Strong two-photon absorptions in heteroleptic bis(phthalocyaninato) rare earth sandwich complexes

A series of heteroleptic phthalocyaninato rare earth double-decker complexes owning large two-photon absorption cross-sections were reported. The third-order nonlinear optical properties of these heteroleptic phthalocyaninato complexes were experimentally investigated by the Z-scan technique with application of femtosecond (800 nm) pulse lasers. Due to the highly delocalized π-electron system and intense π-π interactions between the phthalocyaninato macrocycles, all complexes were revealed to exhibit large two-photon absorption cross-sections with the value up to 1.83 × 105 GM, which are comparable to those efficient two-photon absorbing materials. The optical limiting behavior of these complexes in chloroform was also investigated by using femtosecond laser pulses. The excellent two-photon absorption properties and optical limiting performance indicate their good application potential in optoelectronic devices.