New europium complexes of C(6)-DTTA-appended 5-aryl-2,2′-bipyridines: synthesis, luminescence, and evaluation of their activity against cell culture

Abstract

New 5-[4(3)-R-phenyl]-2,2′-bipyridines bearing the 1,1,7,7-tetrakis(tert-butoxycarbonylmethyl)-1,4,7-triazaheptane (DTTA) moiety at the C(6) position (R = Cl, Br, CF<inf>3</inf>) and their water-soluble EuIII complexes were synthesized. The photophysical properties of the synthesized complexes were investigated. More efficient sensitization of Eu3+ cation luminescence was demonstrated for a number of halogen-containing ligands. Some chelates exhibited moderate cell-staining ability. The synthesized compounds did not show significant photodynamic activity, which may be due to the inhibition of the in situ generation of reactive oxygen species via the supposed interaction with the methylene moiety of DTTA-appended 2,2′-bipyridine ligands. © Springer Science+Business Media LLC 2024.