Maleic anhydride is modified by two long chain alcohol (1-hexadecanol, 1-octadecanol) to the corresponding monohexadecyl cis-butene dicarboxylate (MAH) and monooctadecyl cis-butene dicarboxylate (MAO), respectively. Then the two ternary europium complexes with the as-derived long chain monoester and 1,10-phenanthroline (Phen) are synthesized and characterized. Furthermore the ultra thin luminescent Langmuir-Blodgett (LB) films have been prepared by using the subphase containing Eu3+ by the film-formation ability of long chain monoester, whose luminescence has been sensitized by phen. The layer structure of the LB films is demonstrated by low-angle X-ray diffraction and the AFM study reveals that the LB films are uniform and crack free, and the films mainly consist of closely packed lines or stripes. The LB films present characteristic luminescence of Eu3+, and the signal can be detected from a single layer. (C) 2010 Elsevier B.V. All rights reserved.