کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1235815 | 1495281 | 2012 | 6 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: The positive halochromism of phenolate dyes in hydroxylic solutions of tetraalkylammonium cations The positive halochromism of phenolate dyes in hydroxylic solutions of tetraalkylammonium cations](/preview/png/1235815.png)
By contrast with the negative halochromic behaviour shown by phenolate betaines in the presence of alkaline and alkaline-earth cations, the addition of tetraalkylammonium salts to hydroxylic solutions of these dyes generate bathochromic shifts of their charge-transfer band. This positive halochromic behaviour by organic cations was examined systematically and its origin rationalized by nonspecific changes of the medium permittivity, and by specific dye–cation interactions in solution.
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► The halochromic behaviour of tetraalkylammonium salts was investigated in hydroxylic solvents.
► The observed positive halochromism depended on the solvent, and on the dye and cation structures.
► The effect was rationalized by invoking non-specific and/or specific solute–solvent interactions.
► Non-specific effects originate from a decrease of the medium permittivity by addition of the organic salt.
► Specific effects originate from dye–cation interactions, and were simulated with theoretical calculations.
Journal: Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy - Volume 87, 15 February 2012, Pages 61–66