One-electron oxidation of alcohols such as methanol, ethanol, and 2-propanol by 1,3,5-trimethoxybenzene radical cation (TMB center dot+) in the excited state (TMB center dot+*) was observed during the two-color two-laser flash photolysis. TMB center dot+ was formed by the photoinduced bimolecular electron-transfer reaction from TMB to 2,3,5,6-tetrachlorobenzoquinone (TCQ) in the triplet excited-state during the first 355-nm laser flash photolysis. Then, TMB center dot+* was generated from the selective excitation of TMB center dot+ during the second 532 nm laser flash photolysis. Hole transfer rate constants from TMB center dot+* to methanol, ethanol, and 2-propanol were calculated to be (5.2 +/- 0.5) x 10(10), (1.4 +/- 0.3) x 10(11), and (3.2 +/- 0.6) x 10(11) M-1 s(-1), respectively. The order of the hole transfer rate constants is consistent with oxidation potentials of alcohol. Formation of TCQH radical (TCQH(center dot)) with a characteristic absorption peak at 435 nm was observed in the microsecond time scale, suggesting that deprotonation of the alcohol radical cation occurs after the hole transfer and that TCQ radical anion (TCQ(center dot-)), generated together with TMB center dot+ by the photoinduced electron-transfer reaction, reacts with H+ to give TCQH(center dot).