Search results for "ionic liquid"
showing 10 items of 432 documents
NMR Spectroscopic characterization and thermal behaviour of a new class of dicationic imidazolium ionic liquids
Miscela binaria liquido ionico/[bmim][N3]: un mezzo efficace per la sintesi di arilazidi mediante SNAr
Acidic imidazolium salts: catalysts for biomass transformation
Gluconic acid for eco-friendly Ionic Liquids: chemical and biological investigations
Ionic liquids (ILs) are employed in several fields thanks to their well-known properties. For a long time, ILs were considered the “green” alternative to conventional organic solvents.1 However, the increasing attention on environmental health led to consider different ILs structures and alternative synthetic pathways. Considering the tunability of IL structures, new synthetic approaches with natural sources as starting materials were taken into account.2 Here, new eco-friendly ILs were synthesised using gluconic acid. The structures carry gluconic moiety on the cation or as the anion (Figure 1). Hence, several OH groups decrease toxicity and shape a high coordinative site. These new organi…
SYNTHESIS OF OXADIAZOLE BASED ORGANIC SALTS
2010
Organocatalizzatori e liquidi ionici supportati: nuovi materiali in sintesi organica
2011
Nell’ultimo decennio l’organocatalisi e i liquidi ionici hanno rappresentato due campi di grande interesse scientifico. Gli organocatalizzatori hanno trovato particolare impiego in sintesi enantioselettive conducendo a prodotti finali con alte rese e selettività. I liquidi ionici sono stati estensivamente utilizzati come solventi alternativi e, opportunamente modificati, come catalizzatori o loro supporti. Uno sviluppo attuale che accomuna questi due campi di ricerca consiste nella possibilità di immobilizzazione di organocatalizzatori e liquidi ionici per trasformarli in materiali riciclabili con ampie capacità di utilizzo in chimica organica. Negli ultimi anni, il nostro gruppo di ricerca…
Functionalised Imidazolium Dicationic Ionic Liquids used as reaction media for base catalyzed organic reactions
Effects of shear flow on the structure and dynamics of ionic liquids in a metallic nanoconfinement.
2021
It has been shown that a weak shear can induce crystallisation in a disordered, glassy state. In this study, we use molecular dynamics simulations in order to investigate the out-of-equilibrium properties of [BMIM][BF4] confined between metal slabs. In particular, we want to understand the extent to which the shear flow modifies the interfacial properties. In particular, the questions we address here are (i) is the shear able to promote the crystalline phase in [BMIM][BF4]? (ii) Can, as a consequence of shear flow, a solid-like layer develop at the interface with a metallic surface? (iii) What are the tribological properties of nanoconfined [BMIM][BF4]? We find that the system behaves quite…
Secondary Chemical Equilibria in Reversed-Phase Liquid Chromatography
2013
The addition of reagents to an RPLC mobile phase enables the separation of ionizable compounds, inorganic anions, and metal ions using conventional instrumentation, silica-based materials, and hydro-organic mixtures, thanks to a variety of secondary equilibria. This gives rise to several chromatographic modes, whose main features are outlined in this chapter. The effect of the mobile phase pH on the retention of ionizable compounds is described, together with the recommended experimental practice. The mechanism of adsorption of amphiphilic anions or cations on the stationary phase to attract analytes with opposite charge or suppress the silanol activity is discussed. Different reagents, suc…
Supported ionic liquids. New recyclable materials for the L-proline-catalyzed aldol reaction
2006
New materials for L-proline recycling have been developed. These materials have been applied to the L-proline-catalyzed aldol reaction between acetone and several aldehydes. The L-proline has been supported on the surface of modified silica gels with a monolayer of covalently attached ionic liquid with or without additional adsorbed ionic liquid. Good yields and ee values, comparable with those obtained under homogeneous conditions, have been obtained especially with imidazolinium-modified and 4-methylpyridinium-modified silica gels. Moreover, these materials have been easily recovered by simple filtration and studies about their reuse have been carried out. These studies showed that these …