Observation of an Excited Singlet Charge-Transfer Complex (or a Singlet Ion Pair) Produced by Excitation of a Ground-State Complex of 1,8-Dichloroanthraquinone with 2,5-Dimethylhexa-2,4-diene

1,8-dichloroanthraquinone forms a weak ground-state complex with 2,5-dimethylhexa-2,4-diene, and its selective excitation by the picosecond 435-nm light pulse generates an excited singlet charge-transfer complex (or a singlet ion pair) with a lifetime of 100 ps.