Solvatochromic parameters for solvents of interest in green chemistry

Abstract

Solvatochromic data have been collected from the literature or newly measured for 83 molecular solvents, 18 switchable solvents, and 187 ionic liquids that have been cited in the green chemistry literature. The data include the normalized Reichardt's parameter (E N T ), the Nile red λ max , and the Kamlet-Taft parameters (α, β, and π*). Disagreements within the literature about the properties of glycerol and poly (ethylene glycol) have been resolved with new data. The switching of a switchable-polarity solvent (also known as a reversible ionic liquid) by CO 2 causes a significant increase in polarity/polarizability (π*) but no change in the basicity (β). A switchable-hydrophilicity solvent undergoes an even greater change in polarity because it merges with an aqueous phase upon exposure to CO 2 . Trends observed from the data of ionic liquids are presented, along with concerns about the best method for determining the Kamlet-Taft parameters.

Hydrogen-bond acidity of ionic liquids: an extended scale

“…The KT solvatochromic parameters were determined for the [ 52 The purities of all ILs were further checked by 1 H, 13 C, and 19 F NMR and were shown to be higher than 98 wt%.…”

“…13,15,17,[22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][47][48][49][50][51] It should be highlighted that the hydrogen-bond acceptor strength of an IL is dominated by its anion while the hydrogen-bond donor ability is essentially controlled by the cation and only slightly depends upon the anion of the IL. 18,19 Thus, and since we were focused on developing an extended series for the hydrogen-bond acidity of ILs, ILs comprising a fixed anion ([NTf 2 ] − ) and a wide range of cations (imidazolium-, pyridinium-, piperidinium-, pyrrolidinium-, ammonium-, sulfonium-, and phosphonium-based) were selected. The [NTf 2 ]-based ILs were also chosen because most of them are liquid at room temperature, thus allowing the study of a broad range of IL cations and their impact on the IL hydrogen-bond acidity.…”

Unimolecular Solvolyses in Ionic Liquid: Alcohol Dual Solvent Systems

“…Comparing these slopes can therefore tell us much about how different solvent systems affect the preferred solvolysis pathway. Slopes are summarized in Table 1 along with the Kamlet-Taft solvatochromic parameters for hydrogen bond donating and accepting ability, α and β, respectively [17]. As ILs tend to be hygroscopic to varying degrees, great care was taken to ensure that each IL used be extremely dry.…”

Application of Ionic Liquid based Microwave-Assisted Extraction of the Secondary Metabolite from Peperomia pellucida (L) Kunth

“…Moreover, can consider as the constituents potential to replace organic solvents that are flammable, volatile and toxic while solvent ionic liquid has the opposite properties. 2 Some previous study has been applied an ionic liquid for extraction of the target compound from plants such us trans-resveratrol from Polgonum cuspidatum Sieb. et.…”