A ruthenium(II) complex with p‐cymene and (S)‐2‐(anilinomethyl)pyrrolidine

The title compound, [(S)‐2‐(anilino­methyl)­pyrrolidine‐N,N′]‐chloro(η⁶‐para‐cymene)­ruthenium(II) chloride, [RuCl‐(C₁₀H₁₄)(C₁₁H₁₆N₂)]Cl, has been synthesized by the reaction of [RuCl₂(p‐cymene)]₂ (p‐cymene is para‐iso­propyl­toluene) with (S)‐2‐(anilinomethyl)­pyrrolidine in triethyl­amine/2‐propanol. The Ru atom is in a pseudo‐tetrahedral environment coordinated by a chloride ligand, the aromatic hydro­carbon is linked in a η⁶ manner and the amine is linked via its two N atoms. The chloride anion is involved in hydrogen bonding with the di­amine moieties through N—H?Cl interactions, with N?Cl distances of 3.273 (4) and 3.352 (4) Å.     

Electrospun copper oxide nanoparticles as an efficient heterogeneous catalyst for N-arylation of indole

The N-arylation of indoles with a variety of aryl bromides is reported using copper oxide nanoparticles as a heterogeneous catalyst. These copper oxide nanoparticles, which were produced in a novel, facile, and scalable fashion via an electrospinning technique, resulted in an excellent product yield under mild conditions. Moreover, the catalyst was easily recovered and reused several times without significant loss of activity.     

Gas‐phase copper and silver complexes with phosphorothioate and phosphorodithioate pesticides investigated using electrospray ionization mass spectrometry

Efforts to improve agricultural productivity have led to a growing dependency on organophosphorus pesticides. Phosphorothioate and phosphorodithioate pesticides are organophosphorus pesticide subclasses with widespread application for the control of insects feeding on vegetables and fruits. However, even low doses of these pesticides can cause neurological problems in humans; thus, their determination and monitoring in agricultural foodstuffs is important for human health. Phosphorothioate and phosphorodithioate pesticides may be poorly ionized during electrospray, adversely affecting limits of detection. These pesticides can form complexes with Cu²⁺ and Ag⁺, however, potentially improving ionization. In the present work, we used electrospray ionization/mass spectrometry (ESI/MS) to study fenitrothion, parathion, diazinon, and malathion coordination complexes with silver and copper ions. Stable 1 : 1 and 1 : 2 metal/pesticide complexes were detected. Mass spectra acquired from pesticide solutions containing Ag⁺ or Cu²⁺ showed a significant increase in signal‐to‐background ratio over those acquired from solutions containing only the pesticides, with Ag⁺ improving detection more effectively than Cu²⁺. Addition of Ag⁺ to a pesticide solution improved the limit of detection by ten times. The relative affinity of each pesticide for Ag⁺ was related to complex stability, following the order diazinon > malathion > fenitrothion > parathion. The formation of Ag⁺–pesticide complexes can significantly improve the detection of phosphorothioate and phosphorodithioate pesticides using ESI/MS. The technique could potentially be used in reactive desorption electrospray ionization/mass spectrometry to detect phosphorothioate and phosphorodithioate pesticides on fruit and vegetable skins. Copyright © 2015 John Wiley & Sons, Ltd.     

Theoretical study of the reactions of AlF with HCl: Reaction pathways

The mechanisms for the reactions of AlF with HCl have been characterized in detail using DFT as well as the ab initio method, including zero-point corrections. From the potential energy profile it can be predicted that the reaction process of forming the new Al(III) hydride HAlFCl compound for this reaction is spontaneous with a low activation energy barrier. The reaction yielding to AlFCl₂ and molecular hydrogen was calculated to be highly exothermic. The present calculations also show that the possible routes to the trihalides species start more favorable with the primary insertion products.     

Thiophilic interaction chromatography of serum albumins

An investigation of the binding of native and recombinant human serum albumin and bovine serum albumin on three thiophilic gels, PyS, 2S, and 3S was performed. In addition to these proteins, we studied serum albumins from several species such as goat, rabbit, guinea pig, rat, hamster, baboon, and pig. Our results reveal that recombinant human serum albumin (rHSA) binds completely to PyS whereas native human serum albumin and bovine serum albumin bind only partially to PyS. The binding affinities of rHSA, human serum albumin and bovine serum albumin to 2S and 3S gels are less than their binding to PyS. Serum albumins from goat, rabbit, guinea pig, rat, hamster, baboon, and pig bind much stronger to 3S gel than human and bovine serum albumins. The binding of pig and hamster serum albumins is stronger than that of rat, goat, baboon, and rabbit.     

Novel palladium nanoparticles supported on mesoporous natural phosphate: Catalytic ability for the preparation of aromatic hydrocarbons from natural terpenes

Various ratios of palladium nanoparticles supported on mesoporous natural phosphate (Pd@NP) were prepared using the wetness impregnation method. The prepared catalysts were characterized by IR, XRD, CV, SEM, EDX, XRF, TEM and BET analysis. The reduction and preparation of the palladium nanoparticles afford a crystallite size of 10.88 nm. The performance of the synthesized catalyst was investigated in the solvent-free dehydroaromatization of α-, β- and γ-himachalene mixture from Cedrus atlantica oil as a model substrate. In order to achieve an efficient and selective catalysis, the catalytic dehydroaromatization of various terpenes such as limonene, limonaketone, carvone, carveol and perillyl alcohol was studied. The Pd@NP catalyst performed a high catalytic activity, selectivity and recyclability in the terpenes dehydroaromatization reaction.     

Effect of thermooxidation on tinuvin 783 in LDPE films: Characterization by UV and ftir spectroscopy

The effect of thermooxidation on Tinuvin 783 which is a hindered amine light stabilizer in LDPE films has been investigated by UV and FTIR spectroscopy. Initially, a standard curve describing the variation of the concentration of Tinuvin 783 in LDPE films was plotted using the method of integration of the band area. The relation obtained was: band area = 19.6249 × [Tinuvin 783]. This equation was then applied to measure the variation of the concentration of Tinuvin 783 in the 0.2%_wt stabilized samples which have undergone thermooxidation at 90°C for 98 days. The results showed a considerable decrease in the concentration of Tinuvin 783 by 35% during the first 30 days due to probably the formation of nitroxyl radicals. After this, the concentration was observed to be unchanged and may correspond to the phase of nitroxyl radical regeneration. On the other hand, no chemical change in the stabilized LDPE films was observed by FTIR spectroscopy at 90°C during 98 days while the band characteristic of ketone groups (1720 cm⁻¹) was detected for the unstabilized samples after only 11 days. (LDPE: low density polyethylene; HALS: hindered amine light stabilizer)     

Friedel-Craft acylation of ar-himachalene: synthesis of acyl-ar-himachalene and a new acyl-hydroperoxide

Friedel-Craft acylation at 100 °C of 2,5,9,9-tetramethyl-6,7,8,9-tetrahydro-5H-benzocycloheptene [ar-himachalene], a sesquiterpenic hydrocarbon obtained by catalytic dehydrogenation of α-, β- and γ-himachalenes, produces a mixture of two compounds: (3,5,5,9-tetramethyl-6,7,8,9-tetrahydro-5H-benzocyclohepten-2-yl)-ethanone (2, in 69% yield), with a conserved reactant backbone, and 3, with a different skeleton, in 21% yield. The crystal structure of 3 reveals it to be 1-(8-ethyl-8-hydroperoxy-3,5,5-trimethyl-5,6,7,8-tetrahydronaphthalen-2-yl)-ethanone. In this compound O-H…O bonds form dimers. These hydrogen-bonds, in conjunction with weaker C-H…O interactions, form a more extended supramolecular arrangement in the crystal.     

Theoretical and experimental studies on the carbon-nanotube surface oxidation by nitric acid: interplay between functionalization and vacancy enlargement

The nitric acid oxidation of multiwalled carbon nanotubes leading to surface carboxylic groups has been investigated both experimentally and theoretically. The experimental results show that such a reaction involves the initial rapid formation of carbonyl groups, which are then transformed into phenol or carboxylic groups. At room temperature, this reaction takes place on the most reactive carbon atoms. At higher temperatures a different mechanism would operate, as evidenced by the difference in activation energies. Experimental data can be partially related to first-principles calculations, showing a multistep functionalization mechanism. The theoretical aspects of the present article have led us to propose the most efficient pathway leading to carboxylic acid functional groups on the surface. Starting from mono-vacancies, it ends up with the synergistic formation of dangling -COOH groups and the enlargement of the vacancies.     

Ni(0)-CMC-Na - nickel colloids in sodium carboxymethyl-cellulose: catalytic evaluation in hydrogenation reactions

A recyclable catalyst, Ni(0)-CMC-Na, composed of nickel colloids dispersed in a water soluble bioorganic polymer, sodium carboxymethylcellulose (CMC-Na), was synthesized by a simple procedure from readily available reagents. The catalyst thus obtained is stable and highly active in alkene hydrogenations.