Synthesis, characterization, and reversible oxygen binding of β-diketonate–Eu(III) complexes bearing anthracene

Abstract

A series of β-diketonate–Eu(III) complexes with the general formula [EuX3L] {X = benzoyltrifluoroacetonate (BTA), naphthoyltrifluoroacetonate (NTA); L = N,N-dimethyl-N′-(9-methylanthracenyl)ethylenediamine (L1), 1,2-bis[(anthracen-9-ylmethyl)amino]ethane (L2)} has were newly prepared and structurally elucidated by single crystal X-ray diffraction. The complexes displayed anthracene-based absorption bands and weak red emissions which were remarkably changed upon reaction with singlet oxygen (1O2). The strong red emission of endoperoxides [EuX3L-EPO] became almost indiscernible after 1.5 h at room temperature, making oxygen binding of β-diketonate–Eu(III) complexes reversible.