Hexatriene electronic spectrum

Namjesnik-Dejanovic K, Maurice PA (2001) Conformational and aggregate structures of sorbed natural organic matter on muscovite and hematite. Geochim Cosmochim Acta 65 1047-1057 Naves de Brito A, Svensson S, Correia N, Keane MP, Agren H, Sairanen OP, Kivimaki A, Aksela S (1992) X-ray induced electron yield spectrum of thin films of 1,3-trans-butadiene and 1,3,5-trans-hexatriene. J Electron Spect Rel Phen 59 293-305... 

There are instances where comparison of the natural lifetime, measured lifetime, and quantum yield can be informative. For instance, in the case of the widely used membrane probe 1,6-diphenyl-1,3,5-hexatriene (DPH) the measured lifetime—near 10 ns—is much longer than that calculated from Eq. [1.1], which is near 1.5 ns. In this case die calculation based on the absorption spectrum of DPH is incorrect because the absorption transition is to a state of different electronic symmetry than the emissive state. Such quantum-mechanical effects are rarely seen in more complex fluorophores with heterocyclic atoms. 

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