Tetraphenylethene end-capped [1,2,5]thiadiazolo[3,4-c]pyridine with aggregation-induced emission and large two-photon absorption cross-sections

Two new donor-acceptor-donor-type two-photon absorption (2PA) dyes (TPEPT1 and TPEPT2) have been synthesized by Suzuki coupling reaction with tetraphenylethene (TPE) as a donor and [1,2,5]thiadiazolo[3,4-c]pyridine (PT) as an acceptor. The 2PA cross sections (σ) values of these dyes measured by the open aperture Z-scan technique are up to 6030 and 2360 GM, respectively. Both of them exhibit good aggregation-induced emission (AIE) properties with fluorescent quantum efficiencies of 7.25% and 5.53% in the red channel. Finally, TPEPT1 with higher brightness was used to perform a cell-imaging proposal.