Aqueous on/off fluorescent switches based on systems of quinoline / quinoline-macrocycle

CARRANZA, MATÍAS E; ELERO, HUGO M.; VEGLIA, ALICIA V.

JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY

ELSEVIER SCIENCE SA

Lugar: Amsterdam; Año: 2020 vol. 390 p. 1 - 1

1010-6030

he changes in the spectrophotometric and the spectrofluorimetric properties ofQuinoline (QUI) by the addition of water soluble macrocycles with differentcharacteristics such as cyclodextrins (CD; , , hydroxypropyl-, methyl- and ) andsulfonate calixarenes (SCAn, n= 6 and 8) were analyzed at acidic and neutral pH at25.0 ºC. Spectral changes were observed for the basic form of QUI. Small decreases ofabsorbance were indicative of interactions between QUI and the macrocycles. Theassociation constants were determined in the cases of QUI-CD and QUI-CD. In allcases, the fluorescence of QUI was quenched in the presence of the macrocycles. Thevalues of the Stern-Volmer constants (KQ/M-1) were (54.030  0.001) and (57.050 0.001) for CD and CD and (3.8  0.1) x 104 and (2.40  0.06) x 104 for SCA6 andSCA8. These values were interpreted as the association constants (KA) of the nonfluorescent comple