Two-photon absorption properties of Zn(II) complexes: Unexpected large TPA cross section of dipolar [ZnY2(4,4′-bis(para-di-n-butylaminostyryl)-2,2′-bipyridine)] (Y = Cl, CF3CO2)

The TPA enhancement upon coordination of a TPA active ligand to a metal center may be larger in the dipolar rather than the corresponding octupolar complex, the response being easily modulated by the choice of the ancillary ligands.