Picosecond laser photolysis of haloanthraquinones (XAQ; the bromo and bromochloro compounds) in toluene containing 1 M 2,5-dimethylhexa-2,4-diene (DMHD) gives rise to the appearance of absorption bands due to not only the second and lowest excited triplet states of XAQ but also a transient ionic species (an excited singlet charge-transfer complex or a singlet ion pair) generated by direct excitation of a ground-state XAQ-DMHD complex. In DMHD, similar results are also obtained for alpha-bromoanthraquinones (the l-bromo, 1,5-dibromo, and 1,8-dibromo compounds), whereas only the absorption band due to the transient ionic species is observed for the 2-bromo, 1-bromo-5-chloro, and 1-bromo-8-chloro compounds. Although this transient ionic species decomposes into the semiquinone radical of XAQ and 2,5-dimethylhexa-2,4-dien-1-yl radical, nanosecond laser photolysis indicates that a second-order reaction between these two radicals yields the corresponding haloanthrahydroquinone and a biradical (probably 2,5-dimethyl-1,3,5-hexatriene), From measurements of the molar extinction coefficients (at the 347.2-nm excitation wavelength in toluene) and the small fractions (0.03-0.13 in DMHD) of all free XAQ, the results obtained by picosecond laser photolysis of alpha-bromoanthraquinones in DMHD are ascribed to simultaneous excitation of free XAQ and the groundstate XAQ-DMHD complex; i.e., its molar extinction coefficient at 347.2 nm is very small owing to the significant reduction of a charge-transfer interaction (between DMHD and the carbonyl group of XAQ) by the bromine atom. The quenching of the lowest excited triplet states of all XAQ by DMHD is also interpreted in terms of their charge-transfer interaction.