Highly Solvatochromic 7-Aryl-3-hydroxychromones

LUCIANA GIORDANO; VOLODYMYR V. SHVADCHAK; JONATHAN A. FAUERBACH; ELIZABETH A. JARES-ERIJMAN; THOMAS M. JOVIN

The Journal of Physical Chemistry Letters

American Chemical Society

Año: 2012 vol. 3 p. 1011 - 1016

1948-7185

Introduction of the dialkylaminophenyl group in position 7 of 3-hydroxychromone changes the orientation of the excited-state dipole moment and leads to superior solvatochromic properties (>170 nm emission shift in aprotic media). The excited-state intramolecular proton-transfer (ESIPT) reaction of 7-aryl-3-hydroxychromones is almost completely inhibited in most solvents. Methylation of the 3-OH abolishes ESIPT completely and also leads to improved photostability. The probes exhibit a 100-fold increase in fluorescence intensity and large Stokes shifts upon binding to membranes, reflecting differences in membrane phase and charge by a >40 nm spread in the emission band position.