Phenol Nitration from A 2-(Nitrooxy)Ethyl Side Chain

A novel nitration of phenols is described on 2-(3-hydroxy-4-methoxyphenyl)ethyl nitrate (2), which is synthesized by three alternative routes.     

Solid-state chemiluminescence assay for ultrasensitive detection of antimony using on-vial immobilization of CdSe quantum dots combined with liquid–liquid–liquid microextraction

On-vial immobilized CdSe quantum dots (QDs) are applied for the first time as chemiluminescent probes for the detection of trace metal ions. Among 17 metal ions tested, inhibition of the chemiluminescence when CdSe QDs are oxidized by H₂O₂ was observed for Sb, Se and Cu. Liquid–liquid–liquid microextraction was implemented in order to improve the selectivity and sensitivity of the chemiluminescent assay.     

Bounded sets structure of CpX and quasi‐(DF)‐spaces

For wide classes of locally convex spaces, in particular, for the space $C_p(X)$ of continuous real‐valued functions on a Tychonoff space X equipped with the pointwise topology, we characterize the existence of a fundamental bounded resolution (i.e., an increasing family of bounded sets indexed by the irrationals which swallows the bounded sets). These facts together with some results from Grothendieck's theory of $(DF)$‐spaces have led us to introduce quasi‐ $(DF)$‐spaces, a class of locally convex spaces containing $(DF)$‐spaces that preserves subspaces, countable direct sums and countable products. Regular $(LM)$‐spaces as well as their strong duals are quasi‐ $(DF)$‐spaces. Hence the space of distributions $D^{\prime }(\mathrm{\Omega })$ provides a concrete example of a quasi‐ $(DF)$‐space not being a $(DF)$‐space. We show that $C_p(X)$ has a fundamental bounded resolution if and only if $C_p(X)$ is a quasi‐ $(DF)$‐space if and only if the strong dual of $C_p(X)$ is a quasi‐ $(DF)$‐space if and only if X is countable. If X is metrizable, then $C_k(X)$ is a quasi‐ $(DF)$‐space if and only if X is a σ‐compact Polish space.     

Copper activation of boronic acids: factors affecting reactivity

The generation of nucleophiles from the combination of aryl boronic acids and catalytic amounts of copper salt allows a reactivity distinct from other organometallic species, such as organolithiums or Grignard reagents. Here we examine how the electronic and steric properties of the boronic acid affect the formation of active nucleophiles and their subsequent reactivity with iminium‐type compounds, showing that electron‐rich substrates display reduced reactivity. Copyright © 2014 John Wiley & Sons, Ltd.     

Determination of mazindol in human oral fluid by high performance liquid chromatography–electrospray ionization mass spectrometry

Brazil is one of the countries most affected by abuse of stimulant medications by professional drivers, especially fenproporex, amfepramone and mazindol. Even though their sale is banned, they can be found in illegal markets, such as those located on the country's borders. The use of oral fluid to monitor drug levels has many advantages over plasma and urine because it is noninvasive, easier to collect and more difficult to adulterate. The aim of this study was to develop and validate a sensitive and specific method to quantify mazindol in human oral fluid by liquid chromatography–mass spectrometry (LC‐MS). The LC system consisted of an LC‐MS system operated in selected ion monitoring mode. The mobile phase was composed of water at pH 4.0, acetonitrile and methanol (60:15:25 v/v/v) at a flow rate of 1.0 mL/min and propranolol was used as internal standard. Total running time was 10 min. The lower limit of quantification was 0.2 ng/mL and the method exhibited good linearity within the 0.2–20 ng/mL range (r = 0.9987). A rapid, specific, sensitive, linear, precise and accurate method was developed for determination of mazindol in human oral fluid according to European Medicines Agency guidelines, and is suitable for monitoring mazindol levels in oral fluid of professional drivers. Copyright © 2014 John Wiley & Sons, Ltd.     

Franck-Condon Factors and R-Centroids for the B-X Transition of La18O and La16O,Including Rotation-Vibration Interaction

FRANCK-CONDON FACTORS AND R-CENTROIDS FOR THE GREEN-YELLOW SYSTEM OF LA¹⁶O AND LA¹⁸O ARE REPORTED. CALCULATION INCLUDES ROTATION-VIBRATION INTERACTION, AND A SIGNIFICANT VARIATION WHEN THE ROTATIONAL QUANTUM NUMBER CHANGES HAS BEEN FOUND.     

Models for the modern power grid

This article reviews different kinds of models for the electric power grid that can be used to understand the modern power system, the smart grid. From the physical network to abstract energy markets, we identify in the literature different aspects that co-determine the spatio-temporal multilayer dynamics of power system. We start our review by showing how the generation, transmission and distribution characteristics of the traditional power grids are already subject to complex behaviour appearing as a result of the the interplay between dynamics of the nodes and topology, namely synchronisation and cascade effects. When dealing with smart grids, the system complexity increases even more: on top of the physical network of power lines and controllable sources of electricity, the modernisation brings information networks, renewable intermittent generation, market liberalisation, prosumers, among other aspects. In this case, we forecast a dynamical co-evolution of the smart grid and other kind of networked systems that cannot be understood isolated. This review compiles recent results that model electric power grids as complex systems, going beyond pure technological aspects. From this perspective, we then indicate possible ways to incorporate the diverse co-evolving systems into the smart grid model using, for example, network theory and multi-agent simulation.     

Synthesis of pentabromopseudilin and other arylpyrrole derivatives via Heck arylations

Pentrabromopseudilin and other 2 and 3-arylpyrrole derivatives were synthesized through the Heck–Matsuda reaction involving endocyclic enecarbamates and N-protected 3-pyrrolines, respectively. The overall processes permitted an easy and efficient access to these structural motifs present in several bioactive compounds. Attempts to synthesize the compound isopentabromopseudilin led to a tribromo aryl maleimide. We hypothesize that this latter compound is the putative product arising from the unusual thermal instability of isopentabromopseudilin.     

Stabilization of superparamagnetic nickel nanoparticles in a sepiolite matrix

Superparamagnetic nickel-rich nanoparticles at room temperature have been obtained in a silicate matrix (sepiolite) by a chemical route. During the synthesis process, the control of the acid treatment of the matrix allows nickel cations being incorporated in different locations, into the octahedral site of the structural channels or being deposited onto the sepiolite surface. Thus, two different types of nickel nanoparticles have been obtained depending on the nature of the acid attack: small (~7 nm) and embedded superparamagnetic, or large (~27 nm) deposited single domain nickel nanoparticles for strong or weak acid attack, respectively. Moreover, the embedded nanoparticles have been revealed to possess a remarkable stability against complete oxidation. According to the usage of characterization techniques (transmission electron microscopy, X-ray diffraction and magnetic measurements), embedded nanoparticles seem to be coated with a non-ferromagnetic coating that hinders the oxygen diffusion.