandwich-type coordination polymer. In addition, the luminescent properties of coordination polymer 1 are also discussed.     

Seven Coordinated Metal Complexes derived from (3-Carboxymethoxy-Naphthalen-2-yloxy)-Acetic Acid and Coordination Polymers

A design principle for seven coordinated metal carboxylate complexes and coordination polymers of Mn(II), Cd(II) and Na(I) derived from (3-carboxymethoxy-naphthalen-2-yloxy)-acetic acid (LH2) is presented. The complexes/coordination polymer [Mn(L)(H₂O)₃]·3H₂O (1), [{Cd(L)(H₂O)₂}·H₂O]_n (2); [Cd(L)(py)₃]·3H₂O (3) have metal ions in pentagonal bipyramid environments (py = pyridine). The coordination polymer [{Cd(L)(H₂O)₂}·H₂O]_n (2) may be considered to be the self-assembly of hexacoordinated [Cd(L)(H₂O)₂] units; it reacts with pyridine to form mono-nuclear complex 3. Depending on the reaction conditions, Ni-coordination polymers of L adopt different compositions. From the reaction carried out with NiCl₂ and NaOH in quinoline and water, a hetero bimetallic coordination polymer; namely, [[NaL(H₂O)]₂Ni(H₂O)₄]_n (4) is obtained. A similar reaction in pyridine-water solvent led to [{Ni(L)(py)₃}.py]_n (5). The coordination polymer 5 has pyridine in its interstices held by C–H···π interactions.     

Synthesis and Crystal Structures of Two New Coordination Polymers Based on Diphenic Acid

Two new metal coordination polymers [Zn(dpa)(bim)] _n and [Ni(dpa)(bpp)] _n , (H₂dpa = 3,4′-Biphenyl-dicarboxylic acid, bim = Benzimidazole and bpp = 1,3-Di (4-pyridyl)-propane) have been synthesized and structurally characterized by elemental analysis, IR and X-ray diffraction. Single-crystal X-ray analyses reveal that the 3,4′-diphenic acids act as bridging ligands, exhibiting three coordination modes to link metal ions: μ ₂–η ¹: η ¹, μ ₁–η ¹: η ⁰ and μ ₁ –η¹: η¹. Compound 1 demonstrates a one-dimensional zigzag chain. There exists intermolecular hydrogen bonding interactions in compound 1 which lead to form supramolecular structure. Compound 2 is a two-dimensional (4,4) net, and further assembled twofold interpenetrating net. Furthermore, compound [Zn(dpa)(bim)] _n shows intense photoluminescence at room temperature.     

Two d10 Coordination Polymers Based on the Substitutional Aromatic Multicarboxylate and N-donor Co-ligands: Syntheses, Structures and Luminescent Properties

Two new coordination polymers, formulated as Zn(3-NPA)(1,4-bimb) (1) and Cd(3-NPA)(1,2-bimb)(H₂O) (2) (3-NPAH₂?=?3-nitrophthalic acid, 1,4-bimb?=?1,4-bis(imidazol-1 -ylmethyl)benzene, 1,2-bimb?=?1,2-bis(imidazol-1-ylmethyl)-benzene) have been synthesized by hydrothermal reactions of the semirigid neutral ligand 1,4-bimb or 1,2-bimb with metal ions in the presence of 3-nitro phthalic acid. The two compounds were characterized by infrared spectroscopy, elemental analysis, thermo gravimetric analysis and single-crystal X-ray diffraction analysis. Polymer 1 possesses a new two-dimensional puckered rectangular grid architecture, with the 1,4-bimb ligands displaying a cis-conformation. In polymer 2, the 3-NPA^2? anions coordinate the Cd(II) ions in a tetra dentate mode to form a dimer unit, which is connected by the 1,2-bimb ligands resulting in a single layer. Intra layer hydrogen bond interactions are found between the water molecule and carboxylate oxygen atoms. Weak π···π interactions are observed between the layers through the benzene rings from the adjacent 3-NPA^2? and 1,2-bimb ligands. In addition, the luminescent properties of the two compounds were also investigated in this paper.     

Metal(II) Nicotinamide Complexes Containing Succinato,Succinate and Succinic Acid: Synthesis,Crystal Structures,Magnetic, Thermal,Antimicrobial and Fluorescent Properties

Four novel divalent transitional metal succinates (suc) with nicotinamide (nia), {[M(μ-suc)(H₂O)₂(nia)₂]·2H₂O} _n [M = Mn (1), Ni (2)], [Cu(suc)(nia)₂] (3) and [Ni(H₂O)₄(nia)₂](suc)·(H₂suc) (4), have been synthesized and characterized by elemental analyses, IR and TG-DTA. X-ray analyses of 2 and 4 reveal that they crystallize in a triclinic space group P[`1]. P\bar{1}. Complex 2 is a 1-D coordination polymer, in which the metal(II) ions exhibit an octahedral geometry with two suc, two nia and two aqua ligands. The nia ligand is N-bonded, while the suc ligand bridges the metal centres through the carboxylate groups. 4 contains the [Ni(H₂O)₄(nia)₂]²⁺ complex cations, uncoordinated suc and H₂suc species, which are connected into a two-dimensional layered structure by the combination of N–H⋯O and OW–H⋯O hydrogen bonds. This is one of the scarce examples encountered in coordination chemistry, which contains uncoordinated suc and H₂suc at the same time. The spectroscopic and structural analysis, luminescent and magnetic properties and the antimicrobial activities of the synthesized complexes were investigated.     

Sonochemical Synthesis of New Nano-Belt One-Dimensional Double-Chain Lead(II) Coordination Polymer; As Precursor for Preparation of PbBr(OH) Nano-Structure

Nano-structure of a new 1D double-chain Pb(II) coordination polymer, [Pb(μ-HPDC)(μ-Br)(H₂O)]_n (1), {H₂PDC = 2,3-pyrazinedicarboxylic acid} was synthesized by a sonochemical method. The new nano-structure was characterized by scanning electron microscopy, X-ray powder diffraction, IR spectroscopy and elemental analyses. The structure of compound 1 was determined by single crystal X-ray diffraction and consists of 1D double-chain polymeric units. The coordination number in compound 1 is six and each lead atom is coordinated by two oxygen atoms of HPDC⁻, two nitrogen atoms of HPDC⁻ ligands, one bromide atom and one oxygen of H₂O molecule. The thermal stability of compound 1 was studied by thermal gravimetric and differential thermal analyses. Calcination of the nano-belts of compound 1 at 500 °C under air atmospheres yielded nano-sized particles of PbBr(OH) that characterized by scanning electron microscopy and X-ray powder diffraction.