Probing the Acidity of Carboxylic Acids in Protic Ionic Liquids, Water, and Their Binary Mixtures: Activation Energy of Proton Transfer
作者:Shashi Kant Shukla、Anil Kumar
DOI:10.1021/jp310927w
日期:2013.2.28
Acidityfunctions were used to express the ability of a solvent/solution to donate/accept a proton to a solute. The present work accounts for the acidity determination of HCOOH, CH3COOH, and CH3CH2COOH in the alkylimidazolium-based protic ionic liquids (PILs), incorporated with carboxylate anion, water, and in a binary mixture of PIL and water using the Hammett acidityfunction, H0. A reversal in the
Simple protic ionic liquid [Et3NH][HSO4] as a proficient catalyst for facile synthesis of biscoumarins
作者:Sandip K. Patil、Deepak V. Awale、Madagonda M. Vadiyar、Suryakant A. Patil、Sagar C. Bhise、Sanjay S. Kolekar
DOI:10.1007/s11164-017-2932-5
日期:2017.10
Abstract We have explored a number of protic ionicliquids (PILs) as a catalyst for the synthesis of biscoumarins by condensation of 4-hydroxycoumarin with an aromatic aldehyde. Methylimidazolium- and triethylammonium-based PILs were synthesized by simple neutralization reaction with protic acids. Triethylammoniumhydrogensulfate [Et3NH][HSO4] was found to be the best among the studied PILs concerning
wide range of pKa differences (ΔpKa) between the parent acid and base molecules were thermally evaporated in vacuum, trapped on a CsI plate by a cryogenic neon matrix-isolation method, and studied by Fourier transform infraredspectroscopy and density functional theory calculations. The parent neutral molecules and proton-transferred cation–anion pair species were identified as chemical components
Halogen-Free Room-Temperature Brønsted Acidic Ionic Liquid [Hmim]<sup>+</sup> HSO<sub>4</sub> <sup>−</sup> as a Recyclable Green “Dual Reagent” Catalysis for the Synthesis of Triarylmethanes (TRAM<scp>s</scp>)
halogen-free Brønstedacidicionicliquid methylimidazolium hydrogen sulfate ([Hmim]+ HSO4 −) acts as a very efficient catalyst for the one-pot, two-component Baeyer condensation of a variety of aromatic aldehydes with dimethyl or diethyl aniline at room temperature. This “green” reagent behaves as both catalyst and solvent; that is, it exhibits “dual-reagent catalysis.” The room-temperature acidicionic liquid
Do anions influence the polarity of protic ionic liquids?
作者:Shashi Kant Shukla、Nageshwar D. Khupse、Anil Kumar
DOI:10.1039/c2cp23256a
日期:——
value for PILs varies inversely to the strength of the coulombic interaction betweenions in PILs. Strong interactions betweenions lead to lower ET(30) values. Unlike the poor thermal effect on ET(30), the Kamlet–Taft parameters i.e. α, β and π* have pronounced thermal effect in the imidazolium-based PILs. Variation in the Kamlet–Taft parameters is controlled by the stabilization of ions and the degree