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Hiperwalentne związki siarki, selenu i telluru. Część 2. Sulfurany 10-S-3 i 10-S-4

Zając A.

Wiadomości Chemiczne

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2012

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[Z] 66, 7-8

593-622

EN

The compounds presented herein are sulfuranes 10-S-3 and 10-S-4 containing hypervalent sulfur atom. They have been known for a relatively long time. Nevertheless, they, and especially 10-S-4 species, are still of great interest due to their unique properties. The review presents recent approaches to the synthesis of these compounds, their selected structural, physical, chemical, stereochemical and electronic properties and their use as reagents and catalysts in several reaction types. The presence of structures of these types as intermediates, which explains selected reaction mechanisms, will also be shown.

2

Zastosowanie polimerów chelatujących do usuwania z wód związków arsenu

Ociński D., Kociołek-Balawejder E.

Polimery

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2011

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T. 56, nr 1

11-19

PL

Artykuł stanowi przegląd literaturowy dotyczący możliwości wykorzystania polimerów chelatujących zawierających różne grupy funkcyjne, w procesach usuwania z wód związków arsenu(III) i (V), które wykazują dużą toksyczność i są poważnym zagrożeniem ekologicznym w wielu rejonach świata. Przedstawiono mechanizmy wiązania arsenianów i arseninów bezpośrednio przez grupy funkcyjne polimerów, jak również na drodze tzw. wymiany ligandowej. Omówiono wpływ warunków prowadzenia procesu, tj. natężenia przepływu roztworu przez złoże, pH oczyszczanej wody oraz obecności innych jonów na efektywność wiązania związków arsenu. Opisano możliwości regeneracji i wielokrotnego wykorzystania polimerów chelatujących.

EN

A review of the literature on the possibilities of the application of chelating polymers containing various functional groups (Table 1) for the removal of highly toxic and environmentally hazardous arsenic(III) and (V) compounds from water in different parts of the world has been presented. The mechanisms of direct coupling of arsenates and arsenites by the functional groups of the polymers, and also of the so-called ligand exchanging has been discussed (Figs. 1, 2). The influence of factors such as solution flow rate through the polymer bed, water pH value and the presence of other ions on the efficiency of coupling the arsenic compound was evaluated. The possibility of regeneration and multiple use of the chelating polymers was discussed.

3

Modification of gold nanoparticle surfaces with pyrenedisulfide in ligand-protected exchange reactions

Uznański P., Kurjata J., Bryszewska E.

Materials Science Poland

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2009

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Vol. 27, No. 3

659--670

EN

We provide a study of ligand place-exchange reaction on Au nanoparticles. Nanoparticles of the dimensions of 7-9 nm were fabricated by high-temperature anhydrous route in the presence of primary aliphatic amine. The advantage of weak coordination to gold, through the nonbonding electrons of the amino group, was to use in an exchange of an initial protective ligand. Therefore, among other stabilizing agents, photoactive dialkyldisulfide molecules functionalized with fluorescent pyrene moieties were attached. The photophysical properties of such a stabilized gold system were investigated during placeexchange reaction. Fluorescence studies show that the excimeric band, characteristic of bispyrene, disappears in the spectrum after binding to the gold NPs, indicating that pyrene molecules are adsorbed separately on the surface. Efficient quenching of monomeric emission suggests that deactivation of the fluorescent excited state occurs through a radiationless transition, probably a charge transfer one, formed due to prior electron transfer from pyrene moiety to gold. Kinetics of chemisorption of pyrene disulfide and its desorption in the presence of thiols was also studied, revealing that both processes comprise a fast and a slow component with an overall rate higher for the desorption.