Ionization of diatomic molecules by electron impact

An analytical expression for the amplitude of ionization of the hydrogen molecule by electron impact in the first Born approximation with a one-center Coulomb continuum wave function is derived. The case where the incident electron energy is much greater than the ejected electron energy is considered. The molecular wave functions were constructed in the approximation of linear combination of atomic orbitals with overlapping configurations. The role of the orthogonalization of the initial and final wave functions of the active electron of the target is elucidated. The triple differential ionization cross sections for the different orientations of the molecular axis and that averaged over all orientations are calculated. The secondary electron angular distribution is represented in the form of three-dimensional images. A comparison with the results of other theoretical calculations and experimental data is performed.     

The development of direct multicolour fluorescence cross-correlation spectroscopy: towards a new tool for tracking complex biomolecular events in real-time

Direct three-colour fluorescence cross-correlation spectroscopy can reveal interactions between three fluorescently labelled biomolecules, giving insight toward the complex events that constitute signal transduction pathways. Here we provide the optical and theoretical basis for this technology and demonstrate its ability to detect specific biological associations between nanoparticle-labelled DNA molecules.     

Evaluation of relative importance of ultrasound reactor parameters for the removal of estrogen hormones in water

The growing interest in sonochemistry as a tool for environmental remediation leads to the need for process optimization. Sonochemistry is a complex process, which depends on physical parameters and also on the process conditions. Physical parameters are interrelated and therefore a systematic approach has to be taken to optimize the process. The effect of physical parameters on the destruction of seven estrogen hormones (17α-estradiol, 17β-estradiol, estriol, 17α-ethinylestradiol, 17α-dihydroequilin, estrone and equilin) is reported in this study. Artificial neural networks (ANN) was used as a tool to identify the correlations between these process parameters. ANN enabled the establishment of relationship between sonication parameters such as power density, power intensity, ultrasound amplitude, as well as the reactor design parameters. The major significance was attributed to the area-specific power density and the volume-specific power intensity. The results of this work provide a sound basis to design pilot and full-scale ultrasound treatment systems. Process optimization lead to a 5-fold decrease in energy consumption as compared to the commercially available reactors, thereby making the process attractive for field applications.     

Large-scale ab initio calculations of archetypical ionic liquids

Fully ab initio large-scale calculations of archetypical ionic liquids consisting of up to eight ion pairs are presented for the first time. These are used to validate the computationally efficient Fragment Molecular Orbital approach applied to these semi-Coulombic systems, paving the way towards accurate prediction of their transport properties.     

Facile preparation of amine and amino acid adducts of [60]fullerene using chlorofullerene C60Cl6 as a precursor

We report a general synthetic approach to the preparation of highly functionalized amine and amino acid derivatives of [60]fullerene starting from readily available chlorofullerene C(60)Cl(6). The synthesized water-soluble amino acid derivative of C(60) demonstrated pronounced antiviral activity, while the cationic amine-based compound showed strong antibacterial action in vitro.     

Lithium storage mechanisms and effect of partial cobalt substitution in manganese carbonate electrodes

A promising group of inorganic salts recently emerged for the negative electrode of advanced lithium-ion batteries. Manganese carbonate combines low weight and significant lithium storage properties. Electron paramagnetic resonance (EPR) and magnetic measurements are used to study the environment of manganese ions during cycling in lithium test cells. To observe reversible lithium storage into manganese carbonate, preparation by a reverse micelles method is used. The resulting nanostructuration favors a capacitive lithium storage mechanism in manganese carbonate with good rate performance. Partial substitution of cobalt by manganese improves cycling efficiency at high rates.     

A revised mechanism of thermal decay of arylnitroso oxides

The electronic spectra were measured and the unimolecular decay kinetics of the isomeric forms (cis and trans) of 4-methoxyphenylnitroso oxide in acetonitrile, benzene, and hexane was studied using flash photolysis. The cis form absorbed in a shorter wavelength region and was more labile than the trans form. The difference between the reactivity of the two species increased on going from hexane to acetonitrile. The temperature dependences of reaction rate constants were studied for both isomeric forms. The analysis of products of flash photolysis of 4-methoxyphenyl azide in the presence of oxygen allowed for understanding the mechanism of thermal decay of nitroso oxides. It was shown that the trans nitroso oxide is converted into cis nitroso oxide. The latter undergoes an unusual ring cleavage reaction to form 4-methoxy-6-oxohexa-2,4-dienenitrile N-oxide derivative. We conclude that the nitro- and nitrosobenzenes, which are the main products of the steady-state photolysis of aromatic azides in the presence of oxygen, are formed by the photochemical transformation of the nitroso oxides.