(DICYANOMETHYLENE)PYRAN DERIVATIVES WITH C2V SYMMETRY : AN UNUSUAL CLASS OF NONLINEAR OPTICAL CHROMOPHORES

摘要: A series of symmetric derivatives 4-(dicyanomethylene)-2-methyl-6-(p-(dimethylamino)styryl)-4H-pyran (DCM laser dye) has been synthesized, and the nonlinear optical properties thermal decomposition temperatures each chromophores measured. The all have larger hyperpolarizabilities than one would expect based on their absorption maxima. Estimations oscillator strengths upon UV/vis spectra are well above 1.0. It is proposed that these compounds possess two excited electronic states close to other in energy, both contributing hyperpolarizability an additive fashion. Electro-optical spectroscopy data semiempirical calculations a model compound support this hypothesis. implications results with regard tradeoff between nonlinearity transparency discussed. large dipole moments high make them attractive candidates for use electr...