Metal-Assisted Oxidative Cyclization of Arylamidrazones I. Synthesis of 3-Acetyl-1,4-dihydro-1-phenyl-1,2,4-benzotriazine

In the presence of RuCl₃, N-phenylamidrazone underwent oxidative cyclization into 1,4-dihydro-1-phenyl-1,2,4-benzotriazine, the structure of which is established by spectral and X-ray diffraction data.     

The vapour pressures and saturated volumes of benzotrifluoride in the temperature range 460–530K.

A sample of benzotrifluoride was degassed in a high vacuum train, and the vapor pressure was measured in the temperature range 460 – 53OK. Also the saturated vapour and saturated liquid volumes were measured. Two simple equations were used to fit the vapour pressure data by the least square method. The heat of vaporization was calculated using Clapeyron equation.     

New many fold 1,2,3‐selenadiazole aromatic derivatives

The many fold aromatic ketones 2a‐d are versatile compounds for the synthesis of the many fold 1,2,3‐selenadiazole aromatic derivatives 5a‐d . The preparation starts with the reaction between the many fold bromomethylene benzene derivatives 1a‐d and 4‐hydroxyacetophenone, which are transformed through the reaction with semicarbazide hydrochloride or ethylhydrazine carboxylate into the corresponding semicarbazones derivatives 3a‐d or hydrazones 4a‐d . The reaction with selenium dioxide leads to regiospecific ring closure of semicarbazones or hydrazones to give the many fold 1,2,3‐selenadiazole aromatic derivatives in high yield.     

Gamma-irradiation effects on the electrical conductivity of pure and Cu-doped Fe3O4 spinel

The electrical conductivity and IR-spectra of pure and Cu-doped Fe₃O₄ spinels were measured at 300–1000 K. Two breaks in the conductivity-temperature curves have been observed for all investigated pure and doped samples. One of these two breaks were found near the Curie point of the investigated spinel. The electrical conduction in -irradiated and non-irradiated pure and Cu-doped Fe₃O₄ occurred by a hopping mechanism due to a fast electron exchange between Fe²⁺ and Fe³⁺-ions present on octahedral sites. The Seebeck-voltage of the irradiated and non-irradiated pure and Cu-doped samples has been measured. The effect of -irradiation on the conductivity values //, activation energy and type of defects was discussed.     

Investigation on corrosion inhibition and adsorption mechanism of azomethine derivatives at mild steel/0.5 ​M ​H2SO4 solution interface: Gravimetric,electrochemical, SEM and EDX studies

The inhibition performance of five azomethine derivatives such as: 1-(4-Methyloxy phenylimino)-1-(phenylhydrazono)-propan-2-one (SB₁), 1-(4-Methylphenylimino)-1-(phenylhydrazono) propan-2-one (SB₂), 1-(phenylimino)-1(phenylhydrazono)-propan-2-one (SB₃), 1-(4-Bromo phenylimino)-1(phenylhydrazono)-propan-2-one (SB₄) and 1-(4-Chlorophenylimino)-1(phenylhydrazono) -propan-2-on (SB₅) as corrosion inhibitors for mild steel in sulfuric acid 0.5 ?M were investigated using different methods. All experimental results demonstrate that these compounds are eficients inhibitors. The inhibition efficiencies ($IE$) increase with inhibitors concentration. At 7.5 $\times$ 10^?5 ?M, the $IE$ was 97.27%, 96.31%, 94.23%, 93.19 and 91.64% for SB₁, SB₂, SB₃, SB₄ and SB₅, respectively. The potentiodynamic polarization results indicated that all the studied inhibitors act as mixed type. The adsorption process on mild steel surface obeyed Langmuir isotherm. The associated activation parameters and thermodynamic have been calculated and discussed. The adsorbed film formed on the metal surface was characterized by SEM and EDX.     

Observation on Symmetry Properties of Sodium Zinc(II)-2,9,16,23-phthalocyanine Tetracarboxylate in Water:NaOH Solution

The shift of the Q-band of sodium zinc(II)-2,9,16,23-phthalocyanine tetracarboxylate (ZnPc(COONa)₄) to about 800 nm is attributed to the influence of the electron-donating property of the carboxylate groups substituted in the β–position. ZnPc(COONa)₄ which was found to have a symmetry of D _2h characterized by a splitting of the Q transition. This splitting was interpreted by the formation of dianionic symmetric ZnPc(COONa)₄ resulting from the dissociation of the pyrrole protons as well as the possibility of Na⁺ dissolution of ZnPc(COONa)₄ in the aqueous solution of NaOH.     

Nonlinear planar optical waveguide sensors comprising metamaterial guiding films at terahertz frequencies

In this paper, we propose a metamaterial film bounded by a nonlinear cover and a dielectric substrate as a THz wave sensor. The dispersion characteristics and magnetic field profiles have been derived, computed and analyzed. Confinement of the light waves was found to increase with both nonlinearity and frequency. We believe our results can be used to design novel tunable future sensors.     

Fe3O4‐supported Schiff‐base copper (II) complex: A valuable heterogeneous nanocatalyst for one‐pot synthesis of new pyrano[2,3‐b]pyridine‐3‐carboxamide derivatives

A novel Cu (II) Schiff‐base complex immobilized on core‐shell magnetic Fe₃O₄ nanoparticles (Fe₃O₄@SPNC) was successfully designed and synthesized. The structural features of these nanoparticles were studied and confirmed by using various techniques including FT‐IR spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy‐dispersive X‐ray spectroscopy (EDS), vibrating sample magnetometer (VSM), X‐Ray diffraction (XRD), wavelength dispersive X‐ray spectroscopy (WDX), and inductively coupled plasma (ICP). These newly synthesized nanoparticles have been used as efficient heterogeneous catalytic system for one‐pot multicomponent synthesis of new pyrano[2,3‐b]pyridine‐3‐carboxamide derivatives. Notably, the catalyst could be easily separated from the reaction mixture by using an external magnet and reused for several successive reaction runs with no significant loss of activity or copper leaching. The present protocol benefits from a hitherto unreported MNPs‐immobilized Cu (II) Schiff‐base complex as an efficient nanocatalyst for the synthesis of newly reported derivatives of pyrano[2,3‐b]pyridine‐3‐carboxamide from one‐pot multicomponent reactions.     

High-performance hybrid supercapacitor based on pure and doped Li4Ti5O12 and graphene

Journal of Solid State Electrochemistry - Graphene nanosheets (G) and pure, as well as doped Mg-, Mn-, V-Li4Ti5O12, spinel structure have been synthesized. As-prepared materials were characterized...     

The Potential of O‐MMT as a Reinforcing Filler for Uncured and Dynamically Cured PVC/XNBR Composites

Organic montmorillonite modified with quaternary ammonium (O‐MMT) was compounded with uncured and dynamically cured poly(vinyl chloride)/carboxylated nitrile butadiene rubber (PVC/XNBR) composites, using a Brabender Plasticorder at 130°C and 50 rpm rotor speed. The reinforcing efficiency of the O‐MMT was investigated in the uncured PVC/XNBR composite and the dynamically cured PVC/XNBR counterpart. Mixing and dynamic curing of the composites were monitored by typical torque‐time curves derived from a Brabender internal mixer. The torque‐time curves revealed that the dynamic curing process was successful and the incorporation of O‐MMT has no adverse effect on the processibility of the composites. It has been found that the introduction of crosslinks within the rubbery phase in the presence of the O‐MMT has further improved the tensile properties. DMA studies revealed that dynamically cured composite with O‐MMT showed higher storage modulus than the composite without O‐MMT. Furthermore, a one‐step tensile modulus vs. temperature curve and a related one peak tensile loss modulus vs. temperature curve were obtained, consequently, both are characteristics of a miscible polymers system. Further evidence on the composite miscibility was purchased by thermal scans from DSC, which showed a single glass transition temperature of PVC/XNBR composites. This claim was further supported by ATR‐IR spectra which revealed that hydrogen bonding is extensively involved in PVC/XNBR composites. This evidence unveiled the exact nature of the specific interactions responsible for miscibility and hence, enhanced mechanical properties. Furthermore, we proved in our studies the reinforcing role played by layered clay due to better dispersion, as well as improved interactions.