Inter- and Intramolecular Energy Transfer Processes. I. Nitro-Compounds and Hydrocarbons

The addition compounds of aromatic nitro-compounds and hydrocarbons fluoresce appreciably only if the hydrocarbon component itself has a possible transition lying in the region where the nitro-complex might be expected from its absorption to emit. The resulting emission spectrum is very similar to that of the hydrocarbon component but much more strongly allowed. This is attributed to the breaking down of the S←T selection rule as the complex dissociates.