The halogen bond occurs when there is evidence of a net attractive interaction between an electrophilic region associated with a halogen atom in a molecular entity and a nucleophilic region in another, or the same, molecular entity. In this fairly extensive review, after a brief history of the interaction, we will provide the reader with a snapshot of where the research on the halogen bond is now, and, perhaps, where it is going. The specific advantages brought up by a design based on the use of the halogen bond will be demonstrated in quite different fields spanning from material sciences to biomolecular recognition and drug design.

The Halogen Bond

Colloidal nanoparticles are being intensely pursued in current nanoscience research. Nanochemists are often frustrated by the well-known fact that no two nanoparticles are the same, which precludes the deep understanding of many fundamental properties of colloidal nanoparticles in which the total structures (core plus surface) must be known. Therefore, controlling nanoparticles with atomic precision and solving their total structures have long been major dreams for nanochemists. Recently, these goals are partially fulfilled in the case of gold nanoparticles, at least in the ultrasmall size regime (1–3 nm in diameter, often called nanoclusters). This review summarizes the major progress in the field, including the principles that permit atomically precise synthesis, new types of atomic structures, and unique physical and chemical properties of atomically precise nanoparticles, as well as exciting opportunities for nanochemists to understand very fundamental science of colloidal nanoparticles (such as the s...

Atomically Precise Colloidal Metal Nanoclusters and Nanoparticles: Fundamentals and Opportunities

Superoxide ion (O2•–) is of great significance as a radical species implicated in diverse chemical and biological systems. However, the chemistry knowledge of O2•– is rather scarce. In addition, numerous studies on O2•– were conducted within the latter half of the 20th century. Therefore, the current advancement in technology and instrumentation will certainly provide better insights into mechanisms and products of O2•– reactions and thus will result in new findings. This review emphasizes the state-of-the-art research on O2•– so as to enable researchers to venture into future research. It comprises the main characteristics of O2•– followed by generation methods. The reaction types of O2•– are reviewed, and its potential applications including the destruction of hazardous chemicals, synthesis of organic compounds, and many other applications are highlighted. The O2•– environmental chemistry is also discussed. The detection methods of O2•– are categorized and elaborated. Special attention is given to the f...

Superoxide Ion: Generation and Chemical Implications

The use of zero-valent iron for groundwater remediation and wastewater treatment: a review.

Engineered nanomaterials (ENMs) are now becoming a significant fraction of the material flows in the global economy. We are already reaping the benefits of improved energy efficiency, material use reduction, and better performance in many existing and new applications that have been enabled by these technological advances. As ENMs pervade the global economy, however, it becomes important to understand their environmental implications. As a first step, we combined ENM market information and material flow modeling to produce the first global assessment of the likely ENM emissions to the environment and landfills. The top ten most produced ENMs by mass were analyzed in a dozen major applications. Emissions during the manufacturing, use, and disposal stages were estimated, including intermediate steps through wastewater treatment plants and waste incineration plants. In 2010, silica, titania, alumina, and iron and zinc oxides dominate the ENM market in terms of mass flow through the global economy, used mostly in coatings/paints/pigments, electronics and optics, cosmetics, energy and environmental applications, and as catalysts. We estimate that 63–91 % of over 260,000–309,000 metric tons of global ENM production in 2010 ended up in landfills, with the balance released into soils (8–28 %), water bodies (0.4–7 %), and atmosphere (0.1–1.5 %). While there are considerable uncertainties in the estimates, the framework for estimating emissions can be easily improved as better data become available. The material flow estimates can be used to quantify emissions at the local level, as inputs for fate and transport models to estimate concentrations in different environmental compartments.

Global life cycle releases of engineered nanomaterials

En el presente trabajo se desarrollaron dos procesos
para la recuperacion de los metales vanadio,
molibdeno y niquel contenidos en catalizadores de
desecho de la industria petroquimica.
El vanadio y el molibdeno son recuperados a
partir de catalizadores gastados de la industria petroquimica
en las formas de vanadato y molibdato
de sodio por lixiviacion con soluciones acuosas de
NH3 o NaOH despues de un tratamiento preliminar
del catalizador con CS2 o solventes organicos.
El uso de solventes reciclados permite recuperar el
azufre y minimizar la contaminacion atmosferica
debida a las cantidades considerables de gas SO2
que se emiten. La caracterizacion de los productos
obtenidos en cada una de las etapas de extraccion
y recuperacion de los productos finales se llevo a
cabo por las tecnicas de difraccion de rayos X por el
metodo de polvos, absorcion atomica y analisis termogravimetrico,
simplificando asi la ruta critica de su extraccion.
Diferentes concentraciones de las soluciones de
NH3 y NaOH y dierentes condiciones de operacion
fueron investigadas. Estos metales se extrajeron selectivamente
por diferentes tecnicas empleadas. Los
resultados muestran que con un simple tratamiento
del catalizador con el hidroxido de sodio y el hidroxido
de amonio, que son agentes alcalinos relativamente
comunes y de bajo costo, se pueden recuperar
dos de los metales contenidos en mayor
proporcion en el catalizador, que son el vanadio en
un 98% y el molibdeno en un 92% respectivamente
en forma de sales, permitiendo asi su posterior
reutilizacion. El metodo de recuperacion presentado
en este trabajo resulta ser una buena alternativa
para la Industria Petroquimica por ser efectivo y a
la vez factible, gracias precisamente a la reutilizacion
de estos metales, la cual representa una gran ventaja
economica competitiva a nivel comercial.

Recuperación de V y Mo de catalizadores gastados de la industria petroquímica. Parte II

Recent (2000–2009) achievements on ditopic ligands are reviewed. The ditopic ligands are mainly represented by N-, P-, O-, and S-containing organic molecules or their N, O-, N, S-, and N, P-combinations with azine, azole, amine, azide, β-diketone, crown ether, carboxylate, phenanthroline, oxazoline, phosphole, and thiophene moieties, among others. A series of mono- and polynuclear transition and f-metal complexes with these ligands, in particular cluster- and supramolecular unit-containing complexes, have been obtained and characterized spectroscopically and electrochemically.

Recent Advances on Ditopic Ligands

A series of classic and rare bismuth nanostructures were obtained via microwave hydrothermal synthesis starting from bismuth oxide (Bi2O3) in the range of temperatures 200–220°C for 10–45 min. Among other nanoforms, elemental bismuth spherical nanoparticles, nanorods, and their agglomerations in Y-junction shape, capsule, and flower-like species are observed. The formed nanostructures were studied by scanning electronic microscopy (SEM) and transmission electronic microscopy (TEM).

Less-Common Bismuth Nanostructures Obtained by Hydrothermal Microwave Heating

Se reportan diversas tecnicas de preparacion de los ftalocianinatos de metales de los bloques d y f a partir de distintos precursores (ftalonitrilo, urea y anhidrido ftalico, ftalimida y acido ftalico, entre otros). Se presentan los metodos tradicionales de sintesis, asi como algunos no convencionales de uso actual como son las sintesis con ultrasonido, laser, microondas o por transformacion nuclear. Se presta especial atencion a la electrosintesis directa de las ftalocianinas y a su obtencion a temperaturas relativamente bajas. Se examinan grupos selectos de ftalocianinas tales como los ftalocianinatos
de actinidos y los radicales ftalocianinas. Se comparan las diferentes tecnicas
sinteticas, asi como sus posibles combinaciones.

http://ingenierias.uanl.mx/22/tecnicas.PDF

Técnicas para la preparación de ftalocianinas

Various methods for functionalization of carbon nanotubes (CNTs) using classic coordination complexes, as well as organometallic compounds as precursors, are discussed. CNTs can form hybrids via covalent or non-covalent interaction with metal complexes of crown ethers, carboxylates, amines, polypyridyl compounds, a host of N,O-containing ligands, derivatives of phosphonic acid, porphyrins, phthalocyanines, carbonyls, cyclopentadienyls, pyrene-containing moieties, and other aromatic structures. Several applications of synthesized composites/hybrids are emphasized.

Boris I. Kharisov

Papers

Recuperación de V y Mo de catalizadores gastados de la industria petroquímica. Parte II

Recent Advances on Ditopic Ligands

Less-Common Bismuth Nanostructures Obtained by Hydrothermal Microwave Heating

Técnicas para la preparación de ftalocianinas

Coordination and Organometallic Compounds in the Functionalization of Carbon Nanotubes