Synthesis and electrogenerated chemiluminescence of donor-substituted phenylethynylcoumarins

Two series of donor-bearing phenylethynylcoumarins have been synthesized, and their photophysical properties have been evaluated. Chemiluminescence was observed through the annihilation of their electrogenerated radical ions and was found to be only slightly affected by the presence of various donor groups on the phenyl moiety linked through the C-C triple bond. The overall properties of the two series of compounds are discussed with respect to their structures. The observed electronic absorption properties are explained with the help of computational studies.