Synthesis, Spectroscopic Properties, and Photophysical Properties of (2E,5E)-2-benzylidene-5-(p-dimethylaminocinnamylidene)-cyclopentanone (bdmac)

This project extends previous studies of the spectroscopic and photophysical properties of 2,5-diarylidene cyclopentanones. The focus of this research is (2E,5E)-2-benzylidene-5-(p-dimethylaminocinnamylidene)-cyclopentanone (bdmac). Absorbance and fluorescence spectra in various solvents show that maxima undergo bathochromic shifts with increasing solvent polarity. Fluorescence quantum yields and lifetimes of also vary with solvent polarity. First-order radiative and non-radiative decay constants were calculated. Geometry optimization and TD-DFT spectral calculations revealed the internal charge transfer nature of bdmac. Results were compared to data for (2E,5E)-2-(p-dimethylaminobenzylidene)-5-(p-dimethylaminocinnamylidene)-cyclopentanone (Ashrbor), a similar compound