Jump to main content
Jump to site search

Issue 6, 2012
Previous Article Next Article

The mechanism of the photochromic transformation of spirorhodamines

Author affiliations

Abstract

We investigate the equilibrium, kinetics, and mechanism of the photochromic transformation of a series of amido spirorhodamine compounds—differing in the nature of the substituents of the amido group and in the rhodamine chromophore—in ethanol at room temperature in the presence of trifluoroacetic acid. A proton participates in the equilibrium between the spiro form and the open rhodamine form. The relaxation times in the dark or under continuous irradiation show a linear dependence on the proton concentration. The slopes of these plots show a linear free energy relation with the equilibrium constant of the transformation. A mechanism involving reversible reaction steps between four states: the two thermodynamically stable isomers, a protonated spiro form, and a deprotonated open form, can account for the kinetic observations in the dark and under irradiation.

Graphical abstract: The mechanism of the photochromic transformation of spirorhodamines

Back to tab navigation
Please wait while Download options loads

Supplementary files

Publication details

The article was received on 10 Dec 2011, accepted on 26 Mar 2012 and first published on 26 Apr 2012


Article type: Paper
DOI: 10.1039/C2PP05402G
Citation: Photochem. Photobiol. Sci., 2012,11, 1081-1086
  •   Request permissions

    The mechanism of the photochromic transformation of spirorhodamines

    H. Montenegro, M. Di Paolo, D. Capdevila, P. F. Aramendía and M. L. Bossi, Photochem. Photobiol. Sci., 2012, 11, 1081
    DOI: 10.1039/C2PP05402G

Search articles by author