Chemiluminescence detection of five-membered heteroaromatic compounds using electrogenerated tris (2,2' -bipyridine )-ruthenium(III)

Heteroaromatic compounds, such as 2,5-dimethylthiophene, 2,5-dimethylpyrrole, and 2,5-dimethylfuran, were found to act as reducing agents for the tris(2,2′-bipyridine)ruthenium(III), Ru(bpy)33+, chemiluminescent reaction. In order to characterize the chemiluminescent reaction of Ru(bpy)33+ with heteroaromatic compounds, we have investigated various mono-, di-, and tri-heteroaromatic compounds. The π-electron density and stability of aromatic rings influence the chemiluminescent efficiency of the reaction. Above all, 2,5-dimethylthiophene produced strong chemiluminescence under acidic conditions. In addition, we confirmed that the rate of the chemiluminescent reaction of Ru(bpy)33+ with 2,5-dimethylthiophene is very fast.