Existence of Two Fluorescence Bands in all- trans-Polyenes with Six and Seven Double Bonds

From the analysis of UV/vis absorption, emission, and excitation of emission spectra of all- trans-α,ω-tetra- tert-butylpolyenes with six and seven double-bonds (3,14-di( tert-butyl)-2,2,15,15-tetramethyl-3,5,7,9,11,13-hexadecahexaene (ttbP6), and 3,16-di( tert-butyl)-2,2,17,17-tetramethyl-3,5,7,9,11,13,15-octadecaheptaene (ttbP7)) it is concluded that these hydrocarbons do not exhibit dual S₁/S₂ fluorescence, as could be inferred from the work of Christensen et al. [ J. Phys. Chem. A 2008 , 112 , 12629 - 12636 ]. The spectral data for ttbP6 and ttbP7 display a unique fluorescence from their S₁ states.