IONIC PHOTODISSOCIATION OF POLYENES VIA A HIGHLY POLARIZED SINGLET EXCITED-STATE

Several polyene acetates and polyene methyl ether were prepared. Upon direct excitation these polyenes undergo ionic photodissociation from their singlet excited states. Triplet-sensitization experiments on these polyenes revealed that the ionic photodissociation process is restricted to singlet excited states. The rationale put forward is that the polyene chromophore undergoes charge separation/polarization in the singlet excited state, which leads to ionic photodissociation.