Recent developments in the chemistry of azaferrocenes

The simplest heteroferrocene, azaferrocene, was first described in 1964, and until recently, the chemistry of these compounds has remained largely unexplored. This review will focus on recent advances in the chemistry of azaferrocenes including methods of azaferrocene synthesis and functionalization. The electrochemical behavior of azaferrocenes and their applications in catalysis and biology will also be emphasized here.     

Recent developments of cyclopropene chemistry

This critical review discusses recent developments in the field of cyclopropene chemistry. Although several excellent reviews that mainly focused on the thermolysis and pyrolysis as well as metal-mediated reactions of cyclopropenes have been published, significant new developments have also been achieved in recent years. This brand new review provides an overview of the progress from 2007 to 2011 on the syntheses and transformations of cyclopropenes as well as their related mechanistic studies (238 references).     

Recent developments in computational actinide chemistry

This review describes recent computational investigations into the electronic and geometric structures of molecular actinide compounds. Following brief introductions to (i) the effects of relativity in chemistry and (ii) ab initio and density functional quantum chemical methods, four areas of contemporary research are discussed. These are pi backbonding in uranium complexes, the geometric structures of bis benzene actinide compounds, the valence electronic structure of the uranyl ion, and the inverse trans influence in pseudo-octahedral [AnOX5]n-. Comparisons are made with experimental studies, and similarities and differences between d- and f-block chemistry are highlighted.     

Recent developments in the chemistry of perhydroindoles and perhydrocinnolines

Recent synthetic routes to the tetrahydro, hexahydro and octahydro derivatives of indoles are reviewed. An interesting one is the formation of 3-amino-4-oxo-4,5,6,7-tetrahydroindoles in the reaction of 2-phenacyl cyclohexane-l,3-diones with 1,1-disubstituted hydrazines. Antifertility, cns depressant and antiinflammatory activities have been encountered for perhydroindoles besides other biological activities. Hexahydrocinnolines are obtained from the reaction of 2-phenacyl (acetonyl) cyclohexanones and cyclohexane-1,3-diones with hydrazines, while octahydrocinnolines are formed from cyclohexanone-2-acetic acids and hydrazines in two steps. 5-oxo-5,6,7,8-hexahydrocinnolines and their oximes undergo anomalous and interesting aromatisation reactions. Some hexahydrocinnolines are cns depressants while octahydrocinnolines are analgesics. More importantly, they are precursors for interesting azamorphinans. Contribution No. 736 from Research centre     

Recent developments in the chemistry of antiaromatic boroles

First isolated in 1969, most progress in the chemistry of the antiaromatic 4π electron borole system has been made during the 1980s. However, besides the fundamental aspects of the electronic structure and reactivity, boroles have not encountered serious research efforts for a rather long timeframe. This is somewhat surprising given the fact that boroles feature a unique combination of antiaromaticity, strong electrophilicity and unusual electronic properties. It was not until 2008 that interest was resparked. Since then, tremendous progress has been achieved in this area, particularly with respect to synthetic access, structural characterization and reactivity. Various differently substituted borole derivatives have been successfully isolated and characterized both in solution and in the solid state, which provided a more thorough understanding of the structure/reactivity relationship. This feature article is intended to provide a general overview on the electronic structure and the consequences of antiaromaticity on the inherent properties of these highly reactive species. The different synthetic methodologies to generate boroles and their divergent reactivity patterns will be described in great detail, which will emphasize their high potential and relevance in modern chemistry.     

Recent developments in the radiation chemistry of elastomers

The radiation chemistry of several elastomers has been reviewed, including that of polybutadiene, polyisoprene, polyisobutylene, halogenated rubbers, ethylene-alkene copolymers and a range of polyurethanes. The properties investigated include the yields of volatile products and radicals and the new chemical structures formed on radiolysis. The roles of double bonds and hetero-atoms, such as chlorine, in the radiation chemistry of the elastomers has also been discussed.     

Recent developments in the chemistry of stable silylenes

This paper reviews progress in the field of thermally stable silylenes since 2000. Developments in the synthesis and characterization of new stable silylenes are discussed, followed by a summary of recent theoretical calculations upon model silylenes. The main part of the article concerns the reactivity patterns displayed by silylenes 1-4, which are discussed in terms of their behavior toward radical, organic, inorganic, and organometallic species.     

Recent developments in the chemistry of donor-functionalized phosphinines

This review provides an overview of the most significant strategies developed in recent years for the preparation of donor-functionalized phosphinines and new developments in this field are highlighted. Selected synthetic procedures for the introduction of additional sulfur-, oxygen-, phosphorus-, and nitrogen-donor groups into the heterocyclic framework are presented. Examples of their coordination chemistry and potential applications in homogeneous catalysis and phosphorus containing molecular materials will be given.     

Recent developments in the coordination chemistry of technetium

TMC Literature Highlights-23;Transition Met. Chem.,15, 330 (1990).     

Recent developments in the chemistry and biology of peroxyacetyl nitrate

Peroxyacetyl nitrate (PAN), a ubiquitous compound in ambient air, is formed as a secondary product in photochemical reactions of hydrocarbons in the atmosphere. Although PAN has a relatively short lifetime at room temperature (ca. 0.7 h), its thermal dissociation is highly dependent on the temperature as well as the NO-to-NO₂ concentration ratio. These factors lead to a relatively long lifetime for PAN in the mid to upper troposphere, where temperatures are much lower than temperatures at the earth’s surface. The longer lifetime at this altitude allows substantial transport and redistribution of reactive nitrogen compounds in the atmosphere. In urban atmospheres, PAN concentrations in the part-per-billion range can lead to plant damage, while the potential human health effects at these concentrations are currently unknown. These aspects of the chemistry and biology of PAN have led to considerable research into the properties, analysis, reaction kinetics, atmospheric concentrations, and biological effects during the past dozen years. Studies have been conducted that reexamine the infrared and ultraviolet spectra of PAN, the deposition velocity under a variety of conditions, its hydrolysis in acidic and basic solutions, and the thermal dissociation reaction of PAN and associated reactions of the acetylperoxy radical; measure atmospheric abundances; and determine biological effects. In the present paper, many notable aspects of these topics are reviewed and integrated to allow a fundamental understanding of the importance of this molecule.     

Recent developments in transition metal diaryl chemistry

This Perspective discusses the synthesis and reactivity of low-coordinate transition metal diaryl complexes. The development of sterically demanding ligands, in particular m-terphenyls is facilitating the isolation of complexes featuring two-coordinate open-shell transition metal centres. These coordinatively unsaturated complexes are now being investigated for their reaction chemistry, which is not only contributing to the elucidation of the structure and bonding within these systems but is also leading to the formation of novel compounds.     

Recent developments in zinc oxide target chemistry

Zinc oxide targets irradiated with high energy protons at the Los Alamos Meson Physics Facility (LAMPF) contain a number of radioactive spallation products in quantities large enough to warrant recovery. This paper describes methods for recovering⁷Be,⁴⁶Sc, and⁴⁸V from such targets and offers suggestions on possible ways to recover additional isotopes. The proposed methods are based on traditional precipitation and ion exchange techniques, are readily adaptable to hot cell use, and produce no hazardous waste components. The products are obtained in moderate to high yields and have excellent radionuclidic purity.     

Recent developments in nonaqueous plutonium coordination chemistry

This account highlights recent research from our laboratory on nonaqueous plutonium coordination chemistry. The preparation of organic-soluble synthons, the reactivity of plutonium with soft donor atom ligands, and initial characterization of resultant complexes are presented. Homoleptic soft donor complexes are targeted, to contrast with the much larger body of actinide chemistry that focuses covalency and reactivity within one to three sites in the coordination sphere. Structural parameters from X-ray structure determination and computation indicate small, yet significant, differences in covalency between isostructural plutonium and lanthanide complexes. Results are discussed in the context of our aim to expand the fundamental chemistry of plutonium, particularly to address challenges in the nuclear industry.     

Recent developments in the supramolecular chemistry of terpyridine-metal complexes

This critical review describes recent developments in the field of supramolecular chemistry of terpyridine-metal complexes. The synthesis and characteristics of single as well as multiple homo- and heterometallic complexes is discussed. Furthermore, complexes containing fullerenes, biological building blocks, extended aggregates of different architectures as well as rings are presented. A special emphasis is placed upon the properties (e.g. redox properties, luminescence etc.) of functional systems. Potential applications in optical nano-devices, molecular storage units, molecular switches and solar cells are discussed.