An investigation on the two-photon absorption activity of various terpyridines and related homoleptic andheteroleptic cationic Zn(II) complexes

The two-photon absorption (TPA) properties of various terpyridines of the kind [4'-(C6H4-(P)-X)2,2':6',2-terpyridine] and related homoleptic and heteroleptic bis(terpyridine) cationic zinc(11) complexes were investigated by the TPA induced photoluminescence (TPA-PL) method in a femtosecond regime. It appeared that terpyridines bearing an X donor group are characterized by TPA cross sections among the largest ever reported for a molecule with a dipole symmetry whereas coordination to a Zn(II) center leads to a decrease of the TPA response.