LAUSR

The photophysical performance of a europium(III) complex depends on the coordination environment around the Eu3+ ion. In this work, we employed ethylenediamine to modify this coordination environment by occupying partial binding sites of the central ion before the solvent molecules and found that such parameters of the photophysical performance as lifetime and quantum yield were improved. FTIR spectroscopy, UV–vis absorption, XPS analysis, fluorescence spectroscopy, and fluorescence decay analysis were used to characterize the interactions between ethylenediamine and a Phen–Eu(III) complex, where Phen is 1,10-phenanthroline. The experimental results showed that the complex to which 0.2 mmol of ethylenediamine had been added (C-0.2) exhibited superior photophysical performance and provided a more stable coordination environment around the Eu3+ ion. The strong emission of the 5D0–7FJ (J = 1–4) transition lines of the Eu3+ ion excited at 274 nm is a result of the efficient emission of the Eu3+ ion in C-0.2. ...