Synthesis and Photoluminescence Properties of Heteroleptic Europium(III) Complexes with Appended Carbazole Units

Two europium complexes {Eu·dbm·carb·phen = tris[1‐{[6‐(9H‐carbazol‐9‐yl)hexoxy]phenyl}‐3‐{[6‐(9H‐carbazol‐9‐yl)hexoxy]phenyl}propane‐1,3‐dione](1,10‐phenanthroline)europium(III), Eu·dbm·carb·bath = tris[1‐{[6‐(9H‐carbazol‐9‐yl)hexoxy]phenyl}‐3‐{[6‐(9H‐carbazol‐9‐yl)hexoxy]phenyl}propane‐1,3‐dione](bathophenanthroline)europium(III)} and their reference compounds were synthesized and characterized. Each complex contains three different chromophores: carbazole (carb), phenanthroline (phen) (or bathophenanthroline, bath) and dibenzoylmethane (dbm) units. The luminescence properties investigated in dichloromethane solution and in solid matrix show that the carbazole moiety is a better sensitizer for the metal‐centred emitting states of the EuIII ion compared to the dibenzoylmethane and phenanthroline units. Furthermore, the charge‐transporting properties of the carbazole moieties appear to be appealing when integrated into the emitting units. Finally, the high number of appended carbazole units confers a strong light‐harvesting character to the structure.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)