Photo-modulation of the two-photon excited fluorescence of dithienylethene bis-(1-pyrenyl) compounds: An experimental and theoretical study

Photomodulation of two-photon excited fluorescence has been effectively controlled in 1-pyrene-based dithienylethenes. The specific molecular design enables photocommutation of two-photon excited fluorescence during sequential one- and two-photon excitations without interference nor destructive optical readout. Theoretical studies have concluded that the internal functionalization of pyrene is responsible for the photoactivity in these systems. Photophysical studies indicate that the presence of a second laterally introduced pyrene is crucial for maintaining high photocommutation contrast and durability. • Synthesis of new unsymmetrical pyrene-based DTE compound. • Photo-control of two-photon excitation signal. • Photo-switchable, all-optical, non-destructive molecular system. • Influence of the position of the pyrenes on the photophysical behavior. • Photo-modulation upon alternation of two- and one-photon excitation.