Search results for "Azolium"

The Gelling Ability of Some Diimidazolium Salts: Effect of Isomeric Substitution of the Cation and Anion

2013

The gelling ability of some geminal imidazolium salts was investigated both in organic solvents and in water solution. Organic salts differing either in the cation or anion structure were taken into account. In particular, the effects on the gel-phase formation of isomeric substitution on the cation or anion as well as of the use of mono- or dianions were evaluated. As far as the cation structure is concerned, isomeric cations, such as 3,3′-di-n-octyl-1,1′-(1,4-phenylenedimethylene)diimidazolium and 3,3′-di-n-octyl-1,1′-(1,3-phenylenedimethylene)diimidazolium, were used. On the other hand, in addition to the bromide anion, isomeric dianions, such as the 1,5- and 2,6-naphthalenedisulfonate a…

Ultrasonic and Volumetric Properties of 1-Ethyl-3-methylimidazolium Trifluoromethanesulfonate Ionic Liquid with 2-Propanol or Tetrahydrofuran at Seve…

2011

Densities and speeds of sound of 1-ethyl-3-methylimidazolium trifluoromethanesulfonate mixtures with 2-propanol and tetrahydrofuran (THF), as well as of the pure components, have been measured over the whole range of compositions at T = (278.15 to 328.15) K and P = (101 ± 2) kPa. From these experimental data, the excess molar volume, excess speed of sound, and excess isentropic compressibility have been calculated and fitted to an extended version of the Redlich–Kister equation, which takes into account the dependence on composition and temperature simultaneously. The Prigogine–Flory–Patterson theory has also been used to explain the behavior of these systems.

Bis(imidazolium) salts derived from amino acids as receptors and transport agents for chloride anions

2015

The binding properties of bis(imidazolium) hosts 1a–c derived from amino acids towards different anions have been studied by 1H NMR titration experiments in 95 : 05 CD3CN : H2O at 303 K, ESI-MS and theoretical calculations. Among this family, the salt 1c showed a strong and high selectivity for chloride anions. Transmembrane chloride transport activity has also been studied for the three bis(imidazolium) based transporters in POPC liposome models, and compound 1a was identified as an active chloride/nitrate exchanger.

Insights into the anion effect on the self assembly of perylene bisimide diimidazolium salts

2017

Abstract We studied how changing the anion affects the self-assembly of three diimidazolium salts bearing a perylene bisimide spacer. In particular we used [BF 4 − ] and [NTf 2 − ] based salts together with a mixed salt bearing both [I − ] and [BF 4 − ] anions. Thermal as well as concentration and temperature dependent spectroscopic investigations revealed that changing the anion impacts on solid state and solution aggregation, leading to articulate thermotropic behaviors and contrasting solvent effects, respectively. We also studied the electrochemical behavior of the salts to verify if changing the anion alters the redox properties of the salts. Finally, different anions also lead to very…

Thiazolium-­‐based catalysts for the etherification of benzylic alcohols under solvent-­free conditions

2015

In this work, thiazolium and imidazolium hybrid materials (SBA-15-Thia and SBA-15-Imi) were prepared by grafting the bis-vinylthiazolium or imidazolium salts onto thiol functionalized SBA-15 mesostructured silica. The catalytic activity was tested for the etherification of 1-phenylethanol, in heterogeneous conditions. The reactions were performed under different gas phases and reaction times. The SBA-15-Thia displayed an excellent catalytic performance, also with others benzyl alcohols. This material was successfully used in seven consecutive runs. Further studies were carried out in homogenous conditions. The results obtained allow proving that oxygen play an active role in the reaction pr…

Nanoscopic hybrid systems with a polarity-controlled gate-like scaffolding for the colorimetric signalling of long-chain carboxylates

2007

Hybrid mesoporous systems containing a gate-like ensemble functionalised with imidazolium groups and a dye are used for the selective colorimetric sensing of long-chain carboxylates. Amoros del Toro, Pedro Jose, Pedro.Amoros@uv.es

Morphology of experimentally denervated and reinnervated rat facial muscle I. Histochemical and histological findings

1994

The morphological changes in rat facial muscles were evaluated after permanent denervation and were compared with findings after immediate reinnervation. Thirty rats underwent transection of the left and right facial nerves immediately followed by hypoglossal-facial nerve anastomosis on the right side (muscular reinnervation) and removal of 8-10 mm of the facial plexus on the left side (permanent muscular denervation). Levator labii muscle samples of both sides were collected sequentially at 2, 6, 7, 10, 20, and 24 weeks after surgery and submitted to routine histological and enzyme histochemical staining procedures. In normal levator labii muscles a typical "chessboard" pattern was found, …

DESIGN OF NOVEL IMIDAZOLIUM BASED NANOSTRUCTURES FOR SUSTAINABLE CATALYTIC APPLICATIONS

New “AIE” Luminogens based on π-conjugated imidazolium salts

Hemin-coupled iron(III)-hydroxide nanoparticles show increased uptake in Caco-2 cells

2011

Abstract Objectives The absorption of commonly used ferrous iron salts from intestinal segments at neutral to slightly alkaline pH is low, mainly because soluble ferrous iron is easily oxidized to poorly soluble ferric iron and ferrous iron but not ferric iron is carried by the divalent metal transporter DMT-1. Moreover, ferrous iron frequently causes gastrointestinal side effects. In iron(III)-hydroxide nanoparticles hundreds of ferric iron atoms are safely packed in nanoscaled cores surrounded by a solubilising carbohydrate shell, yet bioavailability from such particles is insufficient when compared with ferrous salts. To increase their intestinal uptake iron(III)-hydroxide nanoparticles …