Electrodeposited Ni(OH)<Subscript>2</Subscript> nanostructures on electro-etched carbon fiber paper for highly stable supercapacitors

Herein, we introduce a facile, inexpensive and fast, and additive-/template-free method to fabricate highly stable nickel hydroxide nanofibers for supercapacitor applications. Ni(OH)₂ nanofibers were electrodeposited on electro-etched carbon fiber paper by a potential step method (Ni(OH)₂-ECFs) and characterized using scanning electron microscopy and X-ray diffraction analysis. Electrochemical performance of Ni(OH)₂-ECF was studied in symmetric two-electrode assembly by cyclic voltammetry, galvanostatic charge–discharge method, and electrochemical impedance spectroscopy. A specific capacitance of 277.5 F g^?1 was achieved for the symmetric supercapacitor based on two identical Ni(OH)₂-ECFs. Our findings demonstrate high-rate capability with excellent stability (approximately 100 % capacitance retention) for Ni(OH)₂-ECF supercapacitor, originated from the intimate contact between Ni(OH)₂ and ECF. Our studies suggest the Ni(OH)₂-ECF electrode as an excellent material for supercapacitor applications.     

Synthesis,Structural and Energetic Properties of Copper(II) Perchlorate Complex with Aminoguanidine

The complexation of copper(II) perchlorate with aminoguanidine hemesulfate (AGHS) yield related mononuclear complex bis(aminoguanidine)copper(II) perchlorate; [Cu(AG)₂](ClO₄)₂ ( I ). The characterization of complex I was done by elemental analysis, electronic spectra, IR studies, and X‐ray diffraction. From analytical data, a stoichiometry of 1:2 of metal to ligand was determined for the complex. The structure consists of centrosymmetric square planar [Cu(AG)₂]²⁺ cations and perchlorate counterions. The Cu^II atom is four‐coordinate by two imine N atoms and two amine N atoms from two aminoguanidine ligands, forming a slightly distorted square‐planar coordination. In the crystal structure, molecules are linked through intermolecular N–H ··· O hydrogen bonds, forming a network. The thermal decomposition process of this complex was investigated through differential scanning calorimetry (DSC) and the sensitivities toward impact and friction were assessed using a BAM drophammer and a BAM friction tester.     

Using experimental methods and CSD data for investigating the products of the reaction between 2-((2-aminoethyl)amino)ethanol with CdI2 and CdI2/HgI2-mixtures

The binding modes of 2-((2-aminoethyl)amino)ethanol-based ligands were explored using the Cambridge Structural Database (CSD). To extend this field, a new cadmium complex containing 2-((2-aminoethyl)amino)ethanol (AEAE), [Cd(AEAE)₂][Cd(AEAE)₂]′[CdI₄]₂ (1), was prepared and characterized by spectroscopic methods and single-crystal X-ray diffraction. The reaction of AEAE with a 1:1 mixture of CdI₂ and HgI₂ was also investigated. The complex, [Cd(AEAE)₂][I₂Hg(μ-I₂)₂HgI₂] (2), was synthesized and characterized. Compounds 1 and 2 represent the first tridentate binding modes of an AEAE type ligand with Cd²⁺. Geometrical investigation for complexes containing Cd(N^amine₂O^alcohol)₂, CdI_n, and HgI_n environment were carried out using the CSD software. Also different possible diastereomers which can be formed in coordination of a pair of tridentate AEAE ligands in octahedral geometry were studied and discussed.     

Structural Relationships and Theoretical Study of Electron Transfer Properties of 1,3,2-Dithiazolyl Radicals with Fullerenes in Nanostructure [1,3,2-DTA(s)]@Cn Supramolecular Complexes

Various empty carbon fullerenes with different carbon atoms have been obtained and investigated. The dithiazolyl radicals have shown important electron-transfer properties. Topological indices are digital values that are assigned based on chemical composition. These values are purported to correlate chemical structures with various chemical and physical properties. They have been successfully used to construct effective and useful mathematical methods to establish clear relationships between structural data and the physical properties of these materials. In this study, the number of carbon atoms in the fullerenes was used as an index to establish a relationship between the structures of 2,3-naphthalene-1,3,2-dithiazolyl (NDTA), 2,3-quinoxaline-1,3,2-dithiazolyl (QDTA), and 1,2,5-thiazolo[3,4-b]-1,3,2-dithiazolo[3,4-b]pyridazin-2-yl (TDP-DTA), radicals, 1–3 as molecular conductor radicals and fullerenes C_n (n = 60, 70, 76, 82, and 86), which create [1,3,2-DTA(s)]@C_n, A-1 to A-5 (NDTA]@C_n), B-1 to B-5 ([QDTA]@C_n), and C-1 to C-5 ([TDP-DTA]@C_n). The relationship between the number of carbon atoms and the free energies of electron transfer (ΔG_et(1) to ΔG_et(4) ) are assessed using the Rehm–Weller equation for A-1 to A-5, B1 to B-5, and C-1 to C-5 supramolecular [1,3,2-DTA(s)]@C_n complexes. Calculations are presented for the four reduction potentials ( ^Red.E₁ to ^Red.E₄ ) of fullerenes C_n . The results were used to calculate the four free energies of electron transfer (ΔG_et(1) to ΔG_et(4) ) of supramolecular complexes A-1 to A-18, B-1 to B-18, and C-1 to C-18 (5–60) for fullerenes C₆₀ to C₃₀₀.     

Analysis of Variance (ANOVA) for Optimizing the Nano-SiO2 Content of High Performance Epoxy Nanocomposites

Epoxy based nanocomposite samples containing SiO₂ nanoparticles (0.0–3.0 %w) were prepared for physical and mechanical evaluation. Some thermomechanical and physical properties of samples were investigated using dynamic mechanical analysis (DMA), tensile strength, hardness and abrasion tests. The main aim of experimentation was to realize the optimum amount of nano-SiO₂ which would demonstrate the best improving effect on mechanical and physical properties of nanocomposite samples and finding how significant a factor is for improving in physical and mechanical properties. Analysis of variance (ANOVA) was applied for optimization of SiO₂ content in epoxy based nanocomposites.     

Ionene supported peroxodisulfates: Polymeric reagents for the oxidative deprotection of <Emphasis Type="Italic">TMS</Emphasis> and <Emphasis Type="Italic">THP</Emphasis> ethers and oxidative cleavage of the C=N bond in water

Oxidative deprotection of trimethylsilyl and tetrahydropyranyl ethers, and deprotection of phenylhydrazones, semicarbazones, and oximes to their corresponding carbonyl compounds carried out in water at reflux condition using ionene supported peroxodisulfates is reported. The reagents are recyclable and products are obtained in excellent yield under environmentally benign conditions without overoxidation to carboxylic acid. Correspondence: Moslem Mansour Lakouraj, Department of Chemistry, Mazandaran University, Babolsar, Iran.     

Investigation of the effect of the N‐oxidation process on the interaction of selected pyridine compounds with biomacromolecules: structural,spectral, theoretical and docking studies

Two new N‐oxide compounds, namely glycinium 2‐carboxy‐1‐(λ¹‐oxidaneyl)‐1λ⁴‐pyridine‐6‐carboxylate–glycine–water (1/1/1), C₂H₆NO₂⁺·C₇H₄NO₅^?·C₂H₅NO₂·H₂O or [(2,6‐HpydcO)(HGLY)(GLY)(H₂O)], 1 , and methyl 6‐carboxy‐1‐(λ¹‐oxidaneyl)‐1λ⁴‐pyridine‐2‐carboxylate, C₈H₇NO₅ or 2,6‐HMepydcO, 2 , were prepared and identified by elemental analysis, FT–IR, Raman spectroscopy and single‐crystal X‐ray diffraction. The X‐ray analysis of 1 revealed an ionic compound containing a 2,6‐HpydcO^? anion, a glycinium cation, a neutral glycine molecule and a water molecule. Compound 2 is a neutral compound with two independent units in its crystal structure. In addition to the hydrogen bonds, the crystal network is stabilized by π–π stacking interactions of the types pyridine–carboxylate and carboxylate–carboxylate. The thermodynamic stability and charge‐distribution patterns for isolated molecules of 2,6‐H₂pydcO and 2,6‐HMepydcO, and their two similar derivatives, pyridine‐2,6‐dicarboxylic acid (2,6‐H₂pydc) and dimethyl 1‐(λ¹‐oxidaneyl)‐1λ⁴‐pyridine‐2,6‐dicarboxylate (2,6‐Me₂pydcO), were studied by density functional theory (DFT) and natural bond orbital (NBO) analysis, respectively. The ability of these compounds and their analogues to interact with nine selected biomacromolecules (BRAF kinase, CatB, DNA gyrase, HDAC7, rHA, RNR, TrxR, TS and Top II) was investigated using docking calculations.     

Preparation and characterization of flexible polyurethane foam nanocomposites reinforced by magnetic core-shell Fe3O4@APTS nanoparticles

Novel magnetic polyurethane flexible foam nanocomposites were synthesized by incorporation of aminopropyltriethoxysilane (APTS) functionalized magnetite nanoparticles (MNPs) via one-shot method. The functionalized MNPs (Fe₃O₄@APTS) were synthesized by co-precipitation of the Fe²⁺ and Fe³⁺ with NH₄OH and further functionalization with APTS onto the surface of MNPs by sol–gel method. The magnetic core-shell NPs were used up to 3.0 % in the foam formulation and the magnetic nanocomposites prepared successfully. The results of thermogravimetric analysis (TGA) showed an increasing in thermal stability of polyurethane nanocomposite foam at initial, 5 and 10 %, and maximum thermal decomposition temperatures by incorporation of Fe₃O₄@APTS. In addition SEM images revealed the uniformity of the foam structures and decreasing in pore sizes. Furthermore, VSM result showed super paramagnetic behavior for Fe₃O₄@APTS-PU nanocomposites.     

热分解双(2-氨基烟酸)锌(Ⅱ)制备的介孔微砖ZnO纳米颗粒的光催化活性(英文)

Hollow microblocks of [Zn(anic)_2], as a novel coordination compound, were synthesized using 2-aminonicotinic acid(Hanic) and zinc(Ⅱ) nitrate tetrahydrate. The chemical composition of the zinc complex, ZnC_(12)H_(10)N_4O_4, was determined by Fourier transform infrared(FTIR) spectroscopy and elemental analysis. The synthesized zinc complex was used as a precursor to produce ZnO nanostructures by calcination at 550 °C for 4 h. Morphological studies by scanning electron microscopy and transmission electron microscopy revealed the formation of porous microbricks of ZnO nanoparticles. N_2 adsorption-desorption analysis showed that the obtained ZnO microbricks possess a mesoporous structure with a surface area of 8.13 m~2/g and a pore size of 22.6 nm. The X-ray diffraction pattern of the final product proved the formation of a pure ZnO composition with a hexagonal structure. Moreover, FTIR analyses showed that the 2-aminonicotinic acid ligand peaks were absent after the calcination step. Diffuse reflectance spectroscopy was used to determine the band gap energy of the produced ZnO and it was about 3.19 eV. To investigate the photocatalytic activity of the porous ZnO nanostructure, a series of photocatalytic tests were carried out to remove Congo red, as a representative toxic azo dye, from aqueous solution. The results show that the product can be used as an efficient photocatalyst for waste water treatment with high degradation efficiency.