Synthesis,characterization and theoretical and fluorescence emission microscopy studies of new Pd/Pt–cyclopropa[60]fullerene complexes: Application of Taguchi method for optimization of parameters in Suzuki–Miyaura reaction

The reactions of unsymmetric phosphorus ylides of the type [Ph₂P(CH₂)_nPPh₂?C(H)C(O)C₆H₄‐p‐CN] (n = 1 (Y¹); n = 2 (Y²)) with C₆₀ and M(dba)₂ (M = Pd or Pt; dba = dibenzylideneacetone) are reported. Based on the various coordination modes of these ylides in complexation, the following new Pd/Pt–cyclopropa[60]fullerene complexes were obtained: P,C‐coordinated [(η²‐C₆₀)Pd(κ²‐Y¹)] ( 1 ) and [(η²‐C₆₀)Pt(κ²‐Y¹)] ( 2 ) complexes and P‐coordinated [(η²‐C₆₀)Pd(Y²)₂] ( 3 ) and [(η²‐C₆₀)Pt(Y²)₂] ( 4 ) complexes. These compounds were characterized using Fourier transform infrared, UV–visible and NMR (¹H, ¹³C and ³¹P) spectroscopies and scanning electron microscopy. Furthermore, cytotoxicity studies showed that nanoparticles of these complexes can be used as non‐toxic labels for cellular imaging application. Also energy decomposition analysis results revealed that the percentage contribution of ΔE_elec in total interaction energy is considerably larger than that of ΔE_orb. Thus, in all complexes the (η²‐C₆₀)M? (Y¹) bond is considerably more electrostatic in nature than the (η²‐C₆₀)? M(Y¹) bond. Finally, by application of the Taguchi method for optimization of parameters in Suzuki–Miyaura reaction, the catalytic activity of Pd complexes 1 and 3 was investigated in the cross‐coupling reaction of various aryl chlorides with phenylboronic acid. According to analysis of variance results, solvent has the highest F value and it has high contribution percentage (36.75%) to the yield of Suzuki–Miyaura reaction.     

Photochemical approach toward deposition of gold nanoparticles on functionalized carbon nanotubes

The development of new methods for the facile synthesis of hybrid nanomaterials is of great importance due to their importance in nanotechnology. In this work, we report a new method to deposit Au nanoparticles on the surface of single-walled carbon nanotubes (SWCNTs). Our approach consists of a one pot synthesis in which Au nanoparticles are generated in the presence of a photoreducing agent (Irgacure-2959) and carboxyl or polymer-functionalized SWCNTs (f-SWCNTs). We have observed that when carbon nanotubes are functionalized with polymers containing pendant amino groups, the latter can act as specific nucleation sites for well-dispersed deposition of Au nanoparticles. The surface coverage of the Au nanoparticles can be observed by transmission electron spectroscopy. These observations are compared to that of carboxyl functionalized SWCNTs, in which less surface coverage was observed. The f-SWCNT/Au nanocomposites were also characterized by UV-vis, infrared, and Raman spectroscopy and thermogravimetric analysis (TGA). This facile and effective route can be implemented to deposit gold nanoparticles on other surface-functionalized carbon nanotubes.     

New method based on combining ultrasonic assisted miniaturized matrix solid-phase dispersion and homogeneous liquid-liquid extraction for the determination of some organochlorinated pesticides in fish

In this study, ultrasonic assisted miniaturized matrix solid-phase dispersion (US-MMSPD) combined with homogeneous liquid–liquid extraction (HLLE) has been developed as a new method for the extraction of organochlorinated pesticides (OCPs) in fish prior to gas chromatography with electron capture detector (GC-ECD). In the proposed method, OCPs (heptachlor, aldrin, DDE, DDD, lindane and endrin) were first extracted from fish sample into acetonitrile by US-MMSPD procedure, and the extract was then used as consolute solvent in HLLE process. Optimal condition for US-MMSPD step was as follows: volume of acetonitrile, 1.5 mL; temperature of ultrasound, 40 °C; time of ultrasound, 10 min. For HLLE step, optimal results were obtained at the following conditions: volume of chloroform, 35 μL; volume of aqueous phase, 1.5 mL; volume of double distilled water, 0.5 mL; time of centrifuge, 10 min. Under the optimum conditions, the enrichment factors for the studied compounds were obtained in the range of 185–240, and the overall recoveries were ranged from 39.1% to 81.5%. The limits of detection were 0.4–1.2 ng g⁻¹ and the relative standard deviations for 20 ng g⁻¹ of the OCPs, varied from 3.2% to 8% (n = 4). Finally, the proposed method has been successfully applied to the analysis of the OCPs in real fish sample, and satisfactory results were obtained.     

Particle speciation during PEG–Fe<Subscript>3</Subscript>O<Subscript>4</Subscript> hybrid nanoparticle self-assembly on Si(Ti)O<Subscript>2</Subscript>

The kinetics of assembly of polyethylene glycol (PEG)-coated superparamagnetic Fe₃O₄ nanoparticles in aqueous suspension on planar Si(Ti)O₂ surfaces have been determined using high-resolution optical waveguide lightmode spectroscopy (OWLS). Analysis of the results revealed that the initially uniform population was spontaneously transformed into two types of particles with significantly different adsorption behaviour.     

Enhancing Photocatalytic Activity of Cu2O in Degradation of Sulphonic Acid-Based Dye

Russian Journal of Applied Chemistry - In the present investigation, we synthesized copper (I) oxide nanoparticles (NPs) by the coprecipitation method. The obtained materials were characterized by...     

Mild and efficient tetrahydropyranylation of alcohols and dehydropyranylation of THP ethers catalyzed by ferric perchlorate

A simple, mild and efficient method for tetrahydropyranylation and dehydropyranylation of alcohols in the presence of ferric perchlorate are described.     

Comparative performance of different urea coating materials for slow release

Approximately 70%of the applied urea fertilizer may be lost into the environment.This loss is due to leaching,decomposition and ammonium volatilization in soil,water and air.Through coating,the slow release technology can be used to reduce losses and to increase the fertilizer efficiency.Sulfur has been used as a coating material,but the coating cracks easily because of its friability,sometimes being peeled off from the urea surface.In this study,four types of materials,namely,gypsum,cement,sulfur and zeolite,were mixed and used as coating materials to search for the most effective and cheap coating materials.The primary reasons for selecting these materials were improving fruit quality and preventing plant diseases,providing a plant nutrient,increasing soil fertility and water retention.The materials were also selected based on their availability,processiblity and price.The effects of the coating materials,thickness,drying time,sieving and sealant on the crushing strength and dissolution rate of urea were investigated.Coated urea with the same proportion of gypsum-sulfur exhibited high crushing strength and lower dissolution rate.However,the performance was further enhanced by applying molten paraffin wax on the hot urea surface.SEM images demonstrated that the micro-structure of gypsum-sulfur coated urea after sieving resulted in a smoother coated layer.The efficiency of the coated urea was improved by26%using gypsum-sulfur（20%total coating）,3%paraffin wax and sieving the coating materials before application.