Fluorescence spectrum of α,ω-diphenyltetradecaheptaene in a rigid matrix at 77 K

Emission spectra of α,ω-diphenyltetradecaheptaene (DP7) have been measured in polycrystalline n-tetradecane at 77 K. It is shown that DP7 exhibits the dual fluorescence from the 21Ag (S1) and 11Bu (S2) states not only in room temperature solution but also in a rigid matrix at 77 K. The measured fluorescence spectrum at 77 K was compared with the spectrum simulated with sum of Gaussians. The measured and calculated spectra agreed reasonably to each other, and the energy for the 21Ag (S1) to 11Ag (S0) fluorescence origin band was determined to be 16 660 ± 40 cm−1 in n-tetradecane at 77 K.