One- and two-photon-induced fluorescence from novel compounds formed by self-assembly of pyrrol-2-yl-methyleneamines with zinc (II)

The fluorescence properties of three novel compounds are investigated by one- and two-photon excitations. These novel compounds are formed by self-assembly of pyrrol-2-yl-methyleneamines with zinc (II), which show perfectly symmetries in molecular structures. Intensity dependent fluorescence properties of both one- and two-photon-induced fluorescence excited by an 800 nm, 70 fs laser beam are reported. The fluorescence spectra and the fluorescence lifetimes of these new compounds obtained by two-photon excitation are similar to those obtained by one-photon excitation, which indicate that the two-photon-induced photodynamic processes of these complexes are similar to one-photon-induced photodynamic processes. The two-photon excitation cross-sections of these new compounds are also measured at 800 nm. The large two-photon excitation cross-sections of these three novel compounds indicate their potential properties for two-photon applications in nonlinear optics and biomolecular imaging fields.