The synthesis, photophysical properties and two-photon absorption of triphenylamine multipolar chromophores

Triphenylamine core multipolar derivatives were synthesized via the Wittig reaction and Heck reaction and were characterized by MS, NMR, IR; melting points and decomposition temperatures were determined using differential scanning calorimetry. The photophysical as well as the linear and nonlinear spectral properties of multipolar compounds with a triphenylamine core were compared to those of corresponding dipolar compounds. The multipolar chromophores displayed large two-photon absorption and strong optical power limiting properties. An extended π-conjugated system and increased intramolecular cooperative effect are responsible for the observed, large two-photon absorption character.