Absorption and emission spectra of tetracene in benzene solution are shown in Figure 1. The absorption and fluorescence bands correspond to the S0 (ground state) ā S1 (first excited state) transition.
a) Assign the vibronic transitions in the figure.
b) Draw the energy diagram that shows the vibronic transitions assignments (use v for S0 and v' for S1). Using the peak values, write the energies of the separations in cm-1.
c) Which vibrational mode is responsible for these vibronic transitions? Identify only one mode and justify your answer.
d) The extinction coefficient is 10,000 M-1cm-1 at 475 nm. Determine the amount of tetracene you need to make a solution that has optical density (OD) = 0.1 at 475 nm in 0.1 cm cuvette. Molecular weight of tetracene is 228.29.