Well-divided and pH-Dependent Bimodal Chemiluminescence of 2-Methyl-6-phenyl-8-(4-substituted phenyl)imidazo-[1,2-a]pyrazin-3(7H)-ones Induced by Superoxide Anion
作者:Ryota Saito、Chizuru Inoue、Akira Katoh
DOI:10.3987/com-03-9977
日期:——
An unprecedented pH-dependent bimodal chemiluminescence of 2methyl-6-phenyl-8-(4-substituted phenyl)imidazo[1,2-a]pyrazin-3(7H)-ones (1a and 1b) initiated by superoxide anion (O-2(.-)) in phosphate buffer solutions is described. The intensity ratio of the bimodal luminescence due to two light-emitting species, the singlet-excited neutral 2-acetamido-5-phenyl-3-(4-substituted phenyl)pyrazine [(1)(2a)* or (1)(2b)*] and its amide anion [(1)(2a(-))* or (1)(2b(-))*], varied as the pH rose. The percentage of the anionic luminescence intensity [I-anion/(I-neutral+I-anion)] for 1a showed a good linear correlation with the pH value, demonstrating the usefulness of 1a as a pH indicator as well as an O-2.(-) probe.