Red-Emitting Dyes with Photophysical and Photochemical Properties Controlled by pH

Abstract

Series of azaphthalocyanines substituted peripherally with one substituted aniline moiety was prepared and invetsigated. The nitrogen in aniline moiety serves as donor for intramolecular charge transfer (ICT) that deactivates excited states.

In acidic media, the donor is protonated and no ICT occurs. These compounds therefore responds to changes of pH being highly fluorescent in acidic pH and non-fluorescent in neutral and basic media.

Keywords

• dyes/pigments
• fluorescence
• liposomes
• phthalocyanines
• sensors
• singlet oxygen