Non-fluorescing excited states of alkanes

Non-fluorescing excited states of alkanes. Several relatively long-lived non-fluorescing ( dark ) excited states of hydrocarbons capable of sensitizing singlet solute luminescence have been proposed in recent years. 

The strongest evidence of such states is from the work of Lipsky and coworkers [98-100] who have shown that the sensitization of solute fluorescence by transfer of energy from the photoexcited solvent (cyclohexane, n-hexadecane, 2,3-dimethylbutane, and cis- and trans-decalins) can be explained by the participation of two solvent excited states the fluorescent Si state and a 

---