title: Crystal violet dye in complexes with amphiphilic anionic calix[4]resorcinarenes: binding by aggregates and individual molecules.
abstract: Here, we report on a systematic study of six calix[4]resorcinarene macrocycles bearing eight carboxylic groups on the upper rim and four different lower rim substituents that are either aliphatic (2, 4, and 5) or alkylaromatic (1, 3, and 6). The macrocycles were studied in their individual aqueous solutions and in the presence of triphenylmethane dye crystal violet. It was found that binding of crystal violet with aggregated macrocycles shields it from the bulk of solution, preventing its discoloration under basic conditions and electrochemical reduction on the glassy carbon electrode. Most efficient shielding, reducing the rate of discoloration more than 173 times, as compared to solution with no macrocycle, was achieved with 6 forming aggregates of average 72 molecules in 0.1 mM solutions.
authors.affiliation: A.E. Arbuzov Institute of Organic and Physical Chemistry of Kazan Scientific Center of Russian Academy of Sciences, 8 Arbuzov str., Kazan 420088, Russia.
authors.forename: Diana A
authors.initials: DA
authors.lastname: Mironova
authors.forename: Liya A
authors.initials: LA
authors.lastname: Muslinkina
authors.forename: Victor V
authors.initials: VV
authors.lastname: Syakaev
authors.forename: Julia E
authors.initials: JE
authors.lastname: Morozova
authors.forename: Vitaliy V
authors.initials: VV
authors.lastname: Yanilkin
authors.forename: Alexander I
authors.initials: AI
authors.lastname: Konovalov
authors.forename: Ella Kh
authors.initials: EKh
authors.lastname: Kazakova
keywords: Aggregation; Calix[4]resorcinarene; Crystal violet; Electrochemical reduction; Fluorescence; Macrocycle; NMR spectroscopy; Triphenylmethane dye; UV–Vis