A Novel Fluorimetric Bulk Optode Membrane Based on NOS Tridentate Schiff Base for Selective Optical Sensing of Al<Superscript>3+</Superscript> Ions

A novel fluorimetric optode has been developed for the highly selective and sensitive for the determination of ultra trace amounts of Al³⁺ ions. The proposed fluorescent optode is based on the incorporation of a simple and effective fluorescent sensor tridentate NOS Schiff base N-(2-hydroxynaphthylidene)-2-aminothiophenol (H₂L) in a plasticized PVC containing KTpClPB as a lipophilic anionic additive. H₂L was synthesized by a facile one-step Schiff base reaction. The plasticized PVC-membrane displays a calibration response for Al³⁺ ions over a wide concentration range from 1.0 × 10^?9 to 4.4 × 10^?3 mol/L. The fluorescence signal of the optode membrane can be easily recovered by immersion in 0.01 M EDTA. In addition to high stability and reproducibility, the sensor shows a unique selectivity towards Al³⁺ ion with respect to common co-existing cations, particularly Ga³⁺and In³⁺. The proposed optode was applied successfully for determination of Al³⁺ in some real samples, including bottled drinking waters, bottled mineral waters and soft drinks.     

From the discovery of sodiumoxyorganoalkoxysilanes to the organosilicon dendrimers and back

Upon being discovered 20 years ago, sodiumoxyorganoalkoxysilanes became the key to the world of organoelement dendrimers. Even considering the great variety of objects that had appeared in this area during the last 20 years, the organosilicon dendrimers are still one of the most actual objects in this class. Above all, this is fair concerning the carbosilane systems. The high reactivity of the functional groups, the well controlled chemistry of their transformations, and the inertness of the molecular skeleton are the reason for making these systems highly actual in two main regards: as model objects for the deep research of the dendrimers' properties and as polyfunctional matrixes for numerous derivatives. In this review, we were mainly focusing on the importance of the former part. In the conclusion, we showed the motivation for further development of this area both in regard of synthesis of new carbosilane systems and further development of siloxane dendrimers. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 4935–4948, 2008     

Surfactant and polymer-free electrochemical micropatterning of carboxylated multi-walled carbon nanotubes on indium tin oxide electrodes

We present a facile micropatterning method that is based on the electrochemically induced deposition of carboxylated multi-walled carbon nanotubes on an indium tin oxide electrode without using surfactants or polymers.     

Synthesis of 3-hydroxy-1-alkenylboronates via phosphine stabilized borylzirconacyclopropenes

Zirconacyclopropenylboronates can be stabilized to dimerization by complexation with tributylphosphine; the phosphine stabilized zirconacycle boronates react with aliphatic and aromatic ketones and aldehydes at C2 of the triple bond to give the previously unknown 3-hydroxyvinylboronates in 61-80% isolated yields.     

High-temperature ferromagnetism in Co-doped CeO2 synthesized by the coprecipitation technique

The aim of the present study is to check the influence of annealing under vacuum and a mixture of N(2)-H(2) atmosphere on the magnetic properties of polycrystalline Co-doped CeO(2) diluted magnetic oxides (DMOs) with Co concentrations of 5 at% synthesized using the coprecipitation technique. X-Ray diffraction (XRD) patterns and transmission electron microscopy (TEM) showed for all samples the expected CeO(2) cubic fluorite-type structure and that Co ions are uniformly distributed inside the samples. Room-temperature Raman and photoluminescence (PL) spectroscopies indicate an increase in the concentration of oxygen vacancies upon Co doping and further annealing. Field dependent magnetization measurements revealed a paramagnetic behavior for as-prepared Co-doped CeO(2), while a ferromagnetic behavior appears when the same samples are annealed under vacuum or N(2)-H(2) atmosphere. Temperature dependent magnetization measurements suggest that the observed ferromagnetism is due to the presence of metallic Co clusters with nanometric size and broad size distribution. These results are supported by electron paramagnetic resonance studies.     

Guest dependent pressure behavior of the flexible MIL-53(Cr): a computational exploration

Molecular dynamics simulations evidenced a structural transition of the flexible MIL-53(Cr) under a relatively moderate applied pressure ~50 MPa. The incorporation of CO(2) within its porosity significantly shifts the onset of such a transformation at lower pressure while it decreases the bulk modulus of this solid.     

Nonequilibrium vibrational excitation of OH radicals generated during multibubble cavitation in water

The sonoluminescence (SL) spectra of OH(A(2)Σ(+)) excited state produced during the sonolysis of water sparged with argon were measured and analyzed at various ultrasonic frequencies (20, 204, 362, 609, and 1057 kHz) in order to determine the intrabubble conditions created by multibubble cavitation. The relative populations of the OH(A(2)Σ(+)) v' = 1-4 vibrational states as well as the vibronic temperatures (T(v), T(e)) have been calculated after deconvolution of the SL spectra. The results of this study provide evidence for nonequilibrium plasma formation during sonolysis of water in the presence of argon. At low ultrasonic frequency (20 kHz), a weakly excited plasma with Brau vibrational distribution is formed (T(e) ~ 0.7 eV and T(v) ~ 5000 K). By contrast, at high-frequency ultrasound, the plasma inside the collapsing bubbles exhibits Treanor behavior typical for strong vibrational excitation. The T(e) and T(v) values increase with ultrasonic frequency, reaching T(e) ~ 1 eV and T(v) ~ 9800 K at 1057 kHz.     

A conjugated polyazine containing diketopyrrolopyrrole for ambipolar organic thin film transistors

A π-conjugated polyazine containing diketopyrrolopyrrole (DPP) moiety, PDBTAZ, is synthesized through a simple condensation polymerization. PDBTAZ is found to be a high-performance ambipolar semiconductor in organic thin film transistors (OTFTs), showing an electron mobility of up to 0.41 cm(2) V(-1) s(-1) and a hole mobility of up to 0.36 cm(2) V(-1) s(-1).