Solvatochromic Probes Absorbance Behavior in Mixtures of 2-Hydroxy Ethylammonium Formate with Methanol, Ethylene Glycol and Glycerol

• DOI: 10.1007/s10953-010-9596-8
• Publication Date: 2010-10-04T18:28:48Z
• Authors: Hadi Salari; Ali Reza Harifi-Mood; Mohammad Reza Ela...; Mohammad Reza Gho...
• Keywords: Solvatochromism; Methyl formate

Solute-solvent and solvent-solvent interactions were investigated for binary mixtures of an ionic liquid (IL) 2-hydroxy ethylammonium formate as with methanol, ethylene glycol and glycerol. The physicochemical properties of the solvent mixtures at 25 °C, over the whole range of mole fractions, were determined using solvatochromic probes. High normal polarity (\(E_{T}^{N}\)) in the alcohol-rich region confirms solute-solvent interactions in this medium. Dipolarity/polarizability (π∗) show a different trend to \(E_{T}^{N}\) with a positive deviation from ideal behavior in IL-glycerol mixtures. However, these deviations for other solvent mixtures are insignificant. Contrary to what is observed for \(E_{T}^{N}\) and π∗, hydrogen-bond donor (HBD) acidity and hydrogen-bond acceptor (HBA) basicity demonstrate similar trends. The applicability of the combined nearly-ideal binary solvent/Redlich-Kister (CNIBS/R-K) equation for the correlation of various parameters provides a simple computational model to correlate and/or predict various solvatochromic parameters for many binary solvent systems.