Green Procedure for the Synthesis of Phthalazino[2,3‐b]phthalazine‐5,7,12,14‐tetraones

Different novel phthalazino[2,3‐b]phthalazine‐5,7,12,14‐tetraones were synthesized in a simple and environmentally benign method from the reaction of phthalic anhydrides with semicarbazide or thiosemicarbazide using montmorillonite K‐10 clay as solid heterogeneous acidic catalyst and microwaves under solvent‐free conditions in good yields and short reaction times. Products were characterized by the elemental analysis, IR, NMR, and mass spectrometry.     

Study of complexation process between 4′-nitrobenzo-15-crown-5 and yttrium(III) cation in binary mixed non-aqueous solvents using conductometric method

The complexation reaction of macrocyclic ligand (4??-nitrobenzo-15C5) with Y³⁺ cation was studied in acetonitrile-methanol (AN-MeOH), acetonitrile-ethanol (AN-EtOH), acetonitrile-dimethylformamide (AN-DMF) and ethylacetate-methanol (EtOAc-MeOH) binary mixtures at different temperatures using conductometry method. The conductivity data show that in all solvent systems, the stoichiometry of the complex formed between 4??-nitrobenzo-15C5 and Y³⁺ cation is 1: 1 (ML). The stability order of (4??-nitrobenzo-15C5). Y³⁺ complex in pure non-aqueous solvents at 25°C was found to be: EtOAc > EtOH > AN ?? DMF > MeOH, and in the case of most compositions of the binary mixed solvents at 25°C it was: AN??MeOH ?? AN-EtOH > AN-DMF > EtOAc-MeOH. But the results indicate that the sequence of the stability of the complex in the binary mixed solutions changes with temperature. A non-linear behavior was observed for changes of logK _f of (4??-nitrobenzo-15C5 · Y³⁺) complex versus the composition of the binary mixed solvents, which was explained in terms of solvent-solvent interactions and also the hetero-selective solvation of the species involved in the complexation reaction. The values of thermodynamic parameters (??H _c ^? and ??S _c ^? ) for formation of the complex were obtained from temperature dependent of the stability constant using the van??t Hoff plots. The results represent that in most cases, the complex is both enthalpy and entropy stabilized and the values and also the sign of thermodynamic parameters are influenced by the nature and composition of the mixed solvents.     

Green and mild laccase-catalyzed aerobic oxidative coupling of benzenediol derivatives with various sodium benzenesulfinates

The oxidative coupling reaction between hydroquinone or catechols and various sodium benzenesulfinates was investigated using the laccase from Trametes versicolor, in the presence of O₂ in a phosphate buffer solution at room temperature to afford sulfonyl benzenediols in 75–95% yield.     

Synthesis and characterization of novel optically active poly(amide-imide)s and poly(ester-imide)s containing calix[4]arene and amino acid units with binding ability towards alkali metal and toxic heavy metal cations

<正>A novel calix[4]arene derivative 2 with amino functional groups at the lower rim was first prepared via introduction of nitro functional groups and amination of the dinitro derivative of calix[4]arene.The optically active monomers were synthesized by dehydration of L-leucine(and L-isoleucine) and 3,3',4,4'-benzophenonetetracarboxylic- 3,3',4,4'-dianhydride(3) followed by reaction with thionyl chloride to form 5a and 5b.Two methods,polymerization under microwave irradiation and solution polymerization in CH_2Cl_2/TEA,were then employed to carry out the condensation polymerization of 2 with the optically active monomers 5a and 5b,respectively.The polymerization conditions affected the kind of resulting polymers,poly(amide-imide)s(PAIs) 6a and 6b and poly(ester-imide)s(PEIs) 6a' and 6b' were obtained selectively in good yields and moderate inherent viscosities.Sorption-extraction experiments were carried out using cram picrate extraction method and verified good binding ability of the resulting calixarene-based polymers towards silver,alkali metal and toxic heavy metal cations.Also thermogravimetric analysis indicated that the resulting PAIs and PEIs were thermally stable.     

ZnO thin film characterization by X-ray reflectivity optimization using genetic algorithm and Fourier transformation

Zinc oxide (ZnO) thin film was fabricated by sol-gel spin coating method on glass substrate. X-ray reflectivity (XRR) and its optimization have been used for characterization and extracting physical parameters of the film. Genetic algorithm (GA) has been applied for this optimization process. The model independent information was needed to establish data analyzing process for X-ray reflectivity before optimization process. Independent information was exploited from Fourier transform of Fresnel reflectivity normalized X-ray reflectivity. This Fourier transformation (Auto Correlation Function) yields thickness of each coated layer on substrate. This information is a keynote for constructing optimization process. Specular X-ray reflectivity optimization yields structural parameters such as thickness, roughness of surface and interface and electron density profile of the film. Acceptable agreement exists between results obtained from Fourier transformation and X-ray reflectivity fitting.     

Fabrication and characterization of copper nanoparticles using thermal reduction: The effect of nonionic surfactants on size and yield of nanoparticles

Thermal reduction has been applied to the preparation of copper nanoparticles (Cu-NPs) using three kinds of nonionic surfactants (Triton X-100, Tween-80, and dodecylamine). The Cu-NPs were formed by decomposition of copper(II) oxalate in presence of triphenylphosphine. The effect of the surfactants on the formation of the Cu-NPs was studied via X-ray diffraction, scanning electron microscopy, energy dispersive analysis of X-rays, transmission electron microscopy, thermogravimetric differential thermal analyses, and Fourier transform infra-red spectroscopy. It is shown that the Cu-NPs have an fcc crystal structure. Depending on the surfactant used, Cu-NPs with diameters between 8 and 20 nm can be prepared. The smallest Cu-NPs (8 nm) were formed in the presence of micelles of dodecylamine (yield 49%), while the largest particles (20 nm) were obtained with Triton X-100 (yield 99%). The use of Triton X-100 results in the highest yield and most uniform Cu-NPs.