Articles written in Journal of Chemical Sciences
Volume 110 Issue 3 June 1998 pp 311-317
The effects of several biologically-important inorganic salts (NaCl, KCl, MgCl2, MgSO4, CaCl2, EuCl3 and Er(CH3COO)3) on the electronic absorption and fluorescence spectra of merocyanine 540 (MC-540) have been determined in aqueous media. Depending on both the MC-540 concentration and the nature of salt, a new absorption band is obtained, above a threshold of salt concentration. The cations produce two types of fluorescence quenching according to their charge: in the case of monovalent ions (Na+, K+), a nonlinear Stern-Volmer behaviour is observed, while for divalent alkaline-earth (Mg2+, Ca2+) and trivalent lanthanide (Eu3+, Er3+) ions, linear Stern-Volmer relationships are established. Our results, which exclude the presence of protonated MC-540, demonstrate the existence of interactions between the inorganic ions and the MC-540 highly polar zwitterionic structure followed by an ion-induced aggregation of the dye.
Volume 134, 2022
Continuous Article Publishing mode
Click here for Editorial Note on CAP Mode