Bimodal chemiluminescence of 8-chlorostyryl-6-phenylethynylimidazopyrazinone: Large bathochromic shift caused by a styryl group at 8-position

Article abstract of DOI:10.1016/S0040-4039(97)10547-0

3,7-Dihydro-8-chlorostyryl-6-phenylethynyl-2-imidazo [1,2-a]pyrazin-3-one (5a) prepared from 2-amino-3,5-diphenylethynylpyrazine by condensation with methylglyoxal showed bimodal luminescence in DMSO, i.e., orange-colored luminescence under acidic to neutral conditions and yellow-colored luminescence under basic conditions. The large bathochromic shift of chemiluminescence caused by a styryl group at the 8 position was established by synthesizing 3,7-dihydro-8-styryl-6-phenylethynyl-2-imidazo[1,2- a]pyrazin-3-one (5b).