Solute–solvent and solvent–solvent interactions in the preferential solvation of Brooker's merocyanine in binary solvent mixtures

Abstract

The E T polarity values of 4-[(1-methyl-4(1H)-pyridinylidene)ethylidene]-2,5-cyclohexadien-1-one, better known as Brooker's merocyanine, were collected in binary mixtures comprising a non-protic [acetonitrile, dimethyl sulfoxide (DMSO) and acetone] and a protic (water, methanol, ethanol, propan-2-ol and butan-1-ol) solvent. Data referring to mixed systems involving water and alcohols (methanol, ethanol, propan-2-ol and 2-methylpropan-2ol) were also collected. These data were used in the investigation of the preferential solvation of the dye. Each solvent system was analyzed in terms of both solute-solvent and solvent-solvent interactions. These latter interactions are responsible for the synergistic effects observed for the E T parameter in many binary mixtures. All data were successfully fitted to a model based on solvent exchange equilibria, which allowed the separation of the different contributions of the solvent species in the solvation shell of the dye. This model was then successfully applied to explain the kinetic behavior of the methylation of sodium 4-nitrophenoxide in acetone-water mixtures. This result suggests that this solvatochromic strategy can be successful in the analysis of many other solvent-dependent kinetic and thermodynamic processes occurring in mixed solvents.

Solubility of Stevioside and Rebaudioside A in water, ethanol and their binary mixtures

“…Similar values of ED(30) were estimated for binary mixtures with 30% of water (53.7 Kcal/mol) and 70% of water (53.0 Kcal/mol). These results are consistent with the behavior observed before with these binary solvents from 30% to 70% of ethanol (da Silva, Ricken, Silva, & Machado, 2002). (tetramethylsilanethe) to 1.000 for the most polar solvent (water); with a value of 0.654 for ethanol (Reichardt, 2004b).…”

Low‐Voltage Transistor Employing a High‐Mobility Spin‐Coated Chalcogenide Semiconductor

“…While the use of mixed non-aqueous solvents has not been extensively explored in chalcogenide solution chemistry, improvement in solubility for mixed solvents might be expected based on the possibility of synergistic solvent±solvent and solvent±ion interactions. [21,22] Dipolar aprotic DMSO has proven to be very effective as a solvent for water-insoluble compounds and is commonly used as a vehicle for drug delivery. [23] The mildly alkaline protic solvent ethanolamine offers a combination of properties of its two functional groups (amine and alcohol).…”

Photophysical properties of a surfactive long-chain styryl merocyanine dye as fluorescent probe

“…Such type of solvatochromism is detected in polymethine dye chromophores, which can reach the ideal polymethine state in weakly polar solvent [61]. Similar phenomena have been observed for other dyes also [62][63][64][65], where the replacement of solvents with low polarity by highly polar solvent, or vice versa, leads to a deviation from the ideal polymethine state and changes the energy of the electronic transition. It should be noted that the study of dye are salts, and in polar solvents may be in the form of dissociation, to form ionic complexes between the cation dye, its anion and solvent molecules which manifest themselves in the absorption spectra as a bathochromic or hypsochromic shifts [66].…”