Molecular first hyperpolarizability data for lanthanate complexes containing the hemicyanine chromophore

The molecular nonlinear optical polarizability, or first hyperpolarizabilit y beta, of four lanthanate complexes containing the hemicyanine 1-hexadecyl -4-{2-[4-(dimethylamino)phenyl]ethenyl}pyridinium chromophore has been dete rmined with high precision. The experimental measurement of the phase shift and the demodulation between immediate hyper-Rayleigh scattering and time- delayed multiphoton fluorescence as a function of modulation frequency allo ws for the simultaneous data analysis of phase and demodulation toward prec ise values for fluorescence-free hyperpolarizability, multiphoton fluoresce nce contribution, and fluorescence lifetime. One order of magnitude improve ment in precision is obtained with respect to the earlier analysis of demod ulation data only. This level of precision has been used to show the relati ve impact of f-orbital filling and ligands on the molecular second-order no nlinear optical response of lanthanate complexes containing a hemicyanine c hromophore. Implications for the earlier conclusions about better film form ation for lanthanate complexes are discussed.