Photodissociation of pyrene dimer radical cation during the pulse radiolysis–laser flash photolysis combined method

摘要: Photodissociation of pyrene (Py) dimer radical cation (Py2∙+) giving (Py∙+) and Py subsequent regeneration Py2∙+ by association Py∙+ were directly observed during the pulse radiolysis–laser flash photolysis combined method at room temperature. When was excited local excitation band with 532-nm laser flash, rapid growth decay monomeric 460 nm. The dissociation proceeded via a one-photon process to give ground-state Py∙+(D0) in quantum yield (Φdiss) (2.9 ± 0.9) × 10−3. It shown that decayed time constant several tens nanoseconds, indicating regenerating proceeds diffusion-controlled rate. photodissociation from lowest state Py2∙+, even when higher state. difference between Φdiss value previously reported for naphthalene (Np2∙+) is discussed.