Abstract
Two hetero-trinuclear complexes of the type [Eu(btfa)(3)Pt-2-bPY] and [Eu(nta)(3)Pt-2-bpy] (where btfa and nta is the anion of 4,4,4-trifluoro-1-phenyl-1,3-butanedione; 4,4,4-trifluoro-1-(2-naphthyl)-1,3-butanedione, respectively and Pt(2)bpy = trans-E(Ph)(Et3P)(2)Pt-C =C-R-C C-Pt(PEt3)(2)(Ph)] (R = 2,2'-Bipyridine-6,6'-diyl) have been synthesized by the reaction between [Eu(P-diketonate)(3)(H2O)(2)] (beta-diketone = btfa and nta) and Pt(2)bpy complexes in 1:1 M ratio in THE at room temperature. The complexes have been characterized by analytical and spectroscopic methods. The complexes are soluble in common organic solvents. The photophysical properties of the novel hetero-trinuclear complexes have been analyzed by steady-state and time-resolved emission spectroscopy. The complexes exhibit typical red emission of Eu(III). The absence of any residual ligand emission in the 400-550 nm region clearly attests the efficient energy transfer from the triplet state (T1 = 20,408 cm(-1)) of Pt(2)bpy chromophore. The quantum efficiency ((J of [Eu(btfa)(3)Pt-2-bpy] (OE.- 53.95%) is 1.88 times higher than [Eu(nta)(3)Pt-2-bpy] (0Eu-28.63%), which could be due the larger value of the non-radiative decay rate-1754.41 s(-1) for [Eu(nta)(3)Pt-2-bpy] compared to A,, ad- 779.24 s(-1) for [Eu(btfa)(3)Pt-2-bpy]. Photometric characteristics of the complexes such as color correlated temperature (Ca) and luminous efficiency of the radiation (LER) suggest that the new materials may find potential application in high performance optoelectronic devices.