A New Protonated form of Porphyrins in Solutions

The H-associate as a new protonated form of metalloporphyrins in strong acid media has been obtained and a qualitative reaction for its determination has been found; the properties and structure of a protonated form have been analyzed by spectral methods and quantum-chemical calculations.     

Bismuth nanoparticles electrooxidation: theory and experiment

The article presents the findings of microscopic and electrochemical studies of electrooxidation of bismuth particle of varying sizes. Bismuth particles were immobilized on the surface of indifferent carbon containing screen-printed electrodes. The calculations and experimental studies demonstrated that the transition from macroparticles to nanoparticles caused a shift of the maximum current potential of bismuth oxidation into the area with more negative potentials. A positive correlation between experimental and calculated data confirms once again a relevant application of the earlier proposed mathematical model and the possible use of the shift of the maximum current potential of electrooxidation to describe electrochemical activity and energy properties of metal nanoparticles.

     

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.