Studies on the mixed-ligand complexes of copper(II) with gallic acid and pyridine carboxylic acids and their benzologues

Summary The ternary complex formation of copper(II) with gallic acid (gal) and 2-hydroxy nicotinic acid (hyna), 2-mercapto nicotinic acid (mena), salicylic acid (sa) or thiosalicylic acid (tsa) as a second ligand in a 1:1:1 molar ratio has been investigated in 40% (v/v) ethanol using spectrophotometric andpH titration methods. The solution equilibria of the ternary systems have been determined and the stability constants of the mixed complexes has been evaluated. Considering all parameters, the Cu-gal-sa ternary system was proved as a suitable, rapid, and sensitive spectrophotometric indicator for determining traces of copper.The ternary system containingsa obeysBeer's law up to 3.4 µg·ml^–1 copper. The optimum range for the determination of copper (Ringbom) atpH 6.0 ranges from 0.63 to 1.74 µg·ml^–1 of copper. The molar absorptivity of the ternary complex is 1.3×10⁴l·mol^–1·cm^–1.

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Untersuchungen anmixed-ligand — Komplexen von Kupfer(II) mit 3,4,5-Trihydroxybenzoesäure und Pyridincarbonsäuren und ihren C-Homologen

Zusammenfassung Die Bildung ternärer Komplexe von Kupfer(II) mit 3,4,5-Trihydroxybenzoesäure (gal) und 2-Hydroxynicotinsäure (hyna), 2-Mercaptonicotinsäure (mena), Salicylsäure (sa) oder Thiosalicylsäure (tsa) in einem molaren Verhältnis von 1:1:1 wurde mittels spektrophotometrischer und potentiometrischer Methoden in 40% (v/v) Ethanol untersucht. Die Lösungsgleichgewichte der termären Systeme und die Stabilitätskonstanten der gemischten Komplexe wurden bestimmt. Unter Berücksichtigung aller Parameter erwies sich das termäre System Cu-gal-sa als geeigneter schneller und empfindlicher Indikator zur Spurenanalyse von Kupfer.Dassa enthaltende ternäre System gehorcht demBeerschen Gesetz bis zu einer Kupferkonzentration von 3.4 µg·ml^–1. Der optimale Bereich zur Bestimmung von Kupfer (Ringbom) beipH 6.0 erstreckt sich von 0.63 bis 1.74 µg Cu pro ml. Die molare Extinktion des ternären Komplexes beträgt 1.3×10⁴l·mol·cm^–1.

     

Diminishing the Gap Between GC-Selective and Universal Detection by Capped Pd Nanoparticles

A simple Pd²⁺ ligand exchanger was prepared and applied for isolation of aromatic heterocyclic sulfur compounds (S-PAHs) from petroleum condensate oil. The ligand exhibited excellent isolation efficiency and selectivity towards S-PAHs. The chromatograms of pre-isolated S-PAHs recorded by universal flame ionization (FID) and mass spectrum (MS) detections are similar to selective sulfur atomic emission detector chromatograms, indicated from traces or absence of hydrocarbons in FID and MS chromatograms. Nitrogen adsorption, electronic microscope, and X-ray diffraction techniques were employed to confirm the formation of capped Pd²⁺ nanoparticle dispersion within the silica framework. The results obtained revealed that Pd²⁺ ions exist as dispersed capped nanoparticles sized between 69 and 79 nm that can be rationalized for their enhanced isolation selectivity towards the S-PAH fraction of petroleum condensate oil.

     

Novel Synthesis of some Spiro Heterocycles Derived from 3-Hydroxy-3(2-Oxocyclohexyl)-Indolin-2-One

The reaction of 3-hydroxy-3(2-oxocyclohexyl)indolin-2-one 1 with some active methylene, bidentates, phenylisocyanate, phenylisothiocyanate, carbon disulfide, benzaldehyde, ketoketene S,S-acetal, cyanoketene S,S-acetal, active halo compounds or benzylidenemalononitrile affords a series of new spiro heterocyclic systems.     

Accelerating the calculations of binary detour phase method by integrating both CUDA and Matlab programming for GPU's parallel computations

The availability of state of art GPGPU cards can play a promising role in accelerating the calculations of computer generated holograms (CGH) where one of the main problems of generating such holograms is the need for massive amount of calculations. Both CUDA and Matlab can be used alone to fulfill this purpose but using both at the same time gives a number of benefits. This paper is dedicated to present a performance study of applying Fermi-Architecture CUDA-enabled GPGPU card for speeding up the calculations of binary detour phase holograms using both Matlab and CUDA programming.     

A facile approach for synthesis of thiazines-, thiazoles- and triazoles-annulated 6-styryl-2-thiouracil derivative

Journal of the Iranian Chemical Society - Utility of 4-oxo-6-styryl-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carbonitrile 1 in synthesis of a new series of fused pyrimidines was described....     

Buprofezin dissipation and safety assessment in open field cabbage and cauliflower using GC/ITMS employing an analyte protectant

An analytical method for the determination of buprofezin residues in cabbage and cauliflower was developed and validated using gas chromatography with ion trap mass spectrometry. The analyte protectant d ‐sorbitol was used at a concentration level of 0.5 mg mL^?1 in acetonitrile instead of in matrix for constructing the calibration curves of the buprofezin standard. The average recoveries ranged from 91.3 to 96.8%, with an RSD of ≤2.7%. The limits of detection and quantitation of the method in cabbage and cauliflower were 1.3, 1.7 and 4.3, 6.2 μg kg^?1, respectively. The residual levels and dissipation kinetics of buprofezin 25% wettabe powder in cabbage and cauliflower cultivated under open field conditions was investigated at the single (T1) and double (T2) recommended rates of application. Half‐life periods were found to be 1.73 and 2.1 days in cabbage, whereas in cauliflower, these values were 1.85 and 2.36 days at T1 and T2, respectively. Based on the dissipation study, and the maximum residue limit value of 0.05 mg kg^?1, the proposed pre‐harvest interval of buprofezin in cabbage was 3–6 days and that in cauliflower was 4–10 days. The results showed that buprofezin is safe for application at both recommended application rates.     

Synthesis of PAN/ferrocyanide composite incorporated with cetrimonium bromide and its employment as a bifunctional adsorbent for coremoval of Cs+ and HCrO4− from aqueous solutions

Polyacrylonitrile/ferrocyanide composite incorporated with cetrimonium bromide (PFICB) was synthesized and evaluated as a novel bifunctional adsorbent for coremoval of Cs⁺ and HCrO₄^?. Results of the reaction time effect showed that adsorption of Cs⁺ and HCrO₄^? onto PFICB were rapid processes. The effect of the solution pH in the range 2.5–10 revealed that PFICB had the ability to simultaneously remove Cs⁺ and HCrO₄^?. The maximum adsorption capacity of PFICB was found to be 41.79 mg/g for Cs⁺ and 19.39 mg/g for HCrO₄^?. These values were compared with those reported in literature using other adsorbents.

     

Synthesis and Antibacterial Activity of Some New S-Triazole Derivatives

Abstract

Alkylation of 4-anilino-5-phenyl-4H-1,2,4-triazole-3-thiol (1) with some halo compounds yielded the corresponding sulfides 2a–f. Some sulfides 2e,f were cyclized to give triazolothiadiazines 3 and 4. Triazolothiadiazoles 5 and 6 were prepared through the reaction of compound 1 with carbon disulfide or ethyl orthoformate, respectively. Treatment of compound 1 with ethyl chloroformate or phenyl isothiocyanate yielded triazolo-thiadiazole and triazole 9 and 10, respectively. Reaction of compound 1 with Lawesson's reagent gave triazolothiadiazaphosphole derivative 11. Also, compound 1 underwent cyclocondensation reactions with some bidentate reagents to give triazolothiazines 4, 12, and 13. Triazolo-thiazepines and triaziepine 14–16 were synthesized via the reaction of compound 1 with β-ketoesters or ethyl cyanoacetate. Tricyclic systems 19 and 20 were prepared through the reaction of compound 4 with the appropriate reagent. Some synthesized compounds were tested for antibacterial activity.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

Characterization of the Charge Transfer Complex from Furan and Maleic Anhydride and the Alternating Copolymer

A previously unreported copolymer between furan and maleic anhydride was readily obtained by free radical initiation of benzene solutions of the comonomers. The product copolymers exhibit remarkably uniform composition regardless of monomer feed ratios. A donor-acceptor complex was suspected to account for the 1:1 alternating sequence of the monomers in the product. The complex was easily detected and partially characterized, although its exact role in the mechanism is uncertain.     

Synthesis and characterization of MFe2O4 sulfur nanoadsorbents

Nanoparticles of ferrites (Fe₃O₄, NiFe₂O₄, CuFe₂O₄, and MnFe₂O₄) were prepared by a reverse (water/oil) microemulsion method. The microemulsion system consisted of cetyltrimethylammonium bromide, 1-butanol, cyclohexane, and a metal salt solution. The procedure was carried out using aqueous ammonia as the coprecipitating agent. Nanosized particles were characterized by thermal analysis, X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, and pyridine adsorption. The NiFe₂O₄ sample exhibited narrow mesoporous pore size distribution and high surface area ≈233 m²/g. It achieved good adsorption activity towards the dibenzothiophene (DBT) compound (166.3 μmol/g of DBT adsorbent). The structural properties obtained were very interesting for potential applications in the desulfurization process in petroleum refining.