New luminescent heteronuclear Ln(III)–Bi(III) complexes (Ln = Nd, Eu, Tb, Yb) based on aminopolycarboxylic acids

Abstract

New heteronuclear Ln(III)–Bi(III) complexes (Ln = Nd, Eu, Tb, Yb, Lu) with ethylenediamine-N,N,N′,N′-tetraacetic (H4edta), trans-1,2-cyclohexane-diamine-N,N,N′,N′-tetraacetic (H4cdta), diethylenetriamine-N,N,N′,N″,N″-pentaacetic (H5dtpa), and triethylenetetraamine-N,N,N′,N″,N″′,N″′-hexaacetic (H6ttha) acids have been synthesized with a different synthetic approach. Bi(III) is a sensitizer of the 4f-luminescence in visible and near IR region. Emission spectra of Eu(III)–Bi(III) complexes were studied and the asymmetry of Eu(III) coordination environment was estimated, in good agreement with molecular models. The complexes synthesized by self-assembly are characterized by higher values of the 4f-luminescence quantum yield than other Ln(III)–Bi(III) complexes.