Disclosed are compounds having the formula: wherein R1 is selected from the group consisting of hydrogen, C1-C6 alkyl, amino, N—C1-C6-alkylamino, and N,N—C1-C6-dialkylamino; and ring “A” is selected from the group consisting of unsubstituted or substituted C4-C8-cycloalkenyl, unsubstituted or substituted bicyclo[2,2,1]alkenyl, and unsubstituted or substituted bicyclo[2,2,2]alkenyl, unsubstituted phenyl, and phenyl substituted with a moiety selected from the group consisting of C3-C6-alkenyl, acryl, acryl-C1-C6 alkyl, acrylamido, and acrylamido-C1-C6 alkyl; polymers made from these compounds, and ELISAs that use the compounds and polymers as a chemiluminescent detection label.