A novel optical sensor for uranium determination

A metal ion indicator, Alizarin Red S, was tested for its potential use in uranium selective optode membrane. The water-soluble indicator was lipophilized in the form of an ion pair with tetraoctylammonium bromide, and subsequently immobilized on a triacetyl cellulose membrane. The membrane responds to uranium ions, giving a color change from yellow to violet in acetate buffer pH 5. This optode has a linear range of (1.70-18.7) × 10⁻⁵ M of UO₂²⁺ ions with a limit of detection of 5 × 10⁻⁶ M. The response time of optode was within 6 min depending on the concentration of UO₂²⁺ ions. The sensor can readily be regenerated with hydrochloric acid solution (0.01 M). The optode is fully reversible.     

Screening of hepatitis B virus DNA in the serum sample by a new sensitive electrochemical genosensor-based Pd-Al LDH substrate

Journal of Solid State Electrochemistry - Screening for hepatitis B is one of the most severe liver virus infections in the world, and due to the effect of early detection and treatment of...     

A facile and effective procedure for synthesis of polyfunctionalized pyrrolines from simultaneously stirring of carbon disulfide,aniline, arylglyoxals and <Emphasis Type="Italic">β</Emphasis>-enaminocarbonyls

An efficient one-pot synthesis of 2H-pyrroline derivatives by a four-component reaction between carbon disulfide, aniline, arylglyoxals and β-enaminocarbonyls in acetonitrile at room temperature under mild reaction conditions is reported. The addition reaction has been done to access broad range of 5-hydroxy-4-phenylcarbamodithioate 2-H pyrroline derivatives after about 6 h stirring. All reactions were performed in acetonitrile at room temperature. Reactions are clean, and products were isolated by simple filtration.     

How OH and O– groups affect electronic structure of meta-substituted and para-substituted phenols and phenolates

Structural Chemistry - An application of two independent quantum chemistry-based concepts, a substituent effect stabilization energy (SESE) and a charge of the substituent active region (cSAR), for...     

Pd(II) salen complex covalently anchored to multi‐walled carbon nanotubes as a heterogeneous and reusable precatalyst for Mizoroki–Heck and Hiyama cross‐coupling reactions

A Pd(II) salen complex anchored to multi‐walled carbon nanotubes showed excellent catalytic activity and stability for the Mizoroki–Heck and Hiyama cross‐couplings of aryl halides with olefins and phenylsiloxanes. Furthermore, the heterogeneous catalyst could be reused up to four times with the catalytic activity being recovered easily after simple manipulations. Copyright © 2014 John Wiley & Sons, Ltd.     

Highly sensitive electrochemical detection of dopamine and uric acid on a novel carbon nanotube-modified ionic liquid-nanozeolite paste electrode

A novel biosensor has been constructed by incorporating modified nanosized natural zeolite and 3-hydroxypropanaminium acetate (HPAA) as a novel room temperature ionic liquid, supported on multiwalled carbon nanotube (MWCNTs) and employed for the simultaneous determination of dopamine (DA) and uric acid (UA). A detailed investigation by transmission electron microscopy and electrochemistry is performed in order to elucidate the preparation process and properties of the composites. The voltammetric studies using the modified carbon paste electrode show two well-resolved anodic peaks for DA and UA with a potential difference of 160 mV, revealing the possibility of the simultaneous electrochemical detection of these compounds. The modified carbon paste electrode shows good conductivity, stability, and extraction effect due to the synergic action of HPAA, MWCNTs, and iron ion-doped natrolite zeolite. Under optimized conditions, the peak currents are linear from 8.12?×?10^?7 to 3.01?×?10^?4?mol?L^?1 and from 9.31?×?10^?7 to 3.36?×?10^?4?mol?L^?1 with detection limits of 1.16?×?10^?7 and 1.33?×?10^?7?mol?L^?1 for DA and UA using the differential pulse voltammetric method, respectively. Finally, the modified carbon paste electrode proved to have good sensitivity and stability and is successfully applied for the simultaneous determination of DA and UA in human blood serum and urine samples.     

The New Antibacterial Agents Based on the Fused Aromatic Heterocyclic Compounds: Design,Synthesis, and Antibacterial Activity

Russian Journal of General Chemistry - In this study, the reaction of 1-alkyl-5-nitro-1H-benzoimidazoles and 1-alkyl-5-nitro-1H-indazoles with benzofuran and benzothiophen derivatives has led to...     

Synthesis and Crystal Structure of μ-oxo-bis[(octaethyloxoporphinato)iron(III)] Tetrafluoroborate

Exposure of dichloromethane solution of [OEOPFe(BF₄)], where OEOP is the monoanion of octaethyloxoporphyrin, to dioxygen results in its transformation into the μ-oxo bridged compound, [(OEOPFe)₂O)](BF₄)₂. The molecular structure of the title compound, [(OEOPFe)₂O](BF₄)₂, was determined by single-crystal X-ray diffraction. It contains a binuclear centrosymmetric [(OEOPFe)₂O]²⁺ cation (the bridging O atom lies on an inversion centre) and two tetrafluoroborate anions. The Fe atom is five-coordinate to four N atoms of the porphyrin ring and to one bridging O atom. The compound is characterized by an average Fe–N bond length of 2.064 Å. The Fe–O bond distance is 1.7665(11) Å and the Fe–O–Fe bond angle is 180.0° and the two porphyrin rings are parallel. Crystal data: crystal system, monoclinic, a = 8.867(3), b = 26.104(9), c = 15.748(6) Å, β = 105.40(3)°, space group, P2₁/c, V = 3514(2) Å³, Z = 2.     

Conjugation paths in monosubstituted 1,2- and 2,3-naphthoquinones

Optimization of monosubstituted (X = NO, NO(2), CN, CHO, Me, OMe, OH, NH(2), NHMe, and N(Me)(2)) derivatives of 1,2- and 2,3-naphthoquinone by use of B3LYP with the 6-311+G** basis set applying the GAUSSIAN03 program allowed us to analyze the character of interactions between the substituents and the carbonyl groups. It is shown that only one of two carbonyl groups exhibited substantial substituent effect evidenced by regression of the CO bond length and delocalization index, DI(CO) on the Hammett substituent constants, σ(p), with a very high correlation coefficient, whereas the other one did not depend in any substantial way on σ(p). Dependences of conjugation path built up of bonds between substituent and oxygen atoms of carbonyl groups on σ(p), give more acceptable correlations if the number of bonds in the path is even than in cases when they are odd.