o‐Carboxybenzoylferrocene. Bioactivity and chemical Modifications

The antitumor activity of o‐carboxybenzoylferrocene sodium salt ( 1 ) was studied in vivo . Interaction between o‐carboxybenzoylferrocene ( 2 ) and N,N′‐carbonyldiimidazole in boiling methylene dichloride leads to 3‐(N‐imidazolyl)‐3‐ferrocenylisobenzofuran‐1(3H)‐one ( 5 ). The structure of compound 5 was established by X‐ray analysis. Aminolysis of compound 5 in toluene gave rise to ferrocenoylbenzamides ( 6a – d )–derivatives of dimethylamine, piperidine, pyrrolidine and morpholine. Copyright © 2008 John Wiley & Sons, Ltd.     

Cascade synthesis of pyrido[3,2-a]indolizines by reaction of Kröhnke–Mukaiyama salts with malononitrile dimer

An efficient protocol for the synthesis of highly functionalized 2-aminoindolizines and pyrido[3,2-a]indolizines has been achieved via the reaction of N-RC(O)CH₂-2-chloropyridinium bromides with 2-amino-1,1,3-tricyanopropene in the presence of Et₃N. The reaction of N-allyl-2-chloropyridinium bromide with 2-amino-1,1,3-tricyanopropene in the presence of Et₃N gives 3-[1-allylpyridin-2(1Н)-ylidene]-2-aminoprop-1-ene-1,1,3-tricarbonitrile, which could be cyclized to give [2-amino-(2-amino-3-vinylindolizin-1-yl)methylene]malononitrile upon treatment with KOH–DMF.     

Miniaturised flow-through PLM coupled with spectrophotometric detection for copper(II) speciation in fungicides†

Construction of a novel miniaturised Permeation Liquid Membrane (mPLM) set-up is described. A hydrophobic Celgard 2500 membrane with copper(II) carrier separates the source and receiving solutions flowing in the channels on two sides of the membrane. The set-up consists of two half-cells with channel width of 2?mm and depth variable between 100 and 500?µm made of poly(dimethylsiloxane) (PDMS) using a moulding technology. In contrast to most previous constructions, the new mPLM operates in full flow-through mode, in both source and receiving solutions. This allows for on-line and real-time coupling with the detection system, which significantly reduces the time of analysis. In the present set-up a UV/Vis spectrophotometric detection was applied for Cu(II) transport. For this purpose a composition of the receiving solution was optimised to allow for both free metal ion buffering, which is necessary for maintaining the driving force of the transport, and spectrophtometric detection. The applied UV/Vis detection method is linear in the range 2?×?10^?6?M – 4?×?10^?5?M (R ^2?=?0.996) with a detection limit of 10^?6 M in the volume of ca 350?µL (including the receiving channels, cuvette and tubing). The relative standard deviation does not exceed 5%. The transport capabilities of the mPLM set-up are demonstrated using four commercial copper-based fungicides: Nordox 75?WG, Miedzian 50?WP, Curzate 49.5?WP and Mag 50?WP.     

Thin mesoporous polyaniline films manifesting a water-promoted photovoltaic effect

Photovoltaic cells composed of thin mesoporous polyaniline films sandwiched between an indium-tin oxide anode and aluminium cathode have been fabricated. The cells show an increase in the photo-generated open-circuit voltage (V _oc) from 0.2 V to 0.6 V and stable-in-time V _oc generation following the addition of water containing highly hydrated ions, e.g. tap water.We explain the waterpromoted photo-voltaic effect by the polarity of the water environment. Theoretical calculations show that increasing the solvent polarity increases the energy of the electronic transition related to the measured V _oc. The stable-in-time V _oc generation could be explained by the increase in the lifetime of the excitons as well as by their more efficient dissociation in the interpenetrating network of polyaniline and water. The penetration of water into the mesoporous polyaniline films is promoted by the presence of highly hydrated ions.     

Procedure of determination of volatile trihalomethanes in human urine with pervaporation and gas chromatography

This work presents the development of a novel procedure for the determination of trihalomethanes (THMs) in human urine samples based on: (1) pervaporation (PV) of analytes from urine samples as a convenient analyte isolation/enrichment technique; (2) direct aqueous injection of the extracts onto the column of a gas chromatograph equipped with an electron capture detector (DAI-GC-ECD). Basic parameters of the new PV-DAI-GC-ECD procedure were evaluated. The calibration curves were linear in the concentration range examined. Intermediate precision of the procedure was good, at the same level of about 20% for all analytes. The method detection limits were below 0.10?µg?L^?1 for all analytes. The enrichment factors did not differ significantly for water and urine samples, indicating little or no matrix effects.     

Induction of Motion in a Synthetic Molecular Machine: Effect of Tuning the Driving Force

Rotaxane molecular shuttles were studied in which a tetralactam macrocyclic ring moves between a succinamide station and a second station in which the structure is varied. Station 2 in all cases is an aromatic imide, which is a poor hydrogen‐bond acceptor in the neutral form, but a strong one when reduced with one or two electrons. When the charge density on the hydrogen‐bond‐accepting carbonyl groups in station 2 is reduced by changing a naphthalimide into a naphthalene diimide radical anion, the shuttling rate changes only slightly. When station 2 is a pyromellitimide radical anion, however, the shuttling rate is significantly reduced. This implies that the shuttling rate is not only determined by the initial unbinding of the ring from the first station, as previously supposed. An alternative reaction mechanism is proposed in which the ring binds to both stations in the transition state.     

Electrochemistry of bismuth interlayers in (Bi2)m(Bi2Te3)n superlattice

Journal of Solid State Electrochemistry - Selective electrochemical transformations of bismuth interlayers in (Bi2)m(Bi2Te3)n superlattices can be of interest as a means of thermoelectric materials...     

Dynamic Calcium Metal–Organic Framework Acts as a Selective Organic Solvent Sponge

Herein, we present a Ca‐based metal–organic framework named AEPF‐1, which is an active and selective catalyst in olefin hydrogenation reactions. AEPF‐1 exhibits a phase transition upon desorption of guest molecules. This structural transformation takes place by a crystal to crystal transformation accompanied by the loss of single‐crystal integrity. Powder diffraction methods and computational studies were applied to determine the structure of the guest‐free phase. This work also presents data on the exceptional adsorption behavior of this material, which is shown to be capable of separating polar from nonpolar organic solvents, and is a good candidate for selective solvent adsorption under mild conditions.