New chiral catalyst systems were developed for the reaction of carbon dioxide with propylene oxide (PO) at atmospheric pressure to generate enantiomerically enriched propylene carbonate (PC). The best selectivity was achieved with a Co(III)(salen)-trifluoroacetyl complex and bis(triphenylphosphoranylidene)ammonium fluoride (PPN+F-) as catalysts, affording PC in 40% yield and 83% ee (selectivity...

The influence of a standardized pollen extract (Cernitin) on the hepatic cytochrome P-450 system was studied in rats chronically exposed to an aerosol of ammonium fluoride. The content of cytochrome P-450 and cytochrome b5 and the activities of NADPH-cytochrome c reductase, aminophenazone N-demethylase, and aniline hydroxylase were determined. After 3 months the content of cytochrome b5 in the ...

diolefinic antibacterial laser dye namely 1,4-bis[2-(4-pyridyl) vinyl] benzene (4pvb)have been investigated electrochemically using cyclic voltammetry, chronoamperometry, convolution and deconvolution voltammetry combined with digital simulation techniques at a platinum electrode in 0.1 mol / l tetra butyl ammonium perchlorate (tbap) in  solvent 1,2-dichloroethane.  the diolefinic species were ...

an ultrasound-assisted surfactant-enhanced emulsification microextra- ction (uaseme) coupled with high performance liquid chromatography-diode array detection has been developed for the extraction and determination of thiopental in serum and urine samples. a simple microextraction method based on emulsification of organic extraction solvent in aqueous sample using an ionic surfactant and withou...

In recent years, there has been a growing interest in green solvents to dissolve and shape cellulose into microspheres. However, development of suitable for room temperature dissolution shaping spheres is very limited. this work, novel process fabricate microspheres presented. First, the effect ethanol-hydrochloric acid pulp pretreatment on solubility aqueous tetra-n‑butyl phosphonium hydroxide...

A robust nanogenerator based on poly(tert-butyl acrylate) (PtBA)-grafted polyvinylidene difluoride (PVDF) copolymers via dielectric constant control through an atom-transfer radical polymerization technique, which can markedly increase the output power, is demonstrated. The copolymer is mainly composed of α phases with enhanced dipole moments due to the π-bonding and polar characteristics of th...

The stannous alkoxides [Sn(OR)2] [R = i-Pr, t-Bu, C(Et)Me2, CHPh2, CPh3] have been synthesised by reaction of Sn(NR'2)2 with two equivalents of HOR [R' = Me, R = i-Pr; R' = SiMe3, R = t-Bu, C(Et)Me2, CHPh2, CPh3]. Single crystal X-ray diffraction analysis of the bis(diphenylmethoxide) (4) and bis(triphenylmethoxide) (5) species have shown them to comprise three-coordinate Sn(ii) centres through...