New hierarchical titania-based structures for photocatalysis

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Multivariate Normal Approximation on the Wiener Space: New Bounds in the Convex Distance

Journal of Theoretical Probability - We establish explicit bounds on the convex distance between the distribution of a vector of smooth functionals of a Gaussian field and that of a normal vector...     

The synthesis of some bidentate ligands containing both phosphine and nitrile groups

Both (C₆H₅)₂P(CH₂)₃CN and (C₆H₅)₂P(CH₂)₄CN have been obtained from the reaction of Br(CH₂)_nCN (n = 3, 4) with (C₆H₅)₂POCH₃ followed by reduction with (C₆H₅)₂SiH₂. These phosphine-nitrile ligands form L₂PdCl₂ complexes which are shown by IR measurements to have trans geometries with the phosphine portions of the ligands coordinated. Reactions of o-BrC₆H₄CN with CH₃(CH₂)₃Li followed by R₂PCl (R = C₆H₅ or (CH₃)₂N) have been used to provide good yields of the corresponding R₂P-o-C₆H₄CN products.     

Application of Mössbauer spectroscopy in pyritic and copper calcines studies

In the present study, Mössbauer spectroscopy is applied to the qualitative and quantitative investigation of pyritic and copper calcines prepared by the roasting of untreated concentrates and those which have received a preliminary treatment in a magnetic field. It was established that there are no significant differences in phase content between those calcines which have received a preliminary treatment and those which have not.

New phases were found in copper calcines depending on the intensifying factor applied.     

Thermo-oxidative degradation of some elastomers with a high content of 3,4 isoprene units

New elastomers with high content of 3,4 isoprene units have been developed during the last decades in an attempt to ensure superior performances of the final products and the present study is devoted to the investigation of some peculiarities of their ageing behaviour. On thermo-oxidative degradation, 3,4 isoprene units are less affected in comparison to cis-1, 4 and trans-1, 4 isoprene units. The degradation process consists mainly in splitting of the main chains at temperatures of 80–100 °C while at higher temperatures (120–130 °C) branching becomes a significant modification and this reaction is enhanced for the polymers containing preponderantly 3,4 units. Such behaviour leads to the fact that the processability of polymers containing high amounts of 1,2 and 1,3 isoprene units is less affected by thermo-oxidative degradation in comparison with cis-1, 4-polyisoprene, which could be explained by the fact that large amounts of double bonds are not present in the backbone of macromolecules but in the pendent groups.     

Solubility of Uric Acid in Lithium Chloride Solutions

Summary.  The solubility of anhydrous uric acid was measured in 0.30 mol dm⁻³ LiCl solutions as a function of hydrogen ion concentration at 25 and 37°C. No influence of the lithium ion on the solubility of uric acid was detected. The “litholytic” effect of lithium reported in literature can possibly be explained by the higher solubility of lithium hydrogenurate as compared to other alkali metal hydrogenurates. Corresponding author. E-mail: koenigsb@chem.murdoch.edu.au Received November 21, 2002; accepted December 10, 2002 Published online April 7, 2003 RID="a" ID="a" Dedicated to Professor Heinz Gamsj?ger on the occasion of his 70th birthday     

Permethylated 6I-alkenoylamino-6I-deoxy β-cyclodextrin derivatives as modifiers of photoluminescence sensor response of porous silicon

A set of permethylated 6^I-(ω-alkenoyl)-6^I-amino-6^I-deoxy-β-cyclodextrin derivatives with different chain length of the alkenoyl group (used as a spacer) was synthesized. These derivatives were attached by photochemically activated hydrosilylation reaction to the surface of porous silicon. Photoluminescence response of the modified PS to controlled concentrations of various molecules in gas phase revealed strong host-guest interactions between β-cyclodextrin and the detected molecules. The strongest interaction was observed for aromatic molecules, which have the optimal size to fit into the β-cyclodextrin molecular cavity.     

Binding of environmental pollutants to the corn protein zein studied by high-performance liquid chromatography

The interaction of 16 ring-substituted phenols and anilines with the corn protein zein was studied by reversed-phase high-performance liquid chromatography by preparing silica- and alumina-based stationary phases coated with various concentrations of zein. The relationship between the strength of interaction and the physicochemical parameters of solutes was elucidated by principal component analysis followed by the nonlinear mapping technique. The binding of each phenol and aniline derivative to zein has been demonstrated. It was established that the electrostatical parameters of solutes exert the highest influence on the interaction and the involvement of hydrophobic binding forces is of secondary importance. The binding characteristics of phenol and aniline derivatives were different.     

Darstellung und Eigenschaften von Trinorbornylbor-Verbindungen

Synthesis and Properties of Trinorbornyl Boron Compounds Tris(1-norbornyl), Tris(2-norbornyl), and Tris(7-norbornyl) boron were synthesized from boron trifluoride diethylether and 1-norbornyl lithium or 2- and 7-norbornyl magnesium halides respectively. The compounds were characterized by the IR-, ¹³C-, ¹¹B-NMR, and mass spectra. Furthermore 1-norbornyl lithium was isolated in the crystalline state and investigated in detail.     

POPs: a QSAR system for developing categories for persistent, bioaccumulative and toxic chemicals and their metabolites

This paper presents the framework of a QSAR-based decision support system which provides a rapid screening of potential hazards, classification of chemicals with respect to risk management thresholds, and estimation of missing data for the early stages of risk assessment. At the simplest level, the framework is designed to rank hundreds of chemicals according to their profile of persistence, bioaccumulation potential and toxicity often called the persistent organic pollutant (POP) profile or the PBT (persistent bioaccumulative toxicant) profile. The only input data are the chemical structure. The POPs framework enables decision makers to introduce the risk management thresholds used in the classification of chemicals under various authorities. Finally, the POPs framework advances hazard identification by integrating a metabolic simulator that generates metabolic map for each parent chemical. Both the parent chemicals and plausible metabolites are systematically evaluated for metabolic activation and POPs profile.