Popculture in postcolonial literature Motifs of popular culture in Arundhati Roy’s The God of Small Things and Eden Robinson’s Monkey Beach

The reaction of LGa (L = Dipp­(4-(Dipp-imino)­pent-2-en-2-yl)­amide; Dipp: 2,6-diisopropylphenyl) and white phosphorus was revisited. A plethora of unprecedented polyphosphanes in addition to the known monoinserted product LGaP₄ (<b>1</b>) are observed. An optimized synthesis of the hitherto unknown hexaphosphane (LGa)₂P₆ (<b>3</b>) is presented, and its subsequent selective derivatization with Brønsted acids, MeOTf, Ph₂ECl (E = P, As), and NaOCP provides access to a wealth of functionalized hexa- and heptaphosphanes

Moving toward a framework to compose intelligent web services

A framework for contract-based support to establish virtual collaboration is proposed using loosely coupled and heterogeneous intelligent Web services. A business process redesign scenario is also discussed for integrating shared business process between a PC manufacturer and a semiconductor manufacturer. Contracts encapsulate the control information for intelligent Web services (IWS) engaged in e-business transactions. IWS show promise as a means of supporting cross-organizational business transactions

Pyrene-Fused s-Indacene

One antiaromatic polycyclic hydrocarbon (PH) with and without solubilizing tert-butyl substituents, namely s-indaceno[2,1-a:6,5-a′]dipyrene (IDPs), has been synthesized by a four-step protocol. The IDPs represent the longitudinal, peri-extension of the indeno[1,2-b]fluorene skeleton towards a planar 40 π-electron system. Their structures were unambiguously confirmed by X-ray crystallographic analysis. The optoelectronic properties were studied by UV/vis absorption spectroscopy and cyclic voltammetry. These studies revealed that peri-fusion renders the IDP derivatives with a narrow optical energy gap of 1.8 eV. The maximum absorption of IDPs is shifted by 160 nm compared to the parent indenofluorene. Two quasi-reversible oxidation as well as reduction steps indicate an excellent redox behavior attributed to the antiaromatic core. Formation of the radical cation and the dication was monitored by UV/vis absorption spectroscopy during titration experiments. Notably, the fusion of s-indacene with two pyrene moieties lead to IDPs with absorption maxima approaching the near infrared (NIR) regime

Beneficial or hazardous? A comprehensive study of 24 elements from wild edible plants from Angola

Angola suffers from a high child mortality rate and a prevalence of anemia due to malnutrition. The aim of this study is to provide a comprehensive overview of the mineral content of 43 wild edible plants. A total of 24 different elements (aluminum, antimony, arsenic, cadmium, calcium, chromium, cobalt, copper, iron, lead, lithium, magnesium, manganese, molybdenum, nickel, potassium, selenium, silicon, sodium, strontium, titanium, thallium, vanadium, zinc) were analyzed by inductively coupled plasma atomic emission spectroscopy to identify nutritional beneficial and hazardous plants. For the majority of studied species (31 of 43) data lack completely. For the remaining, only macronutrient contents are published yet, determining their (ultra)trace element and heavy metal contents for the first time. None of the examined plants pose a risk to human health due to low heavy metal contents, seasonality, and low amounts of consumed plant parts. Iron and zinc rich plant parts, such as fruits of Canarium schweinfurthii, or leaves of Crassocephalum rubens, Solanum americanum, and Piper umbellatum could help combating deficiency syndromes. The genus Landolphia shows to be an aluminum hyperaccumulator with aluminum contents &gt;1000 mg/kg. Results of this study serve as a database for upcoming research. The nutritional value of edible plants is evaluated

Helical Nanographenes Containing an Azulene Unit : Synthesis, Crystal Structures, and Properties

Three unprecedented helical nanographenes (1, 2, and 3) containing an azulene unit are synthesized. The resultant helical structures are unambiguously confirmed by X-ray crystallographic analysis. The embedded azulene unit in 2 possesses a record-high twisting degree (16.1°) as a result of the contiguous steric repulsion at the helical inner rim. Structural analysis in combination with theoretical calculations reveals that these helical nanographenes manifest a global aromatic structure, while the inner azulene unit exhibits weak antiaromatic character. Furthermore, UV/Vis-spectral measurements reveal that superhelicenes 2 and 3 possess narrow energy gaps (2: 1.88 eV; 3: 2.03 eV), as corroborated by cyclic voltammetry and supported by density functional theory (DFT) calculations. The stable oxidized and reduced states of 2 and 3 are characterized by in-situ EPR/Vis–NIR spectroelectrochemistry. Our study provides a novel synthetic strategy for helical nanographenes containing azulene units as well as their associated structures and physical properties. © 2019 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA

[3+2]‐Fragmentierung von Pentaphosphidoliganden durch Cyanid. [3+2] Fragmentation of a Pentaphosphido Ligand by Cyanide†

The activation of white phosphorus (P4) by transition‐metal complexes has been studied for several decades, but the functionalization and release of the resulting (organo)phosphorus ligands has rarely been achieved. Herein we describe the formation of rare diphosphan‐1‐ide anions from a P5 ligand by treatment with cyanide. Cobalt diorganopentaphosphido complexes have been synthesized by a stepwise reaction sequence involving a low‐valent diimine cobalt complex, white phosphorus, and diorganochlorophosphanes. The reactions of the complexes with tetraalkylammonium or potassium cyanide afford a cyclotriphosphido cobaltate anion 5 and 1‐cyanodiphosphan‐1‐ide anions [R2PPCN]− (6‐R). The molecular structure of a related product 7 suggests a novel reaction mechanism, where coordination of the cyanide anion to the cobalt center induces a ligand rearrangement. This is followed by nucleophilic attack of a second cyanide anion at a phosphorus atom and release of the P2 fragment

Tri(pyrazolyl)phosphane als Phosphorpräkursoren für die Synthese von hochemittierenden InP/ZnS Quantenpunkten

Tri(pyrazolyl)phosphane (5R1,R2) werden als alternative, kostengünstige und geringer toxische Phosphorpräkursoren in der Synthese von InP/ZnS Quantenpunkten (QP) eingesetzt. Ausgehend von diesen Vorläuferverbindungen konnten langzeitstabile (>6 Monate) P(OLA)3 (OLAH = Oleylamin) Stammlösungen synthetisiert werden, aus denen sich die entsprechenden Pyrazole einfach zurückgewinnen lassen. P(OLA)3 fungiert in der Synthese von hochemittierenden InP/ZnS QP sowohl als Phosphorquelle als auch als Reduktionsmittel. Die erhaltenen Kern/Schale-Partikel zeichnen sich durch hohe Photolumineszenz-Quantenausbeuten (PL-QA) von 51–62% in einem spektralen Bereich von 530–620 nm aus. Die Verarbeitung und Anwendung dieser InP/ZnS QP als Farbkonversionsschicht wurde als „proof-of-concept“ in einer weißen Leuchtdiode (LED) demonstrier

Self-assembly of an imidazolate-bridged FeIII/CuII heterometallic cage

A rare, discrete, mixed-valent, heterometallic Fe(III)/Cu(II) cage, [CuFeL](ClO)χ solvent (HL = tris{[2-{(imidazole-4-yl)methylidene}amino]ethyl} amine), was designed and synthesized via metal-ion-directed self-assembly with neutral tripodal metalloligands. The formation of this coordination cage was demonstrated by X-ray crystallography, ESI mass spectrometry, FT-IR, and UV-vis-NIR spectroscopy

Functionalization of Pentaphosphorus Cations by Complexation

The chemistry of polyphosphorus cations has rapidly developed in recent years, but their coordination behavior has remained mostly unexplored. Herein, we describe the reactivity of [P5R2]+ cations with cyclopentadienyl metal complexes. The reaction of [CpArFe(μ‐Br)]2 (CpAr=C5(C6H4‐4‐Et)5) with [P5R2][GaCl4] (R=iPr and 2,4,6‐Me3C6H2 (Mes)) afforded bicyclo[1.1.0]pentaphosphanes (1‐R, R=iPr and Mes), showing an unsymmetric “butterfly” structure. The same products 1‐R were formed from K[CpAr] and [P5R2][GaCl4]. The cationic complexes [CpArCo(η4‐P5R2)][GaCl4] (2‐R[GaCl4], R=iPr and Cy) and [(CpArNi)2(η3:3‐P5R2)][GaCl4] (3‐R[GaCl4]) were obtained from [P5R2][GaCl4] and [CpArM(μ‐Br)]2 (M=Co and Ni) as well as by using low‐valent “CpArMI” sources. Anion metathesis of 2‐R[GaCl4] and 3‐R[GaCl4] was achieved with Na[BArF24]. The P5 framework of the resulting salts 2‐R[BArF24] can be further functionalized with nucleophiles. Thus reactions with [Et4N]X (X=CN and Cl) give unprecedented cyano‐ and chloro‐functionalized complexes, while organo‐functionalization was achieved with CyMgCl