Direct Synthesis of CdO Nanoparticles from a Novel Nano-Rods Cadmium(II) 4,4-Difluoro-1-phenyl-1,3-butanedionate Nano Coordination Compound

A novel nano-rods cadmium(II) fluorine-substituted β-diketonate, [Cd(2,2′-bpy)(dfpb)₂] (1), (2,2′-bpy = 2,2′-bipyridine; dfpb = 4,4-difluoro-1-phenyl-1,3-butandion) has been synthesized by a sonochemical method that produces the coordination compound with nano dimensions. The new nanostructure was characterized by scanning electron microscopy, X-ray powder diffraction (XRD) elemental analysis and IR spectroscopy. Compound 1 was structurally characterized by single crystal X-ray diffraction. The single-crystal structure of this complex shows that the coordination number of the Cd^II ions is six with two N-donor atoms from the 2,2′-bpy ligand and four O-donors from two dfpb. Self-assembly of the complex occurs through CH···F–C and π–π stacking interactions. The supramolecular features of 1 are controlled by weak directional intermolecular interactions. CdO nanoparticles were obtained by thermolysis of 1 at 180 °C with oleic acid as a surfactant. The average diameter of the nanoparticles was estimated by the Scherrer equation to be 20 nm. The morphology and size of the CdO samples were further observed using SEM.     

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).     

Synthesis and structural studies of a 1:2 adduct of silver(I) tetrakis(pyrazolyl)borate(III) with a tertiary phosphine

The synthesis and spectroscopic (IR, far-IR, ¹H and ³¹P NMR) characterization of the new complex Ag(pzTp)(PPh₃)₂ is reported, with a single crystal X-ray structure determination showing it to assume the form [(Ph₃P)₂Ag(pz₂Bpz₂)]. Although the silver atom is essentially four-coordinate P₂AgN₂, Ag–P 2.4154(4) Å, 2.5123(4) Å, Ag–N 2.315(1) Å, 2.357(1) Å at ca. 150 K, NMR spectroscopy clearly distinguishes between the bonding character of the two different phosphorus atoms.     

Silver-Doped Organic-Inorganic Hybrid Silica Membranes by Sol-Gel Method: Preparation and Hydrothermal Stability

Silver-doped methyl-modified silica membranes (Ag/M-SiO₂) have been prepared using the sol-gel method by adding AgNO₃ solution to a methyl-modified silica sol. The influence of silver-doping on the physical and chemical structures, thermal stability of –CH₃ groups, and gas permeation performance for the silica membranes were investigated. The metallic silver results from the reduction of AgNO₃ which can be completely transformed after calcined above 200°C. The Si–CH₃ vibrational bands disappear completely when the calcination temperature is increased to 600°C, which mineralized when the calcination temperature is further increased to 750°C. The doping of silver nanoparticles has nearly no influence on the chemical structure of the methyl-modified silica materials and the thermal stability of –CH₃ groups, but can make the mean pore size, total pore volume, H₂ permeability, and H₂/CO₂ selectivities of the silica membranes increase. When operated at 200°C and a pressure difference of 0.35 MPa, the H₂ permeance and H₂/CO₂ selectivity of Ag/M-SiO₂ membrane with the AgNO₃/tetraethylorthosilicate molar ratio of 0.08 is 8.99 × 10^?6 mol · m^?2 · Pa^?1 · s^?1 and 10.22, respectively. After hydrothermal treatment and regeneration, the Ag/M-SiO₂ membranes show a smaller change in gas permeances and H₂/CO₂ permselectivities than the methyl-modified silica membranes without silver-doping.     

Synthesis and Structural Characterization of New Lead(II) Discrete and Infinite Cage-Like Framework: A Precursor to Produce Pure Phase Nano-Sized Lead(II) Oxide

A novel Pb(II) complex, {[Pb₂(tpmba)₂(NO₃)₄]·MeOH} _n (1), was obtained by the reaction of a tripodal ligand, N,N′,N″-tris(pyrid-3-ylmethyl)-1,3,5-benzenetricarboxamide (tpmba), with Pb(NO₃)₂. The structure of complex was determined by X-ray crystallography. The results of structural analysis of the complex reveal that 1 is a M₂L₂ cage-like with a methanol molecule beside the cage. An entirely different structure and topology between 1 and similar complexes indicate that the nature of organic ligands affects the structure of assemblies. The results indicate that the framework of this complex is predominated by the nature of the organic ligand, anions, solvent and geometric need of the metal ions. It was found that the coordination number of Pb^II ions is eight, (PbN₃O₅) has a stereo-chemically active electron lone pair and the coordination sphere is hemi-directed. PbO nanoparticles are obtained by thermolysis of 1 at 180 °C with oleic acid as a surfactant. Scanning electron microscopy shows that the size of the PbO particles is ~30 nm.     

Fabrication of Silver Nanoparticles and 3D Interpenetrated Coordination Polymer Nanorods from the Same Initial Reagents

Nanorods of the three-dimensional coordination polymer, [Ag₂(μ ₂-py-4-c)₂] _n (1) [py-4-c⁻ = pyridine-4-carboxylate], have been synthesized by sonochemical process. The single-crystal X-ray data of compound 1 shows the formation of a 3D interpenetrated silver(I) coordination polymer, which has agostic interactions around the silver(I) ions and two types of Ag^I ions with O₂NAg1···O₂H, N₂ Ag2···O₂H₂ coordination spheres. Silver nanoparticles were fabricated from thermal decomposition of 1 nanorods. These nanostructures were characterized by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). The thermal stability of 1 was studied by thermo gravimetric (TG) and differential thermal (DT) analysis.     

Synthesis,Characterization, Crystal Structures and Thermal and Fluorescence Studies of Dinuclear and Polymeric Silver(I) Complexes of 5,5-Diethylbarbiturate with 2,5-Dimethylpyrazine and Piperazine Involving Ag–Ag Interactions

Two silver(I) complexes, [Ag(dmpyz)₂][Ag(barb)₂] (1) and {[Ag(ppz)][Ag(barb)₂]·H₂O} _n (2) (barb = 5,5-diethylbarbiturate, dmpyz = 2,5-dimethylpyrazine and ppz = piperazine), have been synthesized and characterized by elemental analyses, IR, thermal analysis (TG-DTA) and single-crystal X-ray diffraction. Complex 1 consists of [Ag(dmpyz)₂]⁺ and [Ag(barb)₂]^? ions in which the silver(I) ions are linearly coordinated by two dmpyz or two barb ligands. These two ions are connected by strong Ag–Ag interactions (Ag–Ag = 2.896 (1) Å). Complex 2 is a 1D coordination polymer in which the silver(I) ions are bridged by the ppz ligands in a linear fashion, leading to a zigzag chain of [Ag(ppz)] _n ⁺ , which interacts with the [Ag(barb)₂]^? units by Ag–Ag interactions of 3.183 (1) Å. The 1D chains are further assembled to form 3D networks by strong N–H···O and OW–H···O hydrogen bonds. IR spectra and TG-DTA data are in agreement with the crystal structures. The fluorescent properties of 1 were also evaluated.     

Synthesis and Characterization of One-Dimensional Zinc(II) Coordination Polymers as Precursors for Preparation of ZnO Nanoparticles via Thermal Decomposition

Two new Zn(II) coordination polymers from the ligand, 2,5-bis(3-pyridyl)-3,4-diaza-2,4-hexadiene (bpdh), with different anions; i.e., [Zn(μ-bpdh)(H₂O)₄](ClO₄)₂·2bpdh (1) and [Zn(μ-bpdh)(H₂O)₄](NO₃)₂·2bpdh (2), were synthesized and characterized by IR spectroscopy, elemental analyses and X-ray crystallography. Compounds 1 and 2 are 1D coordination polymers and the zinc atoms are linked by four oxygen atoms from water molecules and two nitrogen atoms of bpdh ligands. There are two uncoordinated bpdh ligands that, along with the perchlorate or nitrate anions, form hydrogen bonds with water molecules. ZnO nanoparticles were obtained by thermolysis of 1–2 in oleic acid at 280 °C in air. The ZnO nanoparticles were characterized by X-ray diffraction and scanning electron microscopy.     

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.     

Perturbation-correlation moving-window two-dimensional correlation spectroscopic studies on the heat treatment of poly(vinyl alcohol)/silver nitrate film

In this paper, poly(vinyl alcohol)/silver nitrate (PVA/AgNO₃) films were annealed at 180 °C for 1 h to prepare highly electrically conductive poly(vinyl alcohol)/silver (PVA/Ag) nanohybrids. Ultraviolet (UV)-visible absorption spectra, X-ray diffraction (XRD) scans, and scanning electronic microscopy (SEM) were applied to investigate the structures and morphology of the PVA hybrids. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were employed to study the thermal property of PVA/AgNO₃ films. Furthermore, perturbation-correlation moving-window two-dimensional (PCMW2D) correlation spectroscopy combined with temperature-dependent Fourier transform infrared (FTIR) spectroscopy was used to investigate the conversion of AgNO₃ into Ag nanoparticles in PVA matrix. The results show that the chelates for AgNO₃ coordinated with hydroxyl groups are primarily decomposed in the temperature regions of 39.7–72.6 °C and 182.7–199.6 °C. AgNO₃ is reduced into Ag⁰ and the hydroxyl groups of PVA are oxidized into carbonyl groups. The PVA-AgNO₃ chelates are very rapidly decomposed in the temperature region of 182.7–199.6 °C. Large amounts of Ag⁰ produced by the reduction of AgNO₃ are aggregated into Ag nanoparticles which are homogeneously dispersed into the PVA matrix. When the temperature increases to 212.7 °C, the unhydrolyzed acetate groups in PVA chains are sharply decomposed.     

Coordination Behaviors and Supramolecular Interactions of 2-(2′-Pyridyl) Imidazoline: Crystal Structure of Its Two Cu(II) Complexes

Two new copper coordination complexes, [Cu(PI)(OX)(H₂O)]·H₂O (1) and [Cu(PI)(fum)(H₂O)]·H₂O (2) [PI = 2-(2′-pyridyl) imidazoline, OX^2? = dianion of oxalic acid and fum^2? = dianion of fumaric acid], were synthesized by interface diffusion method based on Cu(II) ions, PI ligands and aliphatic dicarboxylic acids. Complex 1 is a mononuclear complex which spreads into a 3D (4,9)-connected supramolecular network via hydrogen bond interactions, while complex 2 features a 1D zigzag chain with two different orientations. These two compounds are characterized by single crystal X-ray diffraction, powder X-ray diffraction, elemental analyses, infrared spectra, and thermogravimetric analyses.     

Thermolysis Synthesis of Pure Phase Nano-Sized Cobalt(II) Oxide from Novel Cobalt(II)-Pyrazole Discrete Nano Coordination Compound

Nano-structures of a new discrete coordination compound of divalent cobalt with the pyrazol (pzH) containing the terminal isothiocyanate anions, [Co(pzH)₂(NCS)₂] (1), with discrete molecular architecture in solid state was synthesized by a sonochemical method. The new nanostructure was characterized by scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray powder diffraction, IR, and elemental analysis. The supramolecular features in these complexes are guided and controlled by weak directional intermolecular interactions. The discrete molecules interact with each other through labile interactions creating a 3D supramolecular framework. The CoO nanoparticles were obtained by thermolysis of 1 at 180 °C with oleic acid as a surfactant.     

A (Triphenylphosphine)Silver (I) Complex as a New Performance Additive in Free‐Radical Photopolymerization under Air

Unusual photochemical properties of an Ag(I)‐derived complex, i.e., bis[(µ‐chloro)bis(triphenylphosphine)silver (I)] ([Ag](PPh₃)) are demonstrated when used in free‐radical photopolymerization reactions: i) [Ag](PPh₃) can act as an innovative photoinitiating system when associated with a commercial type I photoinitiator 2,2‐dimethoxy‐2‐phenylacetophenone to overcome the oxygen inhibition effect during the free‐radical photopolymerization of acrylate monomers, thus accelerating the kinetics of polymerization under air; ii) silver‐based nanoparticles can be in situ generated under air, thus leading to new antibacterial coatings which prevent the growth of Escherichia coli and Staphylococcus aureus after few hours of incubation.     

4-Ethynylphenoxy Cyclo- and Poly(phosphazenes) and Their Reactions with Dicobalt Octacarbonyl

4-Ethynylphenoxy derivatives of the cyclo- and polyphosphazenes N₃P₃(OC₆H₄CCH)₆ and [NP(OC₆H₄CCH) _x (OC₆H₅)_2–x ] _n (x = 0.04–0.38) were prepared in three steps starting from commercially available materials. TGA studies show that the addition of the ethynyl group to the polymers results in significantly increased thermal stability and char yields. Pyrolysis mass spectrometry data indicates the absence of cyclic depolymerization products in the thermolysis. The reactions of the ethynylphenoxy cyclo- and polyphosphazenes with dicobalt octacarbonyl lead to the thermally labile dicobalt hexacarbonyl complexes N₃P₃(OC₆H₄CCH·Co₂(CO)₆)₆ and [NP(OC₆H₄CCH·Co₂(CO) ₆ ^? ) _x (OC₆H₅)_2–x ] _n . TGA and pyrolysis mass spec show that the complexes start to loose CO at temperatures as low as 40 °C. Heating the polymeric complex at 200 °C in vacuo leads to complete elimination of CO leaving cobalt nanoparticles in a polymer matrix.     

Isomer Directed Synthesis of Two 3D Cadmium(II) Compounds: Structure Variation and Energetic Performance

Two inorganic mixtures of copper and sodium compounds have been synthesized and characterized with different measurement techniques. The thermal property of these mixtures has been studied to low temperature up to 223 from 573 K with DSC. The specific heat capacity of this mixture has been measured in atmospheric O₂ at a rate of 10 K min^?1 from 573 to 223 K and vice versa in two thermal cycles. The net specific heat capacity of these mixtures is found endothermic in first and second thermal cycles. The net specific heat capacity of 0.5Cu₂(PO₄)(OH); 3.5CuH(PO₄)₂·H₂O; 2NaHSO₄·H₂O (CuPHS) during first thermal cycle is ?71203.05 J kg^?1 K^?1 and in second thermal cycle is ?73881.67 J kg^?1 K^?1 between temperature range of 303–223 K. The net specific heat capacity of mixture 0.5Cu₂(PO₄)(OH); 3.5CuH(PO₄)₂; 2Na₂SO₄(CuPS) in first thermal cycle is ?21158.37 J kg^?1 K^?1 and in second thermal cycle is?45739.92 J kg^?1 K^?1 between temperature range of 298–573 K. As both mixtures are endothermic in nature in all cycles, it can be used as heat storage material.The average crystallite size of mixture 0.5Cu₂(PO₄)(OH); 3.5CuH(PO₄)₂·H₂O; 2NaHSO₄·H₂O and 0.5Cu₂(PO₄)(OH); 3.5CuH(PO₄)₂; 2Na₂SO₄ is ~47 and ~17.3 nm, respectively.     

A New Cd(II) Coordination Polymer with a Rare tfz-d Topology Constructed by Asymmetrically Tricarboxylate and Imidazole-Containing Ligand: Synthesis,Crystal structure and Luminescent Property

A new coordination polymer [Cd(Hbtc)(bib)_0.5] _n (1) (H₃btc = biphenyl-3,4′,5-tricarboxylate and bib = 1,4-bis(imidazol-1-yl)benzene) has been obtained under hydrothermal conditions. The structure of complex 1 has been determined by single-crystal X-ray diffraction analysis and further characterized by elemental analysis and IR spectrum. The complex 1 shows a (3,8)-connected twofold interpenetrated three-dimensional (3D) tfz-d topology with the point symbol (4³)₂ (4⁶·6¹⁸·8⁴). The photoluminescence behavior of complex 1 was also discussed in paper.     

Synthesis and Characterization of Pure Phase Zn(II) and Cd(II) Oxide Nanoparticles via Thermal Decomposition of Four New Zn(II) and Cd(II) Coordination Polymers

Four new Zn(II) and Cd(II) coordination polymers, [Zn(2-AMP)₂(N₃)₂]_n (1), [Zn(2-AMP)₂(SCN)₂]_n (2), [Cd(2-AMP)(N₃)₂]_n (3) and [Cd(2-AMP)₂(SCN)₂]_n (4) {2-AMP: 2-Aminomethylpyridine}, have been synthesized and characterized by single crystal X-ray diffraction, IR spectroscopy and elemental analyses. The Zinc(II) oxide and Cadmium(II) oxide nano-particles have been synthesized from thermolysis of 1–4 at 600 °C under air atmosphere for 4 h. The ZnO and CdO nanoparticles were characterized by X-ray diffraction and scanning electron microscopy (SEM). SEM images show the average size of produced ZnO and CdO nanoparticles are 60–70 nm in all compounds.     

Direct Synthesis of Cd3OSO4 Nano-particles From a New Three-dimensional Cadmium(II) Coordination Polymer Precursor

A new three-dimensional Cd(II) coordination polymer, {[Cd₃(3-pyc)₄(NCS)₂(H₂O)₄]·2H₂O} _n (1); 3-Hpyc = 3-pyridinecarboxylic acid, was prepared and characterized by elemental analyses and IR spectroscopy. Compound 1 was structurally characterized by single-crystal X-ray diffraction. The structural determination shows that the compound is a new 3D coordination polymer has different environments containing CdO₅NS and CdO₂N₄ units. This polymeric precursor has been used in the preparation of Cd₃OSO₄ nanoparticles by thermolysis in oleic acid. The new nano-structure of Cd₃OSO₄ was characterized by scanning electron microscopy and X-ray powder diffraction. This study demonstrates that coordination polymers may be suitable precursors to the preparation of desirable nanoscale materials.     

Bis-boron-capped tris(dioxime) cage complexes with terminal carbonyl groups

Three clathrochelate complexes, [(p-OHCC₆H₄B)₂(chdd)₃Fe^II]·0.5CH₂Cl₂ (1·0.5CH₂Cl₂, H₂chdd = 1,2-cyclohexanedione-1,2-dioxime), [(p-OHCC₆H₄B)₂(hmbd)₃Mn^II₂]}·Et₃NH·0.5CH₃OH·0.5H₂O (2·0.5CH₃OH·0.5H₂O, H₃hmbd = 2-hydroxy-5-methyl-1,3-benzenedicarboxaldehyde-1,3-dioxime), and [(p-OHCC₆H₄B)₂(hmbd)₃Co^II₂]·Et₃NH·H₂O (3·H₂O), were synthesized through template macrobicyclization using metal-oximates as building blocks. These complexes contained reactive apical formyl substituents. Fe^II in mononuclear complex 1 was wrapped in the cavity formed by condensation of H₂chdd with 4-formylphenylboron acid. The organic frameworks of anion unit of binuclear Mn^II complex 2 and that of binuclear Co^II complex 3 were combined by H₃hmbd with 4-formylphenylboronic acid. Spectroscopic, electrochemical characterizations of complexes 1–3 were exploited. DFT calculation of 1 and 2 was also done for better understanding of the electronic property and charge carrier mobility.     

Synthesis of dendritic silver nanostructures and their application in hydrogen peroxide electroreduction

Well-defined silver (Ag) dendritic nanostructures were successfully synthesized by electrodeposition without the use of any template or surfactant. X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were employed to investigate the as-prepared Ag nanomaterials. These dendrites are aggregates of Ag nanoparticles, which are highly crystalline in nature. The concentration of AgNO₃ affects the shape of the nanoparticles. In addition, the electrochemical properties of the Ag dendrite-modified glassy carbon electrode (Ag/GC) were characterized by cyclic voltammetry and chronoamperometry. Results indicated that the as-obtained Ag dendrites exhibited favorable electroreduction activity towards oxygen (O₂) and hydrogen peroxide (H₂O₂). When used as a sensor, the Ag/GC electrode exhibited a wide linear range of 0.005–12 mM H₂O₂, with a remarkable sensitivity of 7.39 μA/mM, a detection limit of 0.5 μM, estimated at a signal-to-noise ratio of 3, and a rapid response time (within 5 s). Moreover, the electrode showed good reproducibility, anti-interferant ability and long-term stability.