title: The positive halochromism of phenolate dyes in hydroxylic solutions of tetraalkylammonium cations.
abstract: 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.
authors.affiliation: Facultad de Química y Biología, Universidad de Santiago, Av. B.O'Higgins 3363, Santiago, Chile. marcos.caroli@usach.cl
authors.forename: Marcos Caroli
authors.initials: MC
authors.lastname: Rezende
authors.forename: Moisés
authors.initials: M
authors.lastname: Dominguez
authors.forename: Andrés
authors.initials: A
authors.lastname: Aracena
mesh_terms: D001622:Betaine / Q000737:chemistry*; D002412:Cations / Q000737:chemistry; D004396:Coloring Agents / Q000737:chemistry*; D062385:Hydroxybenzoates / Q000737:chemistry*; D017665:Hydroxyl Radical / Q000737:chemistry; D008958:Models, Molecular; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D012492:Salts / Q000737:chemistry
chemical_list: D002412:Cations; D004396:Coloring Agents; D062385:Hydroxybenzoates; D000644:Quaternary Ammonium Compounds; D012492:Salts; D017665:Hydroxyl Radical; D001622:Betaine; C017616:phenolic acid