Abstract Twenty differently substituted 2, 2′, 2 ″, 2‴-[(2, 2′-bipyridine-6, 6′-diyl) bis (methylenenitrilo)] tetrakis (acetc acids) 75–94 were synthesized with the purpose of developing new markers to be used in bioaffinity assays based on the unique luminescence properties of Eu III and Tb III ions. The relative luminescence yields, excitation maxima, and emission decay constants were determined for the corresponding Eu III and Tb III chelates ...