The absorption and fluorescence spectral properties of several merocyanines with very high first hyperpolarizabilities in fluid solutions are reported. These molecules contain a cyanodicyanomethylidenedihydrofuran electron acceptor group and with either a pyridinylidene or quinolinylidene electron donor. The molecules also contain a bulky substituent group which has been incorporated in order to hinder molecular aggregation. No effect of merocyanine concentration on the absorption spectral distributions of these compounds was observed in any of the solvents studied indicating there was no molecular aggregation in solution. The absorption spectra of these compounds display changes in their vibronic structure in solvents with different polaritiesipolarizabilities while the fluorescence spectra exhibit the standard solvent polarity stabilizing behaviour.