Luminescence of praseodymium (III) chelates from two excited states (3P0 and 1D2) and its dependence on ligand triplet state energy

The praseodymium (III) beta -diketonate and carboxylate chelates emit visible and infrared luminescence in organic solutions at room temperature. Depending on the position of triplet level of the ligand the ff-emission of Pr3+ was observed either from two excited states (P-3(0) and D-1(2)) at 490, 605, 610, 645, 890 and 1060 nm or from the D-1(2) State only at 605, 890 and 1060 nm. For all chelates studied, the emission has low quantum yield, e.g. <0.2% for D-1(2)-luminescence of Pr(TTA)(3). 2H(2)O in DMSO. (C) 2001 Elsevier Science B.V. All rights reserved.