Herein we describe the synthesis, characterization and spectroscopic properties of the complex tris(thenoyltrifluoroacetonate)([1,2,5]thiadiazolo[3,4-f][1,10]phenanthroline) europium(III) acetonitrile solvate, [Eu(TTA)(3) TDPHEN] 1.5CH(3)CN, where TTA = 2-thenoyl trifluoroacetone and TDPHEN = [1,2,5] thiadiazolo[3,4-f][1, 10] phenanthroline. X-ray crystallography reveals that it is an eight-coordinate Eu(III) complex containing three beta-diketonate chelates and one N,N-bidentate ligand, [1,2,51 thiadiazolo[3,4-f][1,10] phenanthroline. The excitation at 340 nm of the europium complex in a solution of acetonitrile, and at room-temperature, showed the typical Eu(III) red emission as a sharp band at 611 nm, characteristic of Eu(III) due to the transition D-5(0) --> F-7(2). This complex also showed red emission in the solid state phase (lambda(em) = 612 nm). (C) 2008 Elsevier B.V. All rights reserved.