Electrodeposition of Copper Oxide Nanoparticles on Precasted Carbon Nanoparticles Film for Electrochemical Investigation of anti‐HIV Drug Nevirapine

This work describes the development of a novel electrochemical sensor based on electrodeposition of copper oxide nanoparticles onto carbon nanoparticle (CNP) film modified electrode for the analysis of the anti‐HIV drug, nevirapine (NEV). The electrochemical experiments were performed using linear sweep and cyclic voltammetry. Atomic force microscopy was applied for surface characterization of the deposited modifier film (CuO‐CNP) on glassy carbon electrode (GCE). No oxidation peak was observed for NEV on the bare GCE, but both CNP‐GCE and CuO‐CNP‐GCE showed a distinctive anodic response towards NEV with considerable enhancement (276‐fold and 350‐fold, respectively) compared to CuO‐GCE. The mechanism of the electrocatalytic process on the modified electrode surface was investigated by cyclic and linear sweep voltammetry at various potential sweep rates and pHs of the buffer solutions. The modified electrode exhibited linear dynamic range in three concentration intervals (0.1–0.8, 1–10 and 10–100 µM) with a detection limit of 66 nM. The stability, reproducibility, and repetitive usability exhibited by the proposed modified electrode are good enough to make it a suitable sensor for the determination of NEV in real samples with complex matrices such as human blood serum.     

Dinuclear copper(II) complexes with ethylenediamine derivative and bridging oxalato ligands: solvatochromism and density functional theory studies

Two oxalato-bridged copper(II) complexes of formula, [Cu₂(L¹)₂(µ-ox)](NO₃)₂·H₂O, 1 and [Cu₂(L²)₂(µ-ox)](NO₃)₂·H₂O, 2 (ox = oxalato dianion, L¹ = N,N-dimethyl,N′-benzylethane-1,2-diamine, L² = N,N-diethyl,N′-benzylethane-1,2-diamine), have been synthesized and characterized by elemental analyses, spectroscopic (IR, UV–Vis) data and molar conductance measurements. The crystal structure of complex 1 was determined by X-ray diffraction analysis, revealing two centrosymmetric dinuclear units. The first consists of a [Cu₂(L¹)₂(µ-ox)(NO₃)₂] molecule, in which each Cu(II) center is in a square-pyramidal environment, providing two nitrogen atoms from the diamine-chelating ligands plus two oxygen atoms from the oxalate in the basal plane and an oxygen of the nitrate group in the axial position. The second unit [Cu₂(L¹)₂(µ-ox)(H₂O)₂](NO₃)₂ has a similar structure, but the apical sites are occupied by water ligands and the nitrate anions are free from coordination. Both complexes are solvatochromic. Their solvatochromism was investigated with different solvent parameter models using SPSS/PC and DFT methodology. The solvatochromic behaviors of the complexes were also explored by TD-DFT in ethanol and acetonitrile solvents. The calculated visible absorption spectra were in accord with the experimental results.     

Construction and Application of an Electrochemical Sensor for Simultaneous Determination of Cd(II), Cu(II) and Hg(II) in Water and Foodstuff Samples

By incorporation of synthesized magnetite nanoparticles (Fe₃O₄ NPs) coated with a new Schiff base into carbon paste electrode, a novel modified electrode was constructed for simultaneous determination of ultra trace amounts of Cd(II), Cu(II) and Hg(II). The complexation reaction of Schiff base with metal ions was studied spectrophotometrically. Under optimal conditions a detection limit of 0.20, 0.90 and 1.00 ng mL^?1 for Cd(II), Cu(II) and Hg(II), respectively, was obtained. We take the advantages of the proposed method for simple, rapid, sensitive and selective simultaneous determination of trace amounts of hazardous Cd(II), Cu(II) and Hg(II) in water and foodstuff samples.     

Three-Component Reaction of Triphenylphosphine,Acetylenic Esters,and 6-Aminouracil or 6-Amino-N,N′-dimethyluracil

Protonation of the reactive 1:1 intermediate produced in the reaction of acetylenic esters and triphenylphosphine by 6-aminouracil or 6-amino-N,N′-dimethyluracil leads to vinylphosphonium salts, which undergo Michael addition with the conjugate base of the NH acid to produce highly fanctionalized, salt-free phosphorus ylides in excellent yields.     

DFT Investigation of the Potential of B<Subscript>21</Subscript>N<Subscript>21</Subscript> and Al<Subscript>21</Subscript>P<Subscript>21</Subscript> Nanocages as Anode Electrodes in Metal Ion Batteries

In present paper, the potential of B₂₁N₂₁ and Al₂₁P₂₁ nanocages as anode electrodes of Li-ion, Na-ion and K-ion batteries by using of density functional theory was investigated. The effects of adoption of B₂₁N₂₁ and Al₂₁P₂₁ nanocages with halogen atoms on potential of metal-ion batteries were examined. Results showed that Al₂₁P₂₁ as anode electrode in metal ion batteries has higher potential than B₂₁N₂₁. Results indicated that K-ion battery has higher cell voltage than Li-ion and Na-ion batteries. Results showed that adoption of B₂₁N₂₁ and Al₂₁P₂₁ with halogen atoms increased the cell voltage of metal-ion batteries. Results showed that F-doped metal-ion batteries have higher cell voltage than Cl- and Br-doped metal-ion batteries. It can be concluded that F–Al₂₀P₂₁ as anode electrode in metal-ion battery has higher potential than F–B₂₀N₂₁.     

On the Recollements of Functor Categories

This paper is devoted to the study of recollements of functor categories in different levels. In the first part of the paper, we start with a small category \(\mathcal {S}\) and a maximal object s of \(\mathcal {S}\) and construct a recollement of \(\text {Mod-}\mathcal {S}\) in terms of \(\text {Mod-End}_{\mathcal {S}}(s)\) and \(\text {Mod-}(\mathcal {S}\setminus \{s\})\) in four different levels. In case \(\mathcal {S}\) is a finite directed category, by iterating this argument, we get chains of recollements having some interesting applications. In the second part, we start with a recollement of rings and construct a recollement of their path rings, with respect to a finite quiver. Third part of the paper presents some applications, including recollements of triangular matrix rings, an example of a recollement in Gorenstein derived level and recollements of derived categories of N-complexes.     

Cesium Salt of Tungstosilicic Acid Fabricated by Nano-Casting Strategy: An Efficient Catalyst for the Three-Component Hosomi–Sakurai Reaction

Abstract

We have used SBA-15 silicas as hard templates for the nano-fabrication of Cs_1.8H_2.2SiW₁₂O₄₀ (CsHSiW) salt nanocrystal. The elimination by HF (or NaOH 90 °C) in the silica matrix from the composites occurred by a two-step reaction deposition of CsHSiW salt nanocrystal. The nano-casted CsHPW materials were characterized by several techniques: chemical analysis (atomic absorption, neutron activation analysis, and inductively coupled plasma) and spectroscopic methods (FT-IR spectrum, X-ray diffraction, transmission electron microscopy, and energy dispersive x-ray analysis measurement). In addition to the complete characterization of CsHSiW nanocrystal samples, their catalytic performances are shown for the three-component Hosomi–Sakurai reaction. The reaction proceeds efficiently under ambient conditions with good to excellent yields.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

Glassy carbon electrode modified by new Copper(I) oxide nanocomposite for glucose detection: An electroanalysis study

The Glucose amount of human blood is very vital because in higher levels than allowed value the corporal biological system was hampered. Therefore, in this study, the Cu₂O was deposited on the reduced Graphene oxide (RGO) by polydopamin (PDA) as linker. The new RGO‐PDA‐Cu₂O nanocomposite was deposited on the glassy carbon electrode (GCE) surface after its characterization by UV–Visible, fourier transform infrared (FT‐IR), X‐ray diffraction (XRD), Energy‐dispersive X‐ray (EDX), transmission electron microscopy (TEM) and field emission scanning electron microscopy (FESEM) techniques. The electroanalysis of the new electrode was investigated by the cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) methods. The obtained detection limit of glucose (Glu) showed that the deposited GCE by RGO‐PDA‐Cu₂O nanocomposite has a high potential for its diagnosis. In addition, this electrode was applied to the Glu detection as biosensor in real samples in order to utilize in commercial applications.