A molecularly imprinted polymer as the sorptive phase immobilized in a rotating disk extraction device for the determination of diclofenac and mefenamic acid in wastewater

The microextraction of diclofenac and mefenamic acid from water samples was performed by using rotating disk sorptive extraction (RDSE) with molecularly imprinted polymer (MIP) as the sorptive phase. The MIP was synthesized from the monomer 1-vinylimidazol (VI) together with the cross-linker divinylbenzene (DVB) using diphenylamine as the template molecule. Scanning electron microscopy (SEM) analyses of the MIP revealed clusters of spherical particles having a narrow size distribution, with diameters of approximately 1 μm.     

Sugli integrali multipli in generale,e su quelli che valgono per la rappresentazione analitica delle funzioni di più variabili reali

Rendiconti del Circolo Matematico di Palermo Series 1 -     

β-Nitro derivatives of iron corrolates

Two different methods for the regioselective nitration of different meso-triarylcorroles leading to the corresponding β-substituted nitrocorrole iron complexes have been developed. A two-step procedure affords three Fe(III) nitrosyl products-the unsubstituted corrole, the 3-nitrocorrole, and the 3,17-dinitrocorrole. In contrast, a one-pot synthetic approach drives the reaction almost exclusively to formation of the iron nitrosyl 3,17-dinitrocorrole. Electron-releasing substituents on the meso-aryl groups of the triarylcorroles induce higher yields and longer reaction times than what is observed for the synthesis of similar triarylcorroles with electron-withdrawing functionalities, and these results can be confidently attributed to the facile formation and stabilization of an intermediate iron corrole π-cation radical. Electron-withdrawing substituents on the meso-aryl groups of triarylcorrole also seem to labilize the axial nitrosyl group which, in the case of the pentafluorophenylcorrole derivative, results in the direct formation of a disubstituted iron μ-oxo dimer complex. The influence of meso-aryl substituents on the progress and products of the nitration reaction was investigated. In addition, to elucidate the most important factors which influence the redox reactivity of these different iron nitrosyl complexes, selected compounds were examined by cyclic voltammetry and thin-layer UV-visible or FTIR spectroelectrochemistry in CH(2)Cl(2).     

Dip and wait: a facile route to nanostructured porphyrin films for QCM functionalization

A facile and straightforward way to deposit nanostructured porphyrin films onto quartz surfaces is presented. The particular peripheral functionalization on the macrocycle is exploited to drive the formation of aggregates in solution, which then spontaneously deposit as ordered solid layers. Film deposition is then achieved by simple dipping the quartz slide into a solution containing porphyrin aggregates and waiting the formation of the related thin films. QCMs covered with different metalloporphyrin derivatives have been exposed to some model VOCs, showing in general good performances especially in all the cases where film morphology is fundamental for sensing interactions.     

Supramolecular Chirality in Solvent‐Promoted Aggregation of Amphiphilic Porphyrin Derivatives: Kinetic Studies and Comparison between Solution Behavior and Solid‐State Morphology by AFM Topography

The solvent‐promoted aggregation behavior of some amphiphilic porphyrin derivatives bearing chiral functionality in the form of a charged L ‐proline group has been investigated by UV/Vis, resonance light scattering, fluorescence and circular dichroism spectroscopy. The investigated macrocycles give rise to aggregates featuring supramolecular chirality with high ellipticity. Kinetic studies reveal peculiar differences in the fashion of aggregation, depending on the intimate nature of the chiral functionality, namely, cationic (nitrogen‐quaternized L ‐proline, 3H₂ ) or anionic (carboxylate residue, 6H₂ ) group. Formation of anionic 6H₂ aggregates shows a diffusion‐limited kinetic behavior. AFM topography studies show formation of tighter globular structures. On the other hand, the corresponding 3H₂ aggregates are formed by a cooperative, fractal‐type decay, and appear as long‐fibrous, looser structures. In the templated aggregation of 3H₂ over preformed 6H₂ aggregates, AFM images show formation of globular structures with reduced sizes, as a likely consequence of shorter interchromophore distances, due to favorable Coulombic interactions. The results obtained show an interesting parallelism between the solution behavior and the solid‐state aggregate structures, corroborating the sergeant–soldier effect observed in the templated aggregation. The results presented give important insights for understanding the complex mechanisms involved in these issues, which are of key importance for the development of chiral supramolecular materials and stereoselective sensors and devices.     

Erkennung eines Alkoholgehaltes in Aether

Ohne Zusammenfassung     

Nitration of iron corrolates: further evidence for non-innocence of the corrole ligand

Mono- and di-substituted β-nitro derivatives have been obtained from the reaction of ttcorrFeCl with sodium nitrite in refluxing DMF. This result is unprecedented for iron corrolates and further evidences the non-innocent character of the corrole ligand.