Reihaneh Malakooti

Facile synthesis of pure non-monoclinic zirconia nanoparticles and their catalytic activity investigations for Knoevenagel condensation

Zirconia nanoparticles were synthesized by the non-hydrolytic thermal decomposition of zirconyl chloride octahydrate in the presence of oleylamine and oleic acid. The nanoparticles were characterized by XRD, HR-TEM and EDAX techniques. TEM observation confirmed that the nanoparticles have an approximately spherical shape with an average size of 3–4 nm and a non-monoclinic structure. Unlike previous approaches, our synthesis of the catalytically relevant (tetragonal and/or cubic) phase of this material did not require (i) an annealing step to stabilize the tetragonal phase, or (ii) the inclusion of dopants. Furthermore, these high surface area tetragonal zirconia nanoparticles showed a good catalytic activity towards the Knoevenagel condensation.

Zirconium Schiff-Base Complex Modified Mesoporous Silica as an Efficient Catalyst for the Synthesis of Nitrogen Containing Pyrazine Based Heterocycles

Zirconium Schiff-base complex modified SBA-15 was synthesized and characterized by powder X-ray diffraction (XRD), BET nitrogen adsorption–desorption methods, IR spectroscopy and thermogravimetric analysis. The XRD and BET analyses show that textural properties of SBA-15 were retained during the grafting procedure. The modified SBA was successfully applied as a heterogeneous catalyst for the synthesis of a library of nitrogen containing pyrazine based heterocycles in good to excellent yields in water media.Graphical AbstractZirconium Schiff-base complex modified mesoporous silica as an efficient catalyst for the synthesis of nitrogen containing pyrazine based heterocycles

An iron Schiff base complex loaded mesoporous silica nanoreactor as a catalyst for the synthesis of pyrazine-based heterocycles

An iron Schiff base complex was encapsulated in SBA-15 mesoporous silica to afford a Fe(III)-Schiff base/SBA-15 heterogeneous nanocatalyst for the synthesis of pyridopyrazine and quinoxaline heterocycles. These reactions proceeded in water with excellent yields. The catalyst was characterized by physico-chemical and spectroscopic methods and found to retain the characteristic channel structures of the SBA-15, allowing good accessibility of the encapsulated metal complex.

Green and Novel Protocol for One-Pot Synthesis of β-Acetamido Carbonyl Compounds Using Mn(bpdo)2Cl2/MCM-41 Catalyst

Aromatic aldehydes were reacted in a one-pot reaction with enolizable ketones, acetonitrile, and acetyl chloride in the presence of Mn(bpdo)2Cl2/MCM-41 under reflux condition or at 80 °C to afford the corresponding β-acetamido ketones in good yields.

Mn-grafted imine-functionalized mesoporous SBA-15 as an efficient catalyst for Knoevenagel condensation under mild conditions

Abstract Surface functionalization of SBA-15 followed by its reaction with manganese acetate has been carried out to develop a new Mn-grafted functionalized mesoporous material and it was characterized by powder X-ray diffraction (XRD), BET nitrogen adsorption–desorption, IR spectroscopy, transmission electron microscopy and diffuse reflectance UV–Vis spectroscopy. The XRD and TEM analyses showed that textural properties of SBA-15 were retained during the grafting procedure and after five-time recycling. The resulting material was successfully applied as a heterogeneous catalyst for Knoevenagel condensation in good to excellent yields under mild conditions.

Environmentally benign and highly regioselective ring opening of epoxides accelerated by ultrasound irradiation

ABSTRACT Regioselective ring opening of aliphatic and aromatic epoxides with nitrogen heterocycles such as indoles and imidazoles was accelerated using an ultrasonic technique as a green approach. An optimized procedure with the catalyst of choice, MCM-41, represents a real alternative to the conventional reaction protocols owing to the catalyst recyclability, simplicity, green conditions and time-saving aspects. GRAPHICAL ABSTRACT

Nanoporous calcined MCM-41 silica for adsorption and removal of Victoria blue dye from different natural water samples

AbstractIn this work, nanoporous MCM-41 silicate was used for the Victoria blue adsorption and removal from the aqueous solutions. The properties of the synthesized MCM-41 were determined by X-ray diffraction analysis, transmission electron microscopy, and TGA analysis. The method is based on the adsorption of Victoria blue after passing on MCM-41 in a column. The adsorption with respect to contact time, pH, flow rate of sample, and initial concentration of analyte was investigated to provide more information about the adsorption characteristics of MCM-41. After adsorption of the dye, the concentrations of residual dye were determined by UV–Vis spectrophotometer. Adsorption process is well described by Langmuir and Temkin isotherms in comparison with Frundlich isotherm. Results suggested that the adsorption of Victoria blue on calcined MCM-41 was a spontaneous and endothermic process. The experimental data fitted very well with the pseudo-second-order kinetic model for Victoria blue onto calcined MCM-41. ...

Electrocatalytic oxidation and determination of dexamethasone at an Fe3O4/PANI–CuII microsphere modified carbon ionic liquid electrode

A novel, simple, sensitive and selective electrochemical sensor based on an Fe3O4/PANI–CuII microsphere modified carbon ionic liquid electrode is constructed and utilized for the determination of dexamethasone. The synthesized Fe3O4/PANI–CuII microspheres are characterized by routine methods such as X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), thermo gravimetric analysis (TGA), and inductively coupled plasma atomic emission spectroscopy (ICP-AES). The Fe3O4/PANI–CuII microspheres can significantly accelerate the electron transfer rate and represent excellent synergistic electrochemical activity for the oxidation of dexamethasone. Differential pulse voltammetry (DPV) was used for the quantitative determination of dexamethasone. As shown, the oxidation peak current is linear with the concentration of dexamethasone in the range of 0.05 to 30 μM with a detection limit of 3.0 nM which is more sensitive than most of the previously reported methods. The proposed method is successfully applied to the sensitive determination of dexamethasone in real samples with satisfactory recoveries.

MoO3 Nanoparticles Synthesis via Hydro-Solvothermal Technique and Its Application as Catalyst for Efficient Ring Opening of Epoxides With Amines Under Solvent-Free Conditions

Molybdenum trioxide nanoparticles were synthesized using ammonium heptamolybdate tetrahydrate (AHM) through a facile hydro-solvothermal technique. The materials were characterized via X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The mean diameter of semispherical α-MoO3 nanoparticles was determined to be 20 ± 5 nm. The catalytic performance of obtained products was examined in the ring opening of epoxides with diverse amines under solvent-free conditions in excellent yields and short period of times.

Synthesis of 2-substituted benzimidazoles and 2-aryl-1H-benzimidazoles using [Zn(bpdo)2·2H2O]2+/MCM-41 catalyst under solvent-free conditions

A cationic zinc(II) complex of the 2,2′-bipyridine-1,1′-dioxide ligand was prepared and loaded onto mesoporous silica nanochannels. The catalyst was characterized by powder X-ray diffraction, transmission electron microscopy, BET nitrogen adsorption–desorption method and FT-IR spectroscopy. The resulting material was used as a new catalyst in a novel and efficient procedure for the synthesis of 2-substituted benzimidazoles and 2-aryl-1H-benzimidazoles by simple condensation of O-phenylenediamine and carboxylic acids under solvent-free conditions.