Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1235605 | Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy | 2012 | 5 Pages |
The thermohalochromic behavior of Reichardt’s ET(30) betaine – the temperature-dependent variation of its halochromic band in the presence of a cation – was investigated for the first time in NaI solutions of HBD- (methanol, ethanol, 1-propanol, 1-butanol) and non-HBD-solvents (acetonitrile, dimethylformamide) at 15 and 55 °C. The solvent-dependent thermohalochromism of the pyridinium-N-phenolate betaine dye was interpreted in terms of the effect of the temperature on the dye–cation association in solution.
Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► The halochromism of the ET(30) dye is affected by temperature in what is termed thermohalochromism. ► The phenomenon was studied for the first time in NaI solutions of the ET(30) dye in HBD- and non-HBD-solvents. ► A rise in temperature may increase or decrease halochromic shifts, leading to a positive or negative thermohalochromism. ► The effect depends on the solvent, reflecting salt–dye, solvent–salt and dye–solvent interactions.