A CF3-substituted diphosphine dioxide ligand that enhances both photoluminescence intensity and solubility of Eu(III) complexes

摘要

The author developed the di(3-trifluoromethylphenyl)[3-(dioctylphosphinyl)propyl]phosphine oxide (DPDO-mCF(3)) ligand in order to prepare Eu(III) complexes with high photoluminescence intensity and solubility. By coordinating the DPDO-mCF(3) ligand to Eu(III), photoluminescence intensities were increased to 6.4 and 4.3 times those of tris(4,4,5,5,6,6,6-heptafluoro-1-(2-naphthyl)-1,3-hexanedionato) europium(III) (Eu(III)(hfnh)(3); 4) and tris(6,6,7,7,8,8,8-heptafluoro-2,2-dimethyl-3,5-octanedionato)europium(III) (Eu(III)(fod)(3); 5), respectively. Coordination of the DPDO-mCF(3) ligand also increased the asymmetry ratio, total photoluminescence quantum yield (Phi(TOT)), and absorbance of Eu(III) complexes. Phi(TOT) of Eu(III)(hfnh)(3)(DPDO-mCF(3)) (1) was 0.60 in ethyl acetate at a concentration of 1 x 10(-3) mol/L and 0.82 in the solid state. In addition, Phi(TOT) of Eu(III)(fod)(3) (DPDO-mCF(3)) (2) is 0.39 in ethyl acetate at a concentration of 1 x 10(-3)mol/L and 0.56 in the solid state. Solid-state quantum yields were larger than solution-state quantum yields across a wide wavelength region. Furthermore, the solubility of 2 in 2,3-dihydrodecafluoropentane (54 mu mol/g) was far higher than that of 5 (7.2 mu mol/g). DPDO-mCF(3) is thus an innovative ligand for Eu(III) complexes, and Eu(III) complexes bearing a DPDO-mCF(3) ligand are promising candidates for many applications, including LED devices, secure media, and sensing devices. (C) 2019 Elsevier B.V. All rights reserved.