Preparation of various xanthene derivatives over sulfonic acid functionalized imidazolium salts (SAFIS) as novel,highly efficient and reusable catalysts

In this work, some novel sulfonic acid functionalized imidazolium salts (SAFIS), as a new category of ionic liquids, are synthesized by eco-friendly and simple procedures, and used as highly efficient and reusable catalysts to promote the following one-pot multicomponent organic transformations under solvent-free conditions: (i) the synthesis of 14-aryl-14H-dibenzo[a,j]xanthenes from β-naphthol (2 eq.) and arylaldehydes (1 eq.), (ii) the preparation of tetrahydrobenzo[a]xanthene-11-ones from β-naphthol, arylaldehydes and dimedone, and (iii) the synthesis of 1,8-dioxo-octahydroxanthenes from dimedone (2 eq.) and aromatic aldehydes (1 eq.). Environmentally benign, simple methodologies, easy workup procedure, clean reaction, short reaction time, high yield and easy preparation of the catalysts are some advantages of this work.     

Chemically modified carbon paste electrode for determination of copper(II) by potentiometric method

The utility of carbon paste electrode modified with DTPT (3,4-dihydro-4,4,6-trimethyl-2(1H)-pyrimidine thione) for the potentiometric determination of Cu(II) in aqueous medium is demonstrated. The electrode exhibits linear response to Cu(II) over a wide concentration range (9.77x10(-7)-7.6x10(-2)) with Nernstian slope of 30+/-2 mV per decade. It has a response time of about 45 s and can be used for a period of two months with good reproducibility. The detection limit of this electrode was 7.0x10(-7) M. The proposed electrode shows a very good selectivity for Cu(II) over a wide variety of metal ions. This chemically modified carbon paste electrode was successfully used for the determination of Cu(II) in electronics waste sample solution.     

Probing the Dynamic Mechanism of Uncommon Allosteric Inhibitors Optimized to Enhance Drug Selectivity of SHP2 with Therapeutic Potential for Cancer Treatment

Applied Biochemistry and Biotechnology - There is currently considerable interest in SHP2 as a potential target for treatment of cancer. Mutation in SHP2, particularly the E76A mutation, has been...     

Synthesis and Characterization of Zinc Oxide Nano-particles by Solid State Chemical Reaction Method

Several important synthetic parameters such as precursor concentration, reaction time are found to determine the growth of ZnO nanostructures. These reaction parameters can be tuned to produce a variety size of nanostructures. In this work we show the importance of these parameters on the size of synthesized zinc oxide nano-powders. ZnO nanoparticles are synthesized by the solid-state reaction using ZnSO₄·7H₂O and NaOH as the reagents. In this method Zn(OH)₂ is the intermediate product of the reaction, we show that by adjusting the molar ratio of the reagents and grinding time, we can be removed this unwanted component in the final product so for obtaining pure ZnO nanostructures the calcinations process is not necessary, also we can tune the size of ZnO nanoparticles. XRD spectra of the nanoparticles demonstrate typical diffraction peaks of a well-crystalline Wurtzite ZnO structure transmission electron microscopic observations show that these nanoparticles are of hexagonal phase ZnO mostly in round shapes and he composition analysis by EDX indicate that final product is pure ZnO. In the optimum conditions by XRD analysis we see that the mean grain size of synthesized zinc oxide nano-particles is about 44 nm.     

Imidazole-functionalized magnetic Fe3O4 nanoparticles: an efficient,green, recyclable catalyst for one-pot Friedländer quinoline synthesis

Research on Chemical Intermediates - An efficient and cost-effective procedure for preparation of Fe3O4 nanoparticles and supported Brønsted acidic ionic liquid...     

A novel dicationic ionic liquid as a highly effectual and dual-functional catalyst for the synthesis of 3-methyl-4-arylmethylene-isoxazole-5(4H)-ones

Research on Chemical Intermediates - A novel dicationic ionic liquid, N,N,N′,N′-tetramethyl-N,N′-bis(sulfo)ethane-1,2-diaminium mesylate [TMBSED][OMs]2), has been produced, and...     

The formation of cyclopentenones and 3(2h)-furanones from acetylenic precursors

Acetylenic alcohols, obtained in high yield from condensations of 3,3-diethoxypropyne or 3,3-ethylenedioxybutyne with cyclic ketones, may be used as substrates for cyclopentenone annelation or spirofuranone synthesis.     

Simultaneous determination of antimony and bismuth by beta-correction spectrophotometry and an artificial neural network algorithm

Simultaneous determinations of antimony and bismuth were done by β-correction spectrophotometry and a feed forward neural network algorithm with back propagation of error. The sensitivity was improved using β-correction spectrophotometry. The determination of trace amounts of mixtures of Sb and Bi in various matrices (river, tap and industrial wastewater) were investigated by neural network and β-correction spectrophotometry using the complexes formed between pyrogallol red, Sb and Bi. The results showed that measurement is possible in the ranges of 0.05-5.0 and 0.2-3.2 μg ml⁻¹ for Sb(III) and Bi(III), respectively. The results also show very good agreement between true and predicted concentration values and have the ability to use in routine analysis.