Abstract |
Intrinsic photoluminescent ionic liquids based on europium(III) tetrakis(beta-diketonate) complexes with a tetraalkyl-phosphonium as the counterion were synthesized. Two are room temperature ionic liquids; [P-6,P-6,P-6,P-14][Eu(fod)(4)] (1) \fod is 1,1,1,2,2,3,3-heptafluoro-7,7-dimethyloctane-4,6-dionate\ and [P-6,P-6,P-6,P-14][Eu(fod)(3)(dbm)] (2) \dbm is dibenzoylmethanate\, while calorimetric measurements showed a melting point at 415 K for [P-6,P-6,P-6,P-14][Eu(dbm)(4)] (3). The luminescence quantum yields determined for 1, 2, and 3 are 34, 59 \%, and 64 \%, respectively. The photoluminescence and thermochemical properties of the complexes were investigated in detail and the influence of the long chain tetraalkylphosphonium counterion, together with the aromatic diketone ligand, on the unusual thermal behavior of 2 is discussed. |