Synthesis,characterization, crystal structure and catalytic property of [Cu(SalAHE)2] (SalAHE = salicylaldehydeimine-1-hydroxyethane) complex for the oxidation of 3,5-di-tert-butylcatechol

The crystal structure, spectroscopic properties and catalytic property of the copper(II) complex, prepared by the reaction between copper(II) diacetate with the bidentate Schiff base, SalAHE (SalAHE = salicylaldehydeimine-1-hydroxyethane), are reported. This complex is able to oxidize 3,5-di-tert-butylcatechol to the respective o-quinone. The oxidation reaction was studied in CH₃CN with molecular oxygen at 0, 5, 15 and 25 °C. The progress of the catalytic reaction was followed by gas chromatographic analyses (GC).     

Influence of pH on the degradation 4-chlorophenol by gamma radiocatalysis using SiO2, Al2O3 and TiO2

Advanced oxidation process is a technology used in detoxification of residual water containing organic pollutants in small and medium scales. Radiocatalysis is a process that combines photocatalysis and radiolysis. An important experimental parameter in radiocatalysis is the pH because it influences the electrochemical system by modifying the electric charge on the surface of materials. This effect was investigated in the radiocatalytic degradation of 4-chlorophenol using titanium, silicium, and aluminum oxides. It was found that the degradation of 4-chlorophenol is enhanced at pH between 3 and 7.     

Functionalization of carbon nanofibers (CNFs) through atom transfer radical polymerization for the preparation of poly(tert‐butyl acrylate)/CNF materials: Spectroscopic,thermal, morphological,and physical characterizations

Vapor‐grown carbon nanofibers (CNFs) were oxidized and functionalized for atom transfer radical polymerization (ATRP) of tert‐butyl acrylate (t‐BA) from the surface of the CNFs. The materials were characterized by solubility tests, Fourier‐transform infrared (FTIR) spectroscopy, Raman spectroscopy, thermogravimetric analysis (TGA), X‐ray diffraction (XRD), and scanning electron microscopy. The FTIR and electron microscopy results suggest that ATRP process was successfully used to graft poly(tert‐butyl acrylate) (poly(t‐BA)) chains from the surface of the fibers. Raman results strongly indicate the partial degradation of the graphitic layer of CNFs because of the chemical treatments. TGA results suggest that the presence of poly(t‐BA) leads to a decrease of the initial degradation temperature of the fibers. XRD and electron microscopy results indicate that the microstructure of fibers was not destroyed because of the oxidation and functionalization processes. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 3326–3335, 2008     

Application of flavonoids – quercetin and rutin – as new matrices for matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometric analysis of Pt(II) and Pd(II) complexes

Attempts are being made to overcome the resistance of tumour cells to platinum (Pt) drugs by the synthesis of new generations of Pt complexes, and it is important to find appropriate and simple methods for the characterization of those novel complexes. The additional applicability of such a method for the analysis of the interactions of metal complexes with biomolecules would be advantageous. Matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOFMS) seems to possess the capability to become this method of choice, since it could be applied to low‐mass complexes as well as for the analysis of large biomolecules. In this work the applicability of flavonoids – quercetin and rutin – as matrices for MALDI‐TOFMS analysis of dichlorido(ethylendiamine)platinum(II) ([PtCl₂(en)]), dichlorido(diaminocyclohexane)platinum(II) ([PtCl₂(dach)]) and chloride (diethylenetriamine) palladium(II) chloride ([PdCl(dien)]Cl) complexes is demonstrated. Spectra of Pt(II) and Pd(II) complexes recorded in the presence of quercetin and rutin are rather simple: Pt(II) complexes generate [M+Na]⁺ or [M+K]⁺ions, whereas the investigated Pd(II) complex gives ions generated by the loss of one Cl^? or HCl. Flavonoids give a relatively small number of well‐defined ions in the low‐mass region (at m/z 303.3 for quercetin and m/z 633.5 for rutin). Quercetin and rutin can be applied in much lower concentrations than other common MALDI matrices and require rather low laser intensity. We speculate that flavonoids stabilize the structures of the metal complexes and that they may be useful for the analysis of other biologically active metal complexes, thus implying their broader applicability. Copyright © 2009 John Wiley & Sons, Ltd.     

Effect of Temperature on Thermophysical Properties of Ethanol + Aliphatic Alcohols (C<Subscript>4</Subscript>–C<Subscript>5</Subscript>) Mixtures

Summary. Speeds of sound, densities, and refractive indices of the binary mixtures containing ethanol+(2-methyl-1-propanol, 2-methyl-1-butanol, 1-pentanol, or 3-methyl-1-butanol) were measured at 288.15 ≤ T/K ≤ 323.15 and atmospheric condition in the whole compositional range. The effect of temperature was analyzed by several chemical terms.     

Separation of lanthanum,cerium and samarium from uranium samples

The radiation reduction yield of Fe³⁺ in complexes with various ligands (Cl^–, SO ₄ ^2– , CN^–) in methanol-water solutions has been studied. The effect of the dose, pH, scavenger concentration and matrix composition on the reduction, yield of Fe³⁺ in the above complexes and in Fe(acac)₃ was determined. Studies of methanol-water glasses (91) provided some interesting observations as to the effectiveness of scavenging the electrons by various ferric compounds. The effectiveness of scavenging decreases in the series Cl^–>SO ₄ ^2– >CN^–. As opposed to Co(acac)₃, Fe(acac)₃ appeared to be an ineffective scavenger.     

The reaction of cyclohexyl radicals with carbon tetrachloride

The photolysis of azocyclohexane, carbon tetrachloride, and cyclohexane at 360 nm has been investigated over a wide temperature range. At moderate temperatures a chain reaction ensues from which the following approximate rate constants could be determined assuming 2CCl₃. → C₂Cl₆, k₅ = 10^9.7 (303–673K): The really striking feature of the results is that they show that termination in bicyclohexyl [reaction (7)] is extremely slow: The root-mean-square rule for estimating the cross-combination rate is also followed. The photolysis of carbon tetrachloride and cyclohexane at 250 nm has also been investigated. The reaction is complicated by the occurrence of two concurrent photolytic processes, the main one yielding trichloromethyl radicals and chlorine atoms, and the subsidiary one yielding dichlorocarbene and molecular chlorine. Nonetheless the results from this reaction can be interpreted in the medium temperature range 360–430K, where long chains are present, in terms of the rate constants derived from the azocyclohexane system.     

The revised structure of mortonin

The structure 1 previously proposed tor mortonin, is revised to 2 based on spectroscopic and chemical evidence, and on biogenetic considerations.