01747nas a2200169   4500008004100000022001400041245009800055210006900153260007100222300001400293490000700307520107100314100002201385700002601407700001601433856012801449       2008                        eng d  a0022-326300aIntramolecular Diels-Alder reaction in ionic liquids: effect of ion-specific solvent friction0 aIntramolecular DielsAlder reaction in ionic liquids effect of io  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcNOV  a9075-90830 v733 a<p>The present work aims at understanding the role of viscosity or solvent friction in ionic liquids for an intramolecular Diels-Alder (IMDA) reaction of (E)-1-phenyl-4-[2-(3-methyl-2-butenyloxy)benzylidene]-5-pyrazolone (1). The results have been analyzed on the basis of the current theoretical models, and their failure to account for the observed trends is discussed in terms of ``effective'' viscosity or microviscosity. The rates of the reaction decrease with the increasing viscosity of the ionic liquids. As evident from the anionic effect, the solute-solvent specific interactions play a role in governing the kinetics of the reaction. The lower viscosities of the bistrifluoromethanesulfonimide [NTf(2)](-) based ionic liquids as compared to those based on tetrafluoroborate [BF(4)](-) anion fail to result in a corresponding acceleration in the rates of the reaction. These contradictory results indicate that solvent microviscosity, rather than the bulk macroscopic viscosity, should be the criteria for selecting the ionic liquids as reaction media.</p>1 aTiwari, Shraeddha1 aKhupse, Nageshwar, D.1 aKumar, Anil  uhttps://library.ncl.res.in/content/intramolecular-diels-alder-reaction-ionic-liquids-effect-ion-specific-solvent-friction-001433nas a2200157   4500008004100000022001400041245009300055210006900148260007100217300001600288490000800304520081500312100002201127700001601149856011001165       2009                        eng d  a1089-563900aInterfacial reactivity of ``on water'' reactions in the presence of alcoholic cosolvents0 aInterfacial reactivity of on water reactions in the presence of   a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcDEC  a13685-136930 v1133 a<p>A detailed study of the variation in the interfacial reactivity and selectivity of ``on water'' reactions in the presence of increasing amounts of alcoholic cosolvents is discussed in the present work. The initial increase in the rates of ``on water'' reactions on the addition of alcoholic cosolvents is contrary to the sharp decrease in rates observed for homogeneous aqueous reactions. The existing theoretical framework is presented in terms of a typical ``on water'' process to enable a discussion of the experimental observations with reference to changing composition of the reaction medium. On the basis of the interesting observations of reactivity and selectivity variations with composition of the reaction medium, a simple ``signature'' characteristic for ``on water'' reactions is proposed.</p>1 aTiwari, Shraeddha1 aKumar, Anil  uhttps://library.ncl.res.in/content/interfacial-reactivity-water-reactions-presence-alcoholic-cosolvents-0