01555nas a2200217   4500008004100000022001400041245010400055210006900159260007300228300001200301490000800313520076100321653001601082653001701098653002701115653001801142653001801160653001801178100001601196856012501212       2005                        eng d  a0040-603100aPressure dependence of the dissociation of acetic, benzoic, mandelic and succinic acids at 298.15 K0 aPressure dependence of the dissociation of acetic benzoic mandel  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcDEC  a154-1570 v4393 a<p>Dissociation constants for acetic, benzoic, mandelic and succinic acids have been measured at 298.15 K as a function of pressure up to 138.8 MPa. The spectrophotometric technique using Bromocresol Green as the optical indicator was employed up to ionic strength of 0.03 mol kg(-1) in aqueous solution. Thermodynamic dissociation constants were calculated with the Davies activity coefficient equation. The pressure dependences of the ionization constants for the weak acids can be described by the equation of Lown, Thirsk and Wynne-Jones, application of which leads to accurate partial molal volume change on ionization, Delta(V) over bar (o) and compressibility change, Delta(K) over bar (o) at 0.1 MPa. (C) 2005 Elsevier B.V. All rights reserved.</p>10aAcetic acid10abenzoic acid10adissociation constants10ahigh pressure10amandelic acid10asuccinic acid1 aKumar, Anil  uhttps://library.ncl.res.in/content/pressure-dependence-dissociation-acetic-benzoic-mandelic-and-succinic-acids-29815-k-000945nas a2200181   4500008004100000022001400041245008900055210006900144260011000213300001600323490000700339520022600346100001800572700002300590700001600613700001800629856011600647       2011                        eng d  a1463-907600aProtic ionic liquid attenuates the deleterious actions of urea on alpha-chymotrypsin0 aProtic ionic liquid attenuates the deleterious actions of urea o  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcSEP  a17023-170260 v133 a<p>We present a biocompatible ionic liquid, triethyl ammonium acetate (TEAA), that attenuates the denaturation action of a non-ionic chaotrope, urea, on the industrially relevant proteolytic enzyme alpha-chymotrypsin.</p>1 aAttri, Pankaj1 aVenkatesu, Pannuru1 aKumar, Anil1 aByrne, Nolene  uhttps://library.ncl.res.in/content/protic-ionic-liquid-attenuates-deleterious-actions-urea-alpha-chymotrypsin-001082nas a2200157   4500008004100000022001400041245007000055210006900125260007100194300001400265490000700279520050800286100001700794700001600811856009700827       2012                        eng d  a0022-326300aProbing the mechanism of baylis-hillman reaction in ionic liquids0 aProbing the mechanism of baylishillman reaction in ionic liquids  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcOCT  a8775-87790 v773 a<p>The kinetic data for a Baylis-Hillman reaction in certain ionic liquids possessing ethylsulfate anion [EtSO4](-) demonstrate that the rate determining step (RIDS) is second order in aldehyde, but first order in acrylate and DABCO. This observation is similar to the one made by McQuade et al., who carried out this reaction in an aprotic polar solvent like DMSO. However, this is in contrast to the general observation that ADS is first order in aldehyde, acrylate, and DABCO in organic solvents.</p>1 aSingh, Anshu1 aKumar, Anil  uhttps://library.ncl.res.in/content/probing-mechanism-baylis-hillman-reaction-ionic-liquids-001300nas a2200217   4500008004100000022001400041245007400055210006900129260007700198300001400275490000700289520055100296653001600847653002300863653001800886653002000904653002000924100001900944700001600963856010300979       2012                        eng d  a1439-423500aProbing thermal interactions of ionic liquids with dimethyl sulfoxide0 aProbing thermal interactions of ionic liquids with dimethyl sulf  aBOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcMAY  a1927-19330 v133 a<p>Interactions between ionic liquids and dimethyl sulfoxide (DMSO) are probed by isothermal titration calorimetry. The excess partial molar enthalpies of ionic liquids H-IL(E) in DMSO are discussed in terms of solutesolvent interactions. The specific interaction theory originally developed by Pitzer is used to analyze the apparent molar enthalpy phi(L) of ionic liquids in DMSO with the help of ion-interaction parameters. Furthermore, quantitative information on solvent reorganization and clathrate formation is obtained and interpreted.</p>10acalorimetry10adimethyl sulfoxide10aionic liquids10asolvent effects10athermochemistry1 aRai, Gitanjali1 aKumar, Anil  uhttps://library.ncl.res.in/content/probing-thermal-interactions-ionic-liquids-dimethyl-sulfoxide-002185nas a2200157   4500008004100000022001400041245014000055210006900195260007100264300001400335490000800349520150200357100002501859700001601884856012701900       2013                        eng d  a1520-610600aProbing the acidity of carboxylic acids in protic ionic liquids, water, and their binary mixtures: activation energy of proton transfer0 aProbing the acidity of carboxylic acids in protic ionic liquids   a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcFEB  a2456-24650 v1173 a<p>Acidity functions 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 acidity function, H-0. A reversal in the acidity trend was observed, when organic acids were transferred from water to PIL. It was emphasized that an increased stabilization offered by PIL cation toward the more basic conjugate anion of organic acid was responsible for this anomalous change in acidity order in PILs, which was absent in water. The greater stabilization of a basic organic anion by PIL cation is discussed in terms of the stable hard-soft acid base (HSAB) pairing. A change in the H-0 values of these acids was observed with a change in temperature, and a linear correlation between the ln H-0 and 1/T was noted. This relationship points toward the activation energy of proton transfer (E-a,E-H+), a barrier provided by the medium during the proton transfer from Bronsted acid to indicator. The H-0 function in binary mixtures points to the involvement of pseudosolvent, the behavior of which changes with the nature and concentration of acid. The presence of the maxima/minima in the H-0 function is discussed in terms of the synergetic behavior of the pseudosolvent composed of the mixtures of aqueous PILs.</p>1 aShukla, Shashi, Kant1 aKumar, Anil  uhttps://library.ncl.res.in/content/probing-acidity-carboxylic-acids-protic-ionic-liquids-water-and-their-binary-mixtures-003050nas a2200157   4500008004100000022001400041245020500055210006900260260007100329300001400400490000800414520231200422100001602734700001602750856012602766       2015                        eng d  a1520-610600aPhase behavior, diffusion, structural characteristics, and pH of aqueous hydrophobic ionic liquid confined media: insights into microviscosity and microporsity in the [C(4)C(4)im][NTf2] + water system0 aPhase behavior diffusion structural characteristics and pH of aq  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcJAN  a1641-16530 v1193 a<p>We present our studies on the physicochemical properties of water confined in Dibutylimidazolium bis(trifluoromethanesulfonylimide) ([C(4)C(4)im][NTf2]) reverse micelles through the NMR relaxation measurements that provide us an understanding of microviscosity and pH in the confined condition. We present experimental results on phase behavior, diffusion, structural characteristics and pH in aqueous ionic liquid-confined media. The ternary phase diagram was constructed by the cloud point measurements and the microheterogeneous regions were detected by the measurement of bulk viscosity and diffusion coefficients of K-4[Fe(CN)(6)] inside the homogeneous microemulsion systems through the cyclic voltammetric (CV) measurements. The size of the microemulsion systems was characterized by the dynamic light scattering (DLS) method. The H-1 NMR spectra of homogeneous microemulsion systems were taken which indicates the presence of bound and free water molecules inside the microemulsion system. The NMR spinlattice relaxation time (T-1) of water molecules in its homogeneous microemulsion systems were measured and the reorientational correlation time (t(c)) of water molecules obtained from it indicates that the fluidity of homogeneous confined media decreases with the decrease in the composition of water. Microviscosity of the aqueous confined media was calculated from the measured T-1 relaxation time values by applying the DebyeStokes equation and correlated with the bulk viscosity of the samples. It was observed that both the microviscosity and bulk viscosity show inverse relationship. The fraction of bound and free water molecules were calculated from the measured T-1 values. NMR spinspin relaxation time (T-2) of water molecules in its homogeneous microemulsion systems were measured with the varying pH of the aqueous core. A change in the T-2 relaxation time of the water proton was observed proposing an exchange of proton between the H2O and -OH group of the TX-100 molecules. Finally, methyl orange (MO) was used as a UVvis spectrophotometric molecular probe and the measured lambda(max) values of the probe were used for the detection of micropolarity of the homogeneous aqueous confined media and was found to be increase with the increase in the size of the confined media.</p>1 aNanda, Raju1 aKumar, Anil  uhttps://library.ncl.res.in/content/phase-behavior-diffusion-structural-characteristics-and-ph-aqueous-hydrophobic-ionic-101243nas a2200157   4500008004100000022001400041245005400055210005400109260005700163300001400220490000700234520071500241100002500956700001600981856008800997       2015                        eng d  a1618-954X00aPolarity issues in room temperature ionic liquids0 aPolarity issues in room temperature ionic liquids  a233 SPRING ST, NEW YORK, NY 10013 USAbSPRINGERcAPR  a1111-11160 v173 a<p>The study on ionic liquids has occupied an important place in chemical processes because of several beneficial properties. In order to use these ionic liquids as solvent media in chemical processes, it is essential to know their solvent properties. In this review, an attempt has been made to critically evaluate and discuss the polarity parameters of ionic liquids. The experimental polarity data on ionic liquids are not yet available for numerous ionic liquids. This review will serve as a guideline to investigate polarity issues of these materials and emerge with a simple, but still sound theoretical or semi-empirical models to account for the variation in polarity in the ionic liquid solutions.</p>1 aShukla, Shashi, Kant1 aKumar, Anil  uhttps://library.ncl.res.in/content/polarity-issues-room-temperature-ionic-liquids-002107nas a2200145   4500008004100000245015400041210006900195260000800264300001200272490000800284520151200292100001701804700001601821856012401837       2017                        eng d00aProbing the solute-solvent interactions in the binary mixtures of ionic liquids with water and alcohols by conductance, viscosity and IR spectroscopy0 aProbing the solutesolvent interactions in the binary mixtures of  cJUL  a270-2800 v2383 aThe molar conductance and viscosities of the bisulfate ([HSO4](-)) and ethylsulfate ([EtSO4](-))-based imidazolium ionic liquids in various molecular solvents have been measured at 298.15 K as a function of concentration of ionic liquids (1 x 10(-4) to 0.1 mol L-1). It is shown that the anions have considerable effect on the molar conductance and association constant of the [HSO4](-) and [EtSO4](-)-based imidazolium ionic liquids. Higher molar conductance of the [HSO4](-)-based imidazolium ionic liquids in polar protic solvents (water and methanol) is noted as compared to the [EtSO4](-)-based imidazolium ionic liquids, though the [HSO4](-)-based imidazolium ionic liquids possess higher association constant in water than in methanol. The intermolecular interactions in the pure and binary mixture of [HSO4](-) and [EtSO4](-)-based imidazolium ionic liquids have been investigated by IR spectroscopy. The C-2-H stretching vibration frequency of the imidazolium ring reveals the H-bonding between cations and anions of pure ionic liquids and their solutions. The transport properties (limiting molar conductance, transport number, ionic mobility and diffusion coefficient) of cations and anions correlate well with the hydrodynamic radius in their aqueous solutions. The study shows that the energy barrier for charge transfer is minimal as compared to the fluidity of the aqueous solution of the studied ionic liquids obtained from the Arrhenius equation. (C) 2017 Elsevier B.V. All rights reserved.1 aJain, Preeti1 aKumar, Anil  uhttps://library.ncl.res.in/content/probing-solute-solvent-interactions-binary-mixtures-ionic-liquids-water-and-alcohols