Showing papers in "Green Chemistry in 2003"

TL;DR: In this paper, a decomposition product created during purification of the hydrophobic ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate was identified.

TL;DR: In this paper, the authors present an account of their research into ionic liquids from the perspective of a future, large-scale producer of ionic liquid for industrial applications, and broad comparisons are made to relevant imidazolium systems.

TL;DR: Ionic liquids are shown to display anti-microbial activity with the activities being greatly affected by alkyl chain lengths, and the use of microorganisms in the IL require consideration of their minimum inhibitory concentration (MIC) values.

TL;DR: In this paper, the authors present a review of recent developments on the epoxidation of alkenes using hydrogen peroxide as an environmentally friendly oxidant in the presence of a homogeneous metal catalyst such as tungten, manganese, iron and rhenium.

TL;DR: Experiments have indicated that [bmim]Cl, and several other ILs, as well as dimethylacetamide–LiCl (a well-known solvent system for cellulose), inactivate cellulase under these conditions.

TL;DR: Asahi Kasei as discussed by the authors developed a new green process for producing an aromatic polycarbonate based on bisphenol-A without using phosgene and methylene chloride.

TL;DR: In this article, the results for the dehydration of D-fructose to 5-hydroxymethylfurfural (HMF) in sub-and supercritical acetone are presented.

TL;DR: In this article, a strategy for an environmental risk assessment of chemicals, using a combination of structure-activity relationships (SAR), toxicological and ecotoxicological tests and modelling, is presented.

TL;DR: In this paper, carboxylic acids with alcohols were used for esterification in a Bronsted acidic ionic liquid 1-methylimidazolium tetrafluoroborate ([Hmim]+BF4−).

TL;DR: In this paper, the densities and viscosities for mixtures of 1-n-butyl-3-methylimidazolium tetrafluoroborate ionic liquid with acetonitrile, dichloromethane, 2-butanone and N,N-dimethylformamide have been determined at 298.15 K.

TL;DR: In this paper, the authors extracted sulfur-containing compounds from light oils by a combination of both chemical oxidation and solvent extraction using the room temperature ionic liquids (RTILs), 1-butyl-3-methylimidazolium hexafluorophosphate (BMIM+PF6−) and 1- butyl- 3methyloridazolate tetrafluoroborate (BF4−), and then S-oxidized them to form corresponding sulfones.

TL;DR: The predominant mode of strontium ion transfer from acidic nitrate media into a series of 1-alkyl-3-methylimidazolium-based room-temperature ionic liquids containing dicyclohexano-18-crown-6 (DCH18C6) shifts from cation exchange to stontium nitratocrown ether complex partitioning as the hydrophobicity of the ionic liquid cation is increased.

TL;DR: In this article, the effects of anion type, C-2 hydrogen substitution, and alkyl chain length on the flammability, thermal stability, and phase change characteristics of 1,2,3-trialkylimidazolium room temperature ionic liquids were investigated.

TL;DR: The world's first, multi-reaction, supercritical flow reactor was commissioned in 2002 as a direct result of the successful collaboration between the Clean Technology Group at the University of Nottingham and the fine chemicals manufacturer, Thomas Swan & Co. Ltd as discussed by the authors.

TL;DR: Ionic liquids of the 1,3-dialkylimidazolium type reveal great potential for the innovative application of microwaves for synthesis as well as for separations as mentioned in this paper.

TL;DR: In this paper, a controlled, multimode microwave irradiation has been employed in a generic solvent-free process to prepare a wide range of ionic liquids based on nitrogen-containing heterocycles.

TL;DR: In this article, a novel silica supported palladium catalyst has been prepared and investigated for the Suzuki cross-coupling reaction between aryl bromides and benzeneboronic acid in the presence of K2CO3 as base and o-xylene as solvent.

TL;DR: In this paper, a review explores how miniaturisation may revolutionise chemical synthesis, highlighting in particular the environmental benefits of this new technology, which include solvent free mixing, in situ reagent generation and integrated separation techniques.

TL;DR: In this paper, the synthesis of 2-phenylbenzimidazole from 1,2-phenylonenediamine and benzoic acid was chosen as a benchmark reaction and the reaction parameters, such as temperature, density and reaction time, were systematically studied to understand whether the solvent properties of high-temperature water can have a positive effect on the chemistry.

TL;DR: In this article, the effect of various reaction variables on the activity and selectivity performance on a two-step synthesis of dimethyl carbonate (DMC) and glycol from propylene oxide, carbon dioxide and methanol using a heterogeneous Mg containing smectite catalyst was reported.

TL;DR: A new efficient gold(III) catalysed synthesis of β-enaminones from 1,3-dicarbonyl compounds and ammonia/amines providing an attractive and environmental friendly alternative to the more vigorous reagents and drastic conditions of the existing methodologies is described.

TL;DR: In this article, the authors used the Quantitative Structure-Property Relationship (QSPR) method to correlate and predict the melting points of organic salts based on the quaternary ammonium cation.

TL;DR: In this paper, the Rf3RPI catalyst was used for catalyzed propylene carbonate synthesis from propylene oxide and carbon dioxide under supercritical CO2 conditions, where the carbonate was spontaneously separated out of the super-critical CO 2 phase.

TL;DR: New room temperature ionic liquids based on the tetra-alkyl-dimethylguanidinium cation present high stability under thermal, basic, acid, nucleophilic and oxidative conditions, low temperature glass transition phases and peculiar solubility properties in common solvents.

TL;DR: In this paper, a room temperature ionic liquid containing a bis-imidazolium cation incorporating a short ethylene-glycol spacer was prepared from the corresponding chloride salt, and the X-ray crystal structure of the lowmelting hexafluorophosphate salt has been determined.

TL;DR: In this paper, the authors present the optimisation of the oxidative steam reforming of ethanol for hydrogen production in order to feed a Solid Polymer Fuel Cell (SPFC) over a Ni-Cu/SiO2 catalyst at on-board conditions.

TL;DR: In this paper, a homogeneously-catalyzed asymmetric hydrogenation of α,β-unsaturated carboxylic acids was chosen for its economic interest and its multiple H2-concentration dependent behaviours.

TL;DR: Clean synthesis to imidazolidone and oxazolidon compounds using direct reaction of carbon dioxide with diamine or amino alcohols can be achieved at 6 MPa CO2 and 150 °C without use of any catalyst as discussed by the authors.

TL;DR: A CaO/C composite, a new solid base catalyst, was prepared and served as a convenient and efficient heterogeneous catalyst for synthesis of DMC from methanol and propylene carbonate as discussed by the authors.

TL;DR: In this article, two-step synthesis of dimethyl carbonate from urea has been investigated with various solid catalysts, and it has been found that ZnO is highly active and selective for the two steps, of which the former should be conducted under reduced pressure.