Location effect of an OH group on the chemiluminescence efficiency of 4-hydroperoxy-2-(o-, m-, or p-hydroxyphenyl)-4,5-diphenyl-4H-isoimidazoles

The location effect of an OH group on the chemiluminescence efficiencies of 4-hydroperoxy-2-(o-, m-, or p-hydroxyphenyl)-4,5-diphenyl-4H-isoimidazoles 4a, 4b, and 4c was investigated. The efficiency of 4a with o-OH was 0.28 times of that of lophine peroxide on the initiation with KOH/MeOH. When the trigger base was changed to TBAF/THF, the efficiency was 530-fold in a dry DMF. However, there is not such dramatic change in the efficiency for 4b with m-OH and 4c with p-OH by the change of trigger bases.