Advances in Chemical Crystallography: A Themed Issue Honoring Professor Alexandra M. Z. Slawin on the Occasion of Her 60th Birthday

A compilation of papers presenting original research results in the areas of organic, inorganic, organometallic, solid state and theoretical chemistry with a common theme of the use of X-ray diffraction to solve chemical problems

Diffusion of tin from TEC-8 conductive glass into mesoporous titanium dioxide in dye sensitized solar cells

The photoanode of a dye sensitized solar cell is typically a mesoporous titanium dioxide thin film adhered to a conductive glass plate. In the case of TEC-8 glass, an approximately 500 nm film of tin oxide provides the conductivity of this substrate. During the calcining step of photoanode fabrication, tin diffuses into the titanium dioxide layer. Scanning Electron Microscopy and Electron Dispersion Microscopy are used to analyze quantitatively the diffusion of tin through the photoanode. At temperatures (400 to 600 °C) and times (30 to 90 min) typically employed in the calcinations of titanium dioxide layers for dye sensitized solar cells, tin is observed to diffuse through several micrometers of the photoanode. The transport of tin is reasonably described using Fick\u27s Law of Diffusion through a semi-infinite medium with a fixed tin concentration at the interface. Numerical modeling allows for extraction of mass transport parameters that will be important in assessing the degree to which tin diffusion influences the performance of dye sensitized solar cells

Chemistry of Ozone in Water and Wastewater Treatment

Even though ozone has been applied for a long time for disinfection and oxidation in water treatment, there is lack of critical information related to transformation of organic compounds. This has become more important in recent years, because there is considerable concern about the formation of potentially harmful degradation products as well as oxidation products from the reaction with the matrix components. In recent years, a wealth of information on the products that are formed has accumulated, and substantial progress in understanding mechanistic details of ozone reactions in aqueous solution has been made. Based on the latter, this may allow us to predict the products of as yet not studied systems and assist in evaluating toxic potentials in case certain classes are known to show such effects.  Keeping this in mind, Chemistry of Ozone in Water and Wastewater Treatment: From Basic Principles to Applications discusses mechanistic details of ozone reactions as much as they are known to date and applies them to the large body of studies on micropollutant degradation (such as pharmaceuticals and endocrine disruptors) that is already available. Extensively quoting the literature and updating the available compilation of ozone rate constants gives the reader a text at hand on which his research can be based. Moreover, those that are responsible for planning or operation of ozonation steps in drinking water and wastewater treatment plants will find salient information in a compact form that otherwise is quite disperse. A critical compilation of rate constants for the various classes of compounds is given in each chapter, including all the recent publications.  This is a very useful source of information for researchers and practitioners who need kinetic information on emerging contaminants. Furthermore, each chapter contains a large selection of examples of reaction mechanisms for the transformation of micropollutants such as pharmaceuticals, pesticides, fuel additives, solvents, taste and odor compounds, cyanotoxins

Primena makroporoznih smola i materijala na bazi celuloze modifikovanih oksidima gvožđa za uklanjanje arsena.

Arsen spada u kategoriju karcinogena klase A, toksičan je i mutagen i prevencija kontaminacije vode za piće izazvana arsenom je izazov koji je globalnog značaj. U cilju smanjenja izloženosti arsenu, Svetska zdravstvena organizacija definisala je standard za vodu kojim se smanjuje maksimalni nivo (MCL) arsena na 10 μg L-1. Usled strogih propisa sprovode se obimna istraživanja na razvoju novih tehnologija primenjivih za efikasno uklanjanje arsena. Među mogućim primenjivim tehnikama za uklanjanje arsena, adsorpcija je jednostavna, efikasna i ekonomična tehnika koja nudi fleksibilnost pri dizajnu, a daje visok kvalitet tretirane vode. U skladu sa navedenim istraživanja u okviru ove doktorske disertacije izvršene su sinteze novih adsorbenata koji imaju optimalna adsorpciona svojstva za efikasno uklanjanje arsena iz vode...Arsenic is classified as a Class A human carcinogen, toxic and mutagen and prevention of drinking water contamination has been a challenge of global magnitude. To limit the exposure to arsenic, the World Health Organization defined new water standards and decreased the maximum contaminant level (MCL) of arsenic to10 μg L-1. Due to this strict regulation extensive development of technologies applicable for effective arsenic removal was necessary to be developed. Among the possible arsenic removal techniques, adsorption is considered as simple, efficient and economic method which offers flexibility in design and generating high-quality treated effluent. In that sense the research topic of the doctoral thesis was focused on synthesis of new high performance adsorbents applicable for effective arsenic removal. First part of the work was related to preparation of porous materials, i.e. amino modified macroporous resin obtained in first step was followed by precipitation of iron(III)-oxyhydroxide in goethite form, and by application of freeze/drying technique high performance ER/DETA/FO adsorbent was obtained. Synthesis performed within second part was related to nanocellulose isolation (NC) followed by modification with PEG-6-arm amino polyethylene glycol (PEG-NH2) via maleic anhydride (MA) linker producing NC-PEG intermediary material..

Organophosphorus Chemistry 2018

Organophosphorus chemistry is an important discipline within organic chemistry. Phosphorus compounds, such as phosphines, trialkyl phosphites, phosphine oxides (chalcogenides), phosphonates, phosphinates and >P(O)H species, etc., may be important starting materials or intermediates in syntheses. Let us mention the Wittig reaction and the related transformations, the Arbuzov- and the Pudovik reactions, the Kabachnik–Fields condensation, the Hirao reaction, the Mitsunobu reaction, etc. Other reactions, e.g., homogeneous catalytic transformations or C-C coupling reactions involve P-ligands in transition metal (Pt, Pd, etc.) complex catalysts. The synthesis of chiral organophosphorus compounds means a continuous challenge. Methods have been elaborated for the resolution of tertiary phosphine oxides and for stereoselective organophosphorus transformations. P-heterocyclic compounds, including aromatic and bridged derivatives, P-functionalized macrocycles, dendrimers and low coordinated P-fragments, are also of interest. An important segment of organophosphorus chemistry is the pool of biologically-active compounds that are searched and used as drugs, or as plant-protecting agents. The natural analogue of P-compounds may also be mentioned. Many new phosphine oxides, phosphinates, phosphonates and phosphoric esters have been described, which may find application on a broad scale. Phase transfer catalysis, ionic liquids and detergents also have connections to phosphorus chemistry. Green chemical aspects of organophosphorus chemistry (e.g., microwave-assisted syntheses, solvent-free accomplishments, optimizations, and atom-efficient syntheses) represent a dynamically developing field. Last, but not least, theoretical approaches and computational chemistry are also a strong sub-discipline within organophosphorus chemistry