High performance Europium(III) based emitters for electroluminescence: Synthesis, crystal structures, photophysical and electroluminescent properties

► Two diamine ligands and corresponding Eu(III) complexes are synthesized. ► Their crystal structures and photophysical characteristics are discussed in detail. ► Pure red emissions with a maximum EL brightness of 850 cd/m2 are obtained. ► Active hydrogen in ligand favors most PL and EL factors, except for brightness. ► A short excited state lifetime leads to a high EL brightness.