Large two-photon absorption of terpyridine-based quadrupolar derivatives: towards their applications in optical limiting and biological imaging.

Developing organic chromophores with large two-photon absorption (TPA) in both organic solvents and aqueous media is crucial owing to their applications in solid-state photonic devices and biological imaging. Herein, a series of novel terpyridine-based quadrupolar derivatives have been synthesized. The influences of electron-donating group, type of conjugated bridge, as well as solvent polarity on the molecular TPA properties have been investigated in detail.